federal register /vol. 61, no. 28/friday, february 9, … · from a bunsen or tirrill burner must...

5171Federal Register / Vol. 61, No. 28 / Friday, February 9, 1996 / Rules and Regulations

flame must be 1550°F. Suitable precautionsmust be taken to avoid drafts. The flame mustbe applied for 30 seconds with one-thirdcontacting the material at the center of thespecimen and then removed. Flame time,glow time, and whether the flame penetrates(passes through) the specimen must berecorded.

(g) Sixty-degree test. A minimum of threespecimens of each wire specification (makeand size) must be tested. The specimen ofwire or cable (including insulation) must beplaced at an angle of 60 degrees with thehorizontal in the cabinet specified inparagraph (c) of this appendix, with thecabinet door open during the test or placedwithin a chamber approximately 2 feet high× 1 foot × 1 foot, open at the top and at onevertical side (front), that allows sufficientflow of air for complete combustion but isfree from drafts. The specimen must beparallel to and approximately 6 inches fromthe front of the chamber. The lower end ofthe specimen must be held rigidly clamped.The upper end of the specimen must passover a pulley or rod and must have anappropriate weight attached to it so that thespecimen is held tautly throughout theflammability test. The test specimen spanbetween lower clamp and upper pulley orrod must be 24 inches and must be marked8 inches from the lower end to indicate thecentral point for flame application. A flamefrom a Bunsen or Tirrill burner must beapplied for 30 seconds at the test mark. Theburner must be mounted underneath the testmark on the specimen, perpendicular to thespecimen and at an angle of 30 degrees to thevertical plane of the specimen. The burnermust have a nominal bore of three-eighthsinch, and must be adjusted to provide athree-inch-high flame with an inner coneapproximately one-third of the flame height.The minimum temperature of the hottestportion of the flame, as measured with acalibrated thermocouple pyrometer, may notbe less than 1,750 °F. The burner must bepositioned so that the hottest portion of theflame is applied to the test mark on the wire.Flame time, burn length, and flaming timedrippings, if any, must be recorded. The burnlength determined in accordance withparagraph (h) of this appendix must bemeasured to the nearest one-tenth inch.Breaking of the wire specimen is notconsidered a failure.* * * * *

PART 91—GENERAL OPERATING ANDFLIGHT RULES

46. The authority citation for part 91continues to read as follows:

Authority: 49 U.S.C. 1301(7), 1303, 1344,1348, 1352 through 1355, 1401, 1421 through1431, 1471, 1472, 1502, 1510, 1522, and 2121through 2125; Articles 12, 29, 21, and 32(a)of the Convention on International CivilAviation (61 Stat. 1180); 42 U.S.C. 4321 etseq.; E.O. 11514; 49 U.S.C. 106(g).

47. Section 91.205 is amended byredesignating paragraphs (b)(11) through(b)(16) as paragraphs (b)(12) through(b)(17), respectively, and by adding a

new paragraph (b)(11) to read asfollows:

§ 91.205 Powered civil aircraft withstandard category U.S. airworthinesscertificates: Instrument and equipmentrequirements.

* * * * *(b) * * *(11) For small civil airplanes

certificated after March 11, 1996, inaccordance with part 23 of this chapter,an approved aviation red or aviationwhite anticollision light system. In theevent of failure of any light of theanticollision light system, operation ofthe aircraft may continue to a locationwhere repairs or replacement can bemade.* * * * *

48. Section 91.209 is revised to readas follows:

§ 91.209 Aircraft lights.

No person may:(a) During the period from sunset to

sunrise (or, in Alaska, during the perioda prominent unlighted object cannot beseen from a distance of 3 statute milesor the sun is more than 6 degrees belowthe horizon)—

(1) Operate an aircraft unless it haslighted position lights;

(2) Park or move an aircraft in, or indangerous proximity to, a night flightoperations area of an airport unless theaircraft—

(i) Is clearly illuminated;(ii) Has lighted position lights; or(iii) is in an area that is marked by

obstruction lights;(3) Anchor an aircraft unless the

aircraft—(i) Has lighted anchor lights; or(ii) Is in an area where anchor lights

are not required on vessels; or(b) Operate an aircraft that is

equipped with an anticollision lightsystem, unless it has lightedanticollision lights. However, theanticollision lights need not be lightedwhen the pilot-in-command determinesthat, because of operating conditions, itwould be in the interest of safety to turnthe lights off.

Issued in Washington DC, on January 29,1996.David R. Hinson,Administrator.[FR Doc. 96–2083 Filed 2–8–96; 8:45 am]BILLING CODE 4910–13–M

14 CFR Parts 1 and 23

[Docket No. 27807; Amendment Nos. 1–43,23–50]

RIN 2120–AE61

Airworthiness Standards; Flight RulesBased on European Joint AviationRequirements

AGENCY: Federal AviationAdministration, DOT.ACTION: Final rule.

SUMMARY: This final rule amends theflight airworthiness standards fornormal, utility, acrobatic, and commutercategory airplanes. This amendmentcompletes a portion of the FederalAviation Administration (FAA) and theEuropean Joint Aviation Authorities(JAA) effort to harmonize the FederalAviation Regulations and the JointAviation Requirements (JAR) forairplanes certification in thesecategories. This amendment willprovide nearly uniform flightairworthiness standards for airplanescertificated in the United States under14 CFR part 23 and in the JAA countriesunder Joint Aviation Requirement 23,simplifying international airworthinessapproval.EFFECTIVE DATE: March 11, 1996.FOR FURTHER INFORMATION CONTACT:Lowell Foster, ACE–111, Small AirplaneDirectorate, Aircraft CertificationService, Federal AviationAdministration, 601 East 12th Street,Kansas City, Missouri 64106; telephone(816) 426–5688.

SUPPLEMENTARY INFORMATION:

Background

This amendment is based on Notice ofProposed Rulemaking (NPRM) No. 94–22 (59 FR 37878, July 25, 1994). Allcomments received in response toNotice 94–22 have been considered inadopting this amendment.

This amendment completes part of aneffort to harmonize the requirements ofpart 23 and JAR 23. The revisions topart 23 in this amendment pertain toflight airworthiness standards. Threeother final rules are being issued in thisFederal Register that pertain toairworthiness standards for systems andequipment powerplant, and airframe.These related rulemakings are also partof the harmonization effort. Interestedpersons should receive all four finalrules to ensure that all revisions to part23 are recognized.

The harmonization effort wasinitiated at a meeting in June 1990 of theJAA Council (consisting of JAAmembers from European countries) and

5172 Federal Register / Vol. 61, No. 28 / Friday, February 9, 1996 / Rules and Regulations

the FAA, during which the FAAAdministrator committed the FAA tosupport the harmonization of the UnitedStates regulations with the JAR thatwere being developed. In response tothe commitment, the FAA SmallAirplane Directorate established an FAAHarmonization Task Force to work withthe JAR 23 Study Group to harmonizepart 23 with the proposed JAR 23. TheGeneral Aviation ManufacturersAssociation (GAMA) also established aJAR 23/part 23 committee to providetechnical assistance.

The FAA, JAA, GAMA, and theAssociation Europeanne desConstructeurs de Material Aerospatial(AECMA), an organization of Europeanairframe manufacturers, met on severaloccasions in a continuingharmonization effort.

Near the end of the effort toharmonize the normal, utility, andaerobatic category airplaneairworthiness standards, the JAArequested and receivedrecommendations from its membercountries on proposed airworthinessstandards for commuter categoryairplanes. Subsequent JAA and FAAmeetings on this issue resulted inproposals that were reflected in NoticeNo. 94–22 to revise portions of the part23 commuter category airworthinessstandards. Accordingly, this final ruleadopts the flight airworthinessstandards for all part 23 airplanes.

In January 1991, the FAA establishedthe Aviation Rulemaking AdvisoryCommittee (ARAC) (56 FR 2190, January22, 1991). At an FAA/JAAHarmonization Conference in Canada inJune 1992, the FAA announced that itwould consolidate the harmonizationeffort within the ARAC structure. TheFAA assigned to ARAC the rulemakingsrelated to JAR/part 23 harmonization,which ARAC assigned to the JAR/FAR23 Harmonization Working Group. Theproposal for flight airworthinessstandards contained in Notice No. 94–22 were a result of both the workinggroup’s efforts and the efforts atharmonization that occurred before theformation of the working group.

The JAA submitted comments to theFAA on January 20, 1994, in responseto the four draft proposals forharmonization of the part 23airworthiness standards. The JAAsubmitted comments again during thecomment period of the NPRM. At theApril 26, 1995, ARAC JAR/FAR 23Harmonization Working Group meeting,the JAA noted that many of thecomments in the January 20 letter hadbeen satisfied or were no longerrelevant. The few remaining itemsconcern issues that are considered

beyond the scope of this rulemakingand, therefore, will be dealt with atfuture FAA/JAA Harmonizationmeetings.

Discussion of Comments

General

Interested persons were invited toparticipate in the development of thesefinal rules by submitting written data,views, or arguments to the regulatorydocket on or before November 21, 1994.Four commenters responded to NoticeNo. 94–22. Minor technical andeditorial changes have been made to theproposed rules based on relevantcomments received, consultation withARAC, and further review by the FAA.

Discussion of Amendments

Section 1.1 General Definitions

The FAA proposed to amend § 1.1 toadd a definition of ‘‘maximum speed forstability characteristics, VFC/MFC.’’ Thischange harmonizes part 1 and JAR 1.The definition is deleted from§ 23.175(b)(2).

No comments were received on theproposal for this section, and it isadopted as proposed.

Section 23.3 Airplane Categories

The FAA proposed to revise§ 23.3(b)(2) to add an outside limit of 90degrees in angle of bank for lazy eights,chandelles, and seep turns.

The FAA proposed to revise § 23.3(d)to remove chandelles and lazy eights asapproved operations in commutercategory airplanes. The FAA does notanticipate any operational need for suchmaneuvers.

The FAA proposed to revise § 23.3(e)to prohibit type certification ofcommuter category airplanes in anyother category. This rule change will notpreclude the type certification of similarairplanes with different model numbers,such as the present Cessna models 500and 501.

No comments were received on theproposals for this section, and they areadopted as proposed.

Section 23.25 Weight Limits

The FAA proposed to revise § 23.25(a)to clarify that the maximum weight thatmust be selected is the least of the threechoices given in § 23.25(a)(1). The FAAproposed to remove the commutercategory zero fuel weight requirementfrom current § 23.25(a). The requirementwas proposed to be removed to § 23.343by the airframe NPRM, Notice No. 94–20 (59 FR 35198, July 8, 1994). The FAAproposed to remove the reference tostandby power rocket engines in§ 23.25(a)(1)(iii) and to remove

appendix E because this is a rare andobsolete design feature. If amanufacturer proposed to use thisapproach, the FAA would issue specialconditions to ensure adequateairworthiness.


Section 23.33 Propeller Speed andPitch Limits

The FAA proposed to revise§ 23.33(b)(1) to remove the reference toVY and to replace it with ‘‘the allengine(s) operating climb speedspecified in § 23.65,’’ to be consistentwith other changes in performancerequirements. The FAA proposed torevise § 23.33(b)(2) to use ‘‘VNE’’ inplace of ‘‘never exceed speed,’’ sinceVNE is defined in part 1, and to removethe word ‘‘placarded,’’ which isunnecessary.


Section 23.45 GeneralIn Notice of Proposed Rulemaking,

Small Airplane Airworthiness ReviewProgram Notice No. 4, Notice No. 90–18(55 FR 26534, June 28, 1990), the FAArequested comments on the need forweight, altitude, and temperature(WAT) criteria, as information or as alimitation on piston-powered, twin-engine part 23 airplanes. The FAA alsorequested comments about WAT criteriaon turbine-powered twin-engine part 23airplanes, specifically during takeoffand landing.

WAT criteria is used to determine themaximum weight an airplane can havein relation to altitude and temperaturefor safe takeoff. This criteria providespilots with the information needed todetermine if a takeoff and climb can besuccessfully completed if one enginebecomes inoperative. WAT criteria hasbeen required under part 23 forcommuter category airplanes, at allapproved altitudes. A limited WATcriteria has been required for turbineengine powered airplanes at 5,000 feetand at standard temperature plus 40°F,but not for higher altitudes ortemperatures. For multiengine poweredairplanes, WAT data has been providedby the manufacturer as information topilots.

The FAA received three comments onmandating WAT criteria in part 23 andaddressed these comments in detail inthe preamble to Notice 94–22.

Based on statistics and conclusionsfrom an FAA 1991 study (discussed indetail in Notice 94–22) and oncomments, the FAA determined that


WAT limits are necessary for safeoperation of multiengine airplanes ofthe type that will be involved intransporting passengers for hire.

The FAA proposed a completerevision of § 23.45 to require weight,altitude, and temperature (WAT)performance accountability for normal,utility, and acrobatic airplanes with amaximum takeoff weight over 6,000pounds and all turbine-poweredairplanes.


Section 23.49 Stalling SpeedThe FAA proposed to revise § 23.49

by reorganizing and editing it forclarification. The FAA’s proposedclarification merges, in paragraph (a),the VSO and VS1 requirements, whichwere separated with parallelconfiguration items under paragraphs(a) and (d).

Other proposed changes to paragraph(a) are as follows:

(1) Proposed paragraph (a)(4) is arequirement that the airplane be in thecondition existing in the test, in whichVSO and VS1 are being used.

(2) Proposed paragraph (a)(5) is arevised version of current paragraph(a)(6). The current requirement statesthat the center of gravity must be in themost unfavorable position within theallowable landing range. The proposedrequirement would state that the centerof gravity must be in the position thatresults in the highest value of VSO andVS1.

(3) Current paragraph (a)(5) is movedto § 23.45(c).

These changes are clarifying and arenot an increase in requirements. Theonly comment received was from JAA,noting the existing disharmony betweenthe JAR and the FAR concerning a VSO

more than 61 knots for single-engineairplanes and multiengine airplanes of6,000 pounds maximum weight or lessthan do not meet the required minimumrate of climb.

The proposal is adopted as proposed.

Section 23.51 Takeoff Speeds

The FAA proposed to change theparagraph heading from ‘‘Takeoff’’ to‘‘Takeoff speeds’’ and to incorporate thetakeoff speed requirements currentlycontained in § 23.53. This revision tothe heading and the reorganization oftakeoff requirements is proposed forharmony with JAR 23.

The FAA proposed to move current§ 23.51(a) to § 23.53(a). Currentparagraph (a) requires that the distancerequired to take off and climb over a 50-foot obstacle must be determined with

the engines operating within approvedoperating limitations and with cowlflaps in the normal takeoff position.These requirements for power and cowlflaps are now covered in final § 23.45,paragraphs (c) and (d), and in § 23.1587.

The FAA proposed to remove current§ 23.51(b) on measuring seaplane andamphibian takeoff distances. It is astatement of an acceptable method ofcompliance, and there is no need toaddress a separate seaplane startingpoint.

The FAA proposed to remove current§ 23.51(c) concerning pilot skills andconditions. It is covered under thegeneral requirements in proposed§ 23.45(f).

The FAA proposed to remove current§ 23.51(d). The requirements arecovered under § 23.45 in commutercategory performance and otherperformance requirements, and theinformation requirements are coveredunder § 23.1587.

For multiengine normal, utility, andacrobatic category airplanes, the FAAproposed to transfer the determinationof VR from § 23.53(a) to § 23.51(a) withminor changes in the specified rotationspeed. For multiengine airplanes inproposed paragraph (a)(1), the marginbetween rotation speed and VMC or amargin of 1.10 VS1 is establishedbetween VR and stall.

The FAA proposed to define VR, inproposed paragraph (a), as the speed atwhich the pilot makes a control inputwith the intention of lifting the airplaneout of contact with the runway or watersurface. This definition would apply totail wheel and tricycle gear airplanes,seaplanes, and single-engine airplanes.

The FAA also proposed to includerotation speeds for single-engineairplanes, seaplanes, and amphibians inparagraph (a). This extends VR

applicability to all part 23 airplanes toestablish a safe and standardizedprocedure that can be used by pilots toachieve AFM takeoff performance. Thisuse of rotation speed is consistent withpart 25.

In proposed paragraph (b), the speedat 50 feet is based on current § 23.53(b)with no change in requirements.

For commuter category airplanes, theFAA proposed to move the takeoffspeed requirements from § 23.53(c) toproposed § 23.51(c) with editorialchanges. The option is added, inproposed (c)(1)(i), for an applicant todetermine a VMCG and to establish a V1

based on VMCG rather than a marginabove VMCA.

The only comment on this sectionwas a non-substantive one, in whichFAA concurred.


Section 23.53 Takeoff Performance

The FAA proposed a new heading for§ 23.53 and a content based primarily onthe general takeoff performancerequirement of the current § 23.51.

The FAA proposed to remove thetakeoff speed requirements from current§ 23.53 and to place them in § 23.51.(See discussion for § 23.51.) Section23.53 provides general takeoffperformance requirements for normal,utility, acrobatic, and commutercategory airplanes. Proposed paragraph(a) is based on current § 23.51(a).Proposed paragraph (b) is a modificationof current § 23.1587(a)(5). Proposedparagraph (c) is based on current§ 23.51(d).


Section 23.55 Accelerate-StopDistance

The FAA proposed to revise § 23.55 toclarify the accelerate-stop segments andto make editorial changes.

The proposed requirement divides theaccelerate-stop maneuver into threesegments, rest to VEF (paragraph (a)(1)),VEF to V1 (paragraph (a)(2)), and V1 torest (paragraph (a)(3)). The FAAproposed to remove the following fourphrases: First, remove the phrase ‘‘in thecase of engine failure,’’ from current§ 23.55(a)(2) because it is included inparagraph (a)(2). Second, remove thephrase ‘‘assuming that * * * the pilothas decided to stop as indicated byapplication of the first retarding meansat the speed V1,’’ from § 23.55(a)(2)because it is stated in § 23.51(c)(1)(ii).Third, remove the phrase ‘‘exceptionalskill’’ from § 23.55(b)(3) because itremains in § 23.45(h)(5)(i). Fourth,remove the phrase ‘‘if that means isavailable with the critical engineinoperative’’ from § 23.55(b) because itis covered by the safe and reliablerequirements of § 23.55(b)(1).


Section 23.57 Takeoff Path

The FAA proposed to revise § 23.57 toclarify and to specify the takeoff pathsegments that must be determined inflight. Proposed paragraph (a) clarifiesthat the transition to the enrouteconfiguration should be completed onor before reaching 1500 feet above thetakeoff surface. Section 23.57(c)(1)requires the slope of the airborne part ofthe takeoff path to be ‘‘positive at eachpoint’’; proposed paragraph (c)(1) isrevised to ‘‘not negative at any point,’’to allow acceleration in level flight,


which is implied by current § 23.61(c).Proposed § 23.57(c)(3) specifies that theclimb gradient ‘‘must not be less than* * *,’’ as opposed to ‘‘may not be lessthan * * *.’’ The option, in current§ 23.57(d), to determine the takeoff patheither by continuous demonstration orby synthesis from segments, does notreflect current practice. The best methodto determine the takeoff path from restto 35 feet above the takeoff surface is bya continuous demonstration. The mostpractical method to determine thetakeoff path from 35 feet to 1500 feetabove the takeoff surface is by synthesisfrom segments. Accordingly, § 23.57,paragraphs (d) and (e), incorporatesthese changes.


Section 23.59 Takeoff Distance andTakeoff Run

The FAA proposed to clarify § 23.59with no substantial change inrequirements. A change to the openingtext is proposed to clarify that thedetermination of takeoff run is theapplicant’s option since the applicantmay choose not to present clearwaydata. In current § 23.59 (a)(2) and (b)(2),the reference to ‘‘along the takeoffpath,’’ in a takeoff with all enginesoperating, is proposed to be removedsince takeoff path is a one-engine-inoperative condition. Additionally, theFAA proposed to replace the referenceto VLOF with the words ‘‘liftoff point’’ toclarify that the requirements specify apoint and related distance, not a speed.


Section 23.63 Climbs: GeneralThe FAA proposed a new § 23.63 to

assemble general climb requirementsfrom current §§ 23.65 and 23.67 into asingle section and to differentiatebetween WAT limited airplanes andthose airplanes that are not WATlimited. (See discussion under § 23.45.)As proposed, new § 23.63(a)(1) requiresthat compliance be shown out of groundeffect. This requirement is in current§ 23.67(e), which applies to commutercategory airplanes. New § 23.63(a)(3)requires that compliance must beshown, unless otherwise specified, withone engine inoperative, at a bank anglenot exceeding 5 degrees. Thisrequirement is in current § 23.149 andhas been applied generally to part 23airplanes except commuter categoryairplanes in certain circumstances.


Section 23.65 Climb: All EnginesOperating

The FAA proposed to change theapplicability of § 23.65(a) from ‘‘eachairplane,’’ as adopted in AmendmentNo. 23–45 (58 FR 42136, August 6,1993), to ‘‘each normal, utility, andacrobatic category reciprocating engine-powered airplane of 6,000 pounds orless maximum weight.’’ The FAA alsoproposed to change the phrase ‘‘angle ofclimb’’ to ‘‘climb gradient’’ and toestablish the climb gradient at 8.3percent for landplanes and 6.7 percentfor seaplanes and amphibians withcertain specified performanceconditions.

In paragraph (a)(4), the FAA proposedto establish a minimum climb speed formultiengine airplanes of not less thanthe greater of 1.1 VMC and 1.2 VS1,which provides a margin above VMC.

The FAA proposed to move cowl flaprequirements, in current paragraph(a)(5), to proposed § 23.45(c).

The FAA proposed to remove§ 23.65(b) since these requirementsshould have been removed inAmendment No. 23–45 (58 FR 42136,August 6, 1993). Since the adoption ofAmendment No. 23–45, there is nolonger a rate of climb requirement in§ 23.65(a).

The FAA proposed to add WAT limitsto § 23.65(b), for reciprocating engine-powered airplanes of more than 6,000pounds maximum weight and turbineengine-powered airplanes. (See § 23.45discussion.)

The FAA proposed to move § 23.65(c)to § 23.65(b) and to remove thetemperature and altitude requirementssince WAT limits are required forturbine engine-powered airplanes andthe four percent gradient applies at anyapproved takeoff ambient condition. In§ 23.65(b)(2), the FAA proposed torequire the landing gear be down for thetest unless the gear can be retracted innot more than seven seconds. This ismore stringent than the presentrequirement, but the same as theproposed one-engine-inoperative takeoffclimb requirements, and is consideredappropriate to this weight and class ofairplane with WAT limits.

The FAA proposed to remove§ 23.65(d) since the requirements arecovered in amended § 23.45(h)(2) and incurrent § 23.21.


Section 23.66 Takeoff Climb; One-Engine Inoperative

The FAA proposed a new § 23.66 torequire the determination of the one-

engine-inoperative climb capability ofall WAT limited reciprocating engine-powered and turbine engine-poweredairplanes immediately after takeoff.Since most reciprocating engine-powered airplanes do not haveautofeather, the condition immediatelyafter takeoff can be critical. There is nota minimum climb requirement in thisconfiguration, only the determination ofthe climb or decent gradient. Thisinformation is provided to the pilot inthe AFM (see § 23.1587) to allow thepilot to make informed judgmentsbefore takeoff.


Section 23.67 Climb: One EngineInoperative

The FAA proposed to reorganize§ 23.67 for harmonization with the JAR;to require WAT limits for someairplanes; to require wings level climbup to 400 feet for commuter categoryairplanes; and to make minor changes inairplane configuration requirements.

Revised § 23.67(a) specifies the climbrequirements for non-WAT airplaneswith no change in requirements forthose airplanes.

Revised § 23.67(b) specifies climbrequirements for WAT airplanes. WATcriteria are applied for bothreciprocating engine-powered airplanesof more than 6,000 pounds maximumweight and turbine engine-poweredairplanes. (See the discussion under§ 23.45.) Turbine engine-poweredairplanes have been subject to limitedWAT limitations under § 23.67(c),which the FAA proposed to incorporateinto § 23.67(b).

The FAA proposed to change thetakeoff flap position for normal, utility,and acrobatic category reciprocatingengine-powered airplanes of 6,000pounds or less to ‘‘wing flaps retracted’’from ‘‘most favorable position’’(§ 23.67(a)(4)). Wing flaps retracted isthe position most used in certificationand in service for this size of airplane(see new § 23.67 (a)(1)(iv) and (a)(2)(iv)).

The FAA proposed to remove§ 23.67(d) since all climb speeds (bothall-engine and one engine inoperative)are scheduled and the determination ofVY is no longer required.

The FAA proposed to redesignate§ 23.67(e) for commuter categoryairplanes as § 23.67(c) with no change inrequirements except that the takeoffclimb with landing gear extended mustbe conducted with the landing geardoors open. This is a conservativeapproach offered by the JAA to specifya definite gear door configuration and toremove the requirement to determine


performance during the transientcondition of gear doors opening andclosing. The FAA proposed to specify,in § 23.67(c)(1), that the first segmentclimb must be conducted with thewings level and to further specify thatthe climb speed for the segment must beV2 instead of the requirement for a rangeof speeds from VLOF and whatever theapplicant selects at gear retraction. Also,the FAA proposed, in § 23.67(c)(2), torequire conducting the second segmentclimb with wings level, which isappropriate for operational scenarios.

The FAA proposed to revise § 23.67by removing paragraph (e)(1) and bymoving the requirements to § 23.67(c)and § 23.63 (a)(1) and (d).

In proposed § 23.67(c)(3), enrouteclimb, the FAA added a minimum climbspeed to ensure an adequate marginabove stall speed.

The FAA proposed to redesignate§ 23.67(e)(3) as § 23.67(c)(4) and toremove the paragraph heading‘‘Approach’’ and add ‘‘Discontinuedapproach’’ in its place. The FAAproposed to clarify, in new § 23.67(c)(4),that the climb gradients must be met atan altitude of 400 feet above the landingsurface.


Section 23.69 Enroute Climb/DescentThe FAA proposed a new § 23.69 to

require the determination of all engineand one-engine-inoperative climb/descent rates and gradients in theenroute configuration under alloperational WAT conditions. Thisinformation is necessary for enrouteflight planning and dispatch. Climbspeeds are specified to provide a marginabove VS1.


Section 23.71 Glide: Single-EngineAirplanes

The FAA proposed a new § 23.71 torequire the determination of glidedistance and speed for single-engineairplanes. The information is necessaryfor flight planning and to provide thepilot with information from which tomake informed decisions.


Section 23.73 Reference LandingApproach Speed

The FAA proposed a new § 23.73 todefine the reference landing approachspeeds, VREF. Establishing a definitionfor these speeds simplifies the use of

VREF in other portions of the rule. TheVREF speeds for the various categoryairplanes are established as not less than1.3 VS0. Also, the established speedsconsider the appropriate relationship toVMC determined under § 23.149.


Section 23.75 Landing DistanceThe FAA proposed to revise the

heading, reorganize § 23.75 forharmonization with the JAR, add thelanding reference speed, VREF, andmove the portion on brake pressure to§ 23.735, Brakes.

The FAA proposed to remove thereference to the AFM from theintroductory paragraph. Part 23, subpartB, is generally used to specify flight testrequirements, and part 23, subpart G, isgenerally used to specify the AFMrequirements. The FAA also proposed torevise the introductory paragraph torequire landing distances to bedetermined at standard temperature foreach weight and altitude. Serviceexperience has shown that landingdistances are not sensitive totemperatures. The use of standardtemperature is consistent with WATrequirements. The FAA proposed toremove from the introductory paragraphthe reference to ‘‘approximately 3knots’’ for seaplanes and amphibiansbecause this information is consideredadvisory material on acceptablemethods of compliance.

The FAA proposed to revise § 23.75(a)to add VREF and to require its use. (See§ 23.73.)

The FAA proposed to remove§ 23.75(b) because § 23.45 specifiesthese general requirements. New§ 23.75(b) clarifies that a constantconfiguration must be maintainedthroughout the maneuver.

The FAA proposed to revise§ 23.75(d) by adding the requirement tospecify the weight that must beconsidered for the transition to thebalked landing conditions. Thisrequirement reflects current industrypractice.

The FAA proposed new § 23.75(e) asa general requirement to ensure thereliability of the brakes and tires.

The FAA proposed to revise § 23.75(f)to remove the first use of the word‘‘means’’ and to add the phrase‘‘retardation means’’ in its place, and toremove paragraph (f)(3). Paragraph (f)(3)required that no more than average skillshall be required to control the airplane.This topic is covered in § 23.45(f).

The FAA proposed to remove§ 23.75(h) because the introductoryparagraph of § 23.75 contains commuter

category requirements and § 23.1587requires landing distance correctionfactors.


Section 23.77 Balked LandingThe FAA proposed to revise this

section to include additional WATrequirements and to make editorialchanges.

The proposed revisions to § 23.77 (a)and (b) differentiate between WAT andnon-WAT. (See § 23.45.) Section23.77(a)(4) adds a new climb speedrequirement to ensure that accelerationis not necessary during the transitionfrom landing to balked landing. Theclimb gradient of § 23.77(b) was selectedto be slightly less than the non-WATairplane sea level requirement inexchange for a balked landing climbcapability at all altitudes andtemperatures.

The commuter category climbgradient of 3.3 percent specified in§ 23.77(c) changes to 3.2 percent forconsistency with part 25. Additionaleditorial changes and deletions aremade in § 23.77(c) because the generalrequirements are covered in final§ 23.45.


Section 23.143 GeneralThe FAA proposed to revise

§ 23.143(a) to add the phrase ‘‘during allflight phases’’ to the introductoryparagraph and to add ‘‘Go-around’’ tothe list of flight phases.

The JAA and FAA decided, duringFAA/JAA Harmonization meetings, thatthe term ‘‘go-around’’ included the allengine balked landings of § 23.77,various all engine and one-engine-inoperative aborted landings specifiedin the AFM, and the commuter categorydiscontinued approach of § 23.67(c)(4).Balked landing refers only to the allengine balked landing of § 23.77.

The FAA proposed to revise the two-hand roll force in the table of paragraph(c) from 60 to 50 pounds, to beconsistent with JAR 25. The FAA alsoproposed to revise the table to show aone-hand on the rim roll force of 25pounds. This is an FAA/JAAharmonized value.

Comment: Raytheon AircraftCompany comments that the controlforce limits table is specifically tied tothe flight phases of paragraph (a) andthat this ‘‘could be interpreted asproviding an upper limit ofmaneuvering force (stick force per g)such that all normal operational


maneuvers would have to be performedwithin a pitch force limit of 75 lbs(wheel, two hands), for unspecifiednormal acceleration limits.’’

Raytheon states that this has not beenprevious policy and could become acostly requirement for larger part 23aircraft with large cg ranges, ‘‘ifsubstantial normal accelerationexcursions are considered ‘normal’maneuvering.’’ Raytheon recommends‘‘that either the normal accelerationexcursions be defined for normal,utility, acrobatic, and commutercategories or the explicit tie to the flightphases in this rule be deleted.’’

FAA Response: Raytheon’s concern iswhether ‘‘normal accelerationexcursions are considered ‘normal’maneuvering.’’ They are not.

Section 23.143 has historically beentitled ‘‘General’’ and has always beenconsidered broad enough to covercontrollability and maneuverability ingeneral. The inclusion of ‘‘all flightphases’’ is considered clarifying, andRaytheon’s concern that the concept ofnormal being expanded is unwarranted.Adopting this proposal would notchange current certification practice.

The proposals are adopted asproposed.

Section 23.145 Longitudinal ControlThe FAA proposed to revise § 23.145

to change the speed ranges applicable tothe takeoff, enroute, and landingconfigurations.

Editorial changes were also proposedfor the introductory text of paragraph (b)with no substantive change.

The FAA proposed in paragraph (b)(2)to change the requirement from‘‘attaining and maintaining, as aminimum, the speed used to showcompliance with § 23.77’’ to ‘‘allow theairspeed to transition from 1.3 VS0 to 1.3VS1.’’

The FAA also proposed to redesignateparagraphs (b)(2) (i) and (ii) as (b)(2) and(b)(3), respectively, and in paragraph(b)(3) to add more specific requirementsif gated flap positions are used.

The FAA proposed to change thespeed reference from 1.4 VS0 to VREF forlanding configuration in paragraph(b)(5). The FAA also proposed inparagraph (b)(5) to allow a two-handedcontrol force since use of two hands isconsidered appropriate for a power offcondition because the pilot does notneed to change power settings.

Proposed paragraph (b)(6) is the sameas former paragraph (b)(3).

In paragraph (c), the FAA proposed tochange the speed range for maneuveringcapability from ‘‘above VMO/MMO andup to VD/MD’’ to ‘‘above VMO/MMO andup to the maximum speed shown under

§ 23.251.’’ This change is considerednecessary because a range of speeds canbe chosen as VD/MD, and reference to§ 23.251 ensures a flight demonstratedspeed instead of a design speed.

The FAA proposed in paragraph (d) tochange the speed that must bemaintained for power-off glide from 1.3VS0 to VREF.


Section 23.147 Directional and LateralControl

The FAA proposed to make minorrevisions to § 23.147(a) and to add twonew requirements in proposedparagraphs (b) and (c). The flapsretracted configuration for § 23.147(a)(4)are consistent with proposed § 23.67.

In proposed § 23.147(b), the FAAproposed to add requirements formultiengine airplanes that, during anenroute climb, when an engine fails theairplane maintains a minimum standardof controllability after allowing for apilot action delay of two seconds. Thisproposed change tests for a likelyoperational scenario and is intended toensure satisfactory controllability.

In § 23.147(c), the FAA proposed totest for the failure or disconnection ofthe primary lateral control. Thisparagraph requires that the airplaneexhibit adequate dihedral effectthroughout the airplane’s operationalenvelope to ensure continued safe flightand landings if a lateral controldisconnects. In addition, thisrequirement complements the relaxedrequirements of proposed § 23.177(b)(see proposal for § 23.177).

Comment: Raytheon comments thatthere is no basis provided for the newrules proposed in § 23.147 (b) and (c).Raytheon states that the ‘‘two seconddelay and the 45 degree bank appear tobe arbitrary choices’’ and that there ‘‘isno comparable FAR requirement.’’

FAA Response: The values of 2seconds and 45 degrees in proposedparagraph (b) were determined from§ 23.367, ‘‘Unsymmetrical loads due toengine failure,’’ which contains a 2second delay for pilot corrective action.Historically, the 2 second delay and the45 degree bank angle correlate to asimilar requirement used for years bythe United Kingdom CAA.

Proposed paragraph (c), failure of thelateral control, is part of a reduction inthe overall lateral stability requirements.In Amendment 23–45, the FAA reducedthe power requirements for § 23.177(a)in the landing configuration from 75percent maximum continuous power tothe power required to maintain a threedegree angle of descent. The § 23.177

requirement essentially demonstratedthat the airplane had the wing dihedraleffect and rudder control power to raisea low (banked) wing using rudder only.Prior to this amendment, manymanufacturers had to install an aileron/rudder interconnect to meet thisrequirement because of the high powersetting. An aileron/rudder interconnectis a mechanism that ties the twocontrols together such that when onecontrol surface deflects, the other willalso deflect. In the case of § 23.177, thepilot uses the rudder, which alsodeflects the aileron and raises the wingto level. The underlying intent of thisrule is to demonstrate that the airplaneis controllable after an aileron controlfailure, similar to the elevator controlfailure demonstration currently in therequirements. This change, inconjunction with Amendment 23–45,will allow manufacturers to eliminatethe need for the aileron/rudderinterconnect.


Section 23.149 Minimum ControlSpeed

The FAA proposed to clarify § 23.149,to add a VMC in the landingconfiguration, and to provide theprocedure for determining a groundVMC.

The FAA proposed to clarify§ 23.149(a), with no requirementchange. The FAA also proposed toclarify § 23.149(b) and to remove thereference to lesser weights in paragraph(b)(4) because the range of weights iscovered in § 23.21.

The FAA proposed to revise§ 23.149(c) to specify the requirementsfor a VMC in the landing configurationfor all WAT airplanes. This requirementis necessary for WAT airplanes toprovide a VREF margin above the VMC

determined in the landingconfiguration. (See proposal for § 23.73.)

The FAA proposed a new § 23.149(f)to contain requirements to determine aVMCG for commuter category airplanesthat could, at the option of theapplicant, be used to comply with§ 23.51. (See § 23.51.)

The only comment came from theJAA, which addressed a knowndisharmony, VSSE, from a previous rulechange.


Section 23.153 Control DuringLandings

The FAA proposed to revise § 23.153to reference landing speeds to VREF andto reorganize the section.



Section 23.155 Elevator Control Forcesin Maneuvers

The FAA proposed to revise § 23.155to make changes to the powerrequirements and gradient of the stickforce curve.

The FAA proposed to revise§ 23.155(b) to specify the maximumcontinuous power for the test requiredby this section instead of allowing apower selected by the applicant as anoperating limitation. This revisioneliminates an unnecessary powerspecification and simplifies normaloperations for the pilot.

The FAA proposed to revise§ 23.155(c) to address stick forcegradient to ensure that stick forcelightening is not excessive. As stated inthe preamble to Notice 94–22, the FAAwill issue advisory material onacceptable methods of compliance.

Comment: Raytheon states thatproposed paragraph (c) adds a newrequirement that there must not be an‘‘excessive decrease’’ in the gradient ofthe stick force per g with increasing loadfactor. Raytheon’s concern is that this isa very loosely defined requirement andthat the allowable decrease inmaneuvering stability may be a functionof aircraft size and mission.

FAA Response: The FAA agrees thatevery airplane is different and that,therefore, each must be consideredseparately. The FAA does not agree thatparagraph (c) is loosely defined. Formany of the flight requirements,including ‘‘excessive decrease,’’ theFAA must evaluate the individualairplanes to determine if the handlingqualities are safe.

This proposal are adopted asproposed.

Section 23.157 Rate of Roll

The FAA proposed to revise§ 23.157(d) power and trimrequirements and to clarify the flapposition. In § 23.157(d)(1), the FAAproposed to clarify that the flaps shouldbe in the landing position and§ 23.157(d)(3) makes the powerconsistent with the approachconfiguration, which is theconfiguration being tested. The FAAproposed in § 23.157(d)(4) to relate thetrim speed to VREF. (See amendment for§ 23.73.)


Section 23.161 Trim

The FAA proposed to revise § 23.161power, configurations, and speeds.

The FAA proposed to revise§ 23.161(a) to state the safety principlesunderlying the trim requirements and toprovide a regulatory requirement forconsidering conditions that might beencountered outside the requirementsaddressed in paragraphs (b) through (d).

The FAA proposed to revise§ 23.161(b)(1) to add a requirement totrim at MMO in addition to VMO toclarify that the airplane must trim in theMach limited speed range.

The FAA proposed to revise§ 23.161(b)(2) to require lateral anddirectional trim over a range of 1.4 VS1

to VH or VMO/MMO for commutercategory airplanes instead of only thehigh speed requirement in the presentrules.

The FAA proposed, in theintroductory paragraph of § 23.161(c), toremove the reference to VMO/MMO

because it is covered in the applicableindividual sections. In § 23.161(c)(1),the FAA proposed to require trim attakeoff power, as this is a likelyoperational scenario for most airplanesand the condition should be tested. Inaddition, the change relates themaximum continuous power climbspeeds and configuration to § 23.69, theenroute climb requirement. The FAAproposed to redesignate § 23.161(c)(2) as§ 23.161(c)(4), to change the referenceVREF for a landing speed, and to add arequirement for the airplane to trim atthe steepest landing approach gradientthe applicant chooses under § 23.75.The FAA proposed to redesignate§ 23.161(c)(3) as § 23.161(c)(2) witheditorial changes and to redesignate§ 23.161(c)(4) as § 23.161(c)(3) with anincrease in the trim speed from 0.9 VNO

or VMO to VNO or VMO/MMO. Theincrease in trim speed is appropriatebecause descent is permitted and iscommon at VMO.

In § 23.161(d), the FAA proposed tomake editorial changes in theintroductory paragraph, to reference theappropriate § 23.67 requirements, and toremove commuter category speedranges, which are moved to the new§ 23.161(e). The FAA proposed to revise§ 23.161(d)(4) to specify flaps retractedinstead of referencing the § 23.67configurations. Flaps retracted is thelikely sustained configuration where apilot would need to trim. Also, the flapsretracted configuration for § 23.161(d)(4)is consistent with § 23.67.

The FAA proposed a new § 23.161(e)to ensure that excessive forces are notencountered in commuter categoryairplanes during extended climbs at V2

in the takeoff configuration, when climbabove 400 feet is required.


Section 23.175 Demonstration of StaticLongitudinal Stability

The FAA proposed to revise§ 23.175(a)(1) to change the flap positionfrom the climb position to the flapsretracted position. This is a clarifyingchange since virtually all part 23airplanes use the flaps retracted positionfor climb. Also, this change aligns thepart 23 and part 25 climb staticlongitudinal stability requirements.

The FAA proposed, in § 23.175(a)(3),to remove the option for the applicantto select some power other thanmaximum continuous power as anoperating limitation. As noted in thediscussion of § 23.155, this eliminates apower specification that is unnecessaryand simplifies normal operations for thepilot. In § 23.175(a)(4), the FAAproposed to make the trim speedconsistent with the enroute all-engineclimb speed.

The FAA proposed in § 23.175(b) torearrange the paragraph with no changein requirements. The definition of VFC/MMC contained in § 23.175(b)(2) ismoved to part 1, to harmonize with JAR1. (See the change to § 1.1.)

The FAA proposed to remove§ 23.175(c). The test for gear downcruise static longitudinal stabilityrequired under paragraph (c) isconsidered superfluous to the landingconfiguration static longitudinalstability test and does not represent alikely operating scenario.

The FAA proposed to redesignate§ 23.175(d) as § 23.175(c) with a changeto VREF as the trim speed.


Section 23.177 Static Directional andLateral Stability

The FAA proposed to revise § 23.177to remove the requirements for two-control airplanes, to make minorclarifying changes, and to specify anexclusion for acrobatic categoryairplanes.

The FAA proposed in § 23.177 toremove the introductory phraseconcerning three-control airplanes,which is consistent with the removal ofthe requirements for two-controlairplanes in paragraph (b). The two-control airplane regulations wereintroduced in 1945 but no two-controlairplanes have been certificated forseveral decades and no need is foreseenfor these regulations. If an applicant


proposes a two-control airplane, theFAA would issue special conditions.

The FAA proposed that, afterremoving the introductory portion of§ 23.177(a), paragraph (a)(1) would beredesignated as (a). In the first sentence,‘‘skid’’ is replaced with ‘‘wings levelsideslip’’ to clarify the intendedmaneuver. Also, this change increasesthe power requirement fordemonstration of directional stability inthe landing configuration. Therequirement specifies power necessaryto maintain a three degree angle ofdescent. Maximum continuous power isconsidered appropriate since directionalstability should be maintained during abalked landing, particularly sincedirectional instability is an undesirablecharacteristic at any point in the flightenvelope. Also, the FAA proposed toreplace VA with VO to be consistent with§ 23.1507.

The FAA proposed, in § 23.177(b), toreplace ‘‘any’’ with ‘‘all’’ in the firstsentence to clarify that all landing gearand flap positions must be addressed.Also, the FAA proposed that theparagraph specify a minimum speed atwhich static lateral stability may not benegative, as 1.3 VS, for all configurationsexcept takeoff. This is consistent withthe other speeds specified in § 23.177(b)and relieves the requirement for otherthan takeoff speeds.

The FAA proposed new § 23.177(c) toprovide an exclusion for the dihedraleffect for acrobatic category airplanesapproved for inverted flight. Thischange recognizes that, in full acrobaticairplanes, the dihedral effect is not adesired characteristic

The addition of § 23.147(c), whichensures lateral control capabilitywithout the use of the primary lateralcontrol system, compensates for therelieving nature of proposed § 23.177(b)and the exception from therequirements of § 23.177(b) for acrobaticcategory airplanes.

The FAA proposes to redesignate§ 23.177(a)(3) as § 23.177(d) and toremove the next to the last sentence of§ 23.177(d), concerning bank angle andheading. The requirement is not anecessary test condition and a constantheading during the sideslip may beimpossible in some airplanes.

Comment: Raytheon commented onthe requirements for stability in steadyheading slips, which were changed in aprevious amendment (Amendment 23–21; 43 FR 2318; January 16, 1978), andrecommended clarifying language.

FAA Response: As Raytheon noted,the rule language they believe needsclarification was not addressed inNotice 94–22, and, therefore, is beyondthe scope of this rulemaking.


Section 23.201 Wings Level StallThe FAA proposed to remove the two-

control airplane requirements, altitudeloss requirements, and to makeclarifying changes in § 23.201.

The FAA proposed to revise§ 23.201(a) to remove the applicabilityreference for an airplane withindependently controlled roll anddirectional controls and to replace thelast word ‘‘pitches’’ with ‘‘stalls’’ sincestalls may be defined by other thannose-down pitching.

The FAA proposed to remove§ 23.201(b) since it applies to two-control airplanes. (See § 23.177 fordiscussion of two-control airplanerequirements.)

The FAA proposed to divide§ 23.201(c) into § 23.201(b), stallrecognition, and § 23.201(c), stallrecovery. The FAA proposed, in§ 23.201(b), to clarify that the testshould start from a speed at least 10knots above the stall speed, with nochange in requirements. The FAAproposed to add § 23.201(c) to specifyhow long the control must be heldagainst the stop. This change ensuresthat the procedure for determining stallspeed is the same procedure used to teststall characteristics. The FAA proposedto remove the last sentence of paragraph(c) on the increase of power because itonly applies to altitude loss.

The FAA proposed to remove§ 23.201(d), as suggested by the JAA,since the determination of altitude loss,and its subsequent furnishing in theAFM, is not considered informationuseful to the pilot for safe operation ofthe airplane.

The FAA proposed new § 23.201(d)based on present § 23.201(e), to clarifythat the roll and yaw limits applyduring both entry and recovery.

The FAA proposed new § 23.201(e)based on former paragraph (f) with somerevisions. During FAA/JAAharmonization meetings, the JAApointed out to the FAA that, in highpower-to-weight ratio airplanes, extremenose-up attitudes were the principalcriteria for use of reduced power, notthe presence of undesirable stallcharacteristics. The FAA concurs, and,therefore, proposed to remove thephrase concerning stall characteristics.


Section 23.203 Turning Flight andAccelerated Turning Stalls

The FAA proposed to revise § 23.203to add the word ‘‘turning’’ before

‘‘stalls’’ and after ‘‘accelerated’’ in theheading, the introductory text, and inparagraphs (a)(2) and (b)(5). This changeclarifies that accelerated stalls areperformed in turning flight. Thisclarification reflects current practice.

In § 23.203 (a) and (b), the FAAproposed to reference the stalldefinition in current § 23.201(b), whichis more specific than the present generalwords ‘‘when the stall has fullydeveloped or the elevator has reachedits stop.’’

For clarification, the FAA proposedthat paragraph (b)(4) be separated intoparagraphs (b)(4) and (b)(5) withoutsubstantive change, and that formerparagraph (b)(5) be redesignated asparagraph (b)(6).

The FAA proposed in § 23.203(c)(1) toclarify the wing flap positions bychanging ‘‘each intermediate position’’to ‘‘each intermediate normal operatingposition,’’ and in § 23.203(c)(4) to clarifythe use of reduced power. (See the finalchange to § 23.201(f).)

The FAA proposed new paragraph(c)(6) to be consistent with new§ 23.207(c)(6) configurations(Amendment No. 23–45).


Section 23.205 Critical Engine-Inoperative Stalls

The FAA proposed to remove§ 23.205. The stall demonstrationconditions are not realistic because theengine operation and power asymmetrydo not represent conditions likely toaccompany an inadvertent stall inservice. Service history shows, however,that stalls with significant powerasymmetry can result in a spin, even onairplanes that are certificated to thepresent requirement. Based on thisservice history, the FAA determinedthat the requirement for demonstratingone-engine-inoperative stalls is noteffective in ensuring that inadvertentstalls with one engine inoperative willhave satisfactory characteristics and berecoverable. Sufficient protectionagainst the hazard of stalling with oneengine inoperative is provided by theone-engine-inoperative performancerequirements and operating speedmargins, coupled with the requirementsfor determination of VMC, and theaddition of a directional and lateralcontrol test under § 23.147(b).

No comments were received on theproposal for this section, and the sectionis removed as proposed.

Section 23.207 Stall WarningThe FAA proposed, in § 23.207(c), to

reference the stall tests required by


§ 23.201(b) and § 23.203(a)(1) and tospecify that during such tests for oneknot per second deceleration stalls, bothwings level and turning, the stallwarning must begin at a speedexceeding the stalling speed by a marginof not less than 5 knots. The FAAproposed to remove the quantifiedupper limit in the rule of 10 knots or 15percent of the stalling speed. The upperlimit has created problems formanufacturers because of the complexdesign features required to showcompliance. The upper limitrequirement is, in effect, replaced by thenuisance stall warning provision in§ 23.207(d).

The FAA proposed to divide§ 23.207(d) into § 23.207 (d) and (e),with § 23.207(d) on nuisance stallwarnings having no change inrequirements. In § 23.207(e), the FAAproposed to remove the bottom limit offive knots for decelerations greater thanone knot per second and to specify thatthe stall warning must begin sufficientlybefore the stall so that the pilot can takecorrective action. This is consideredappropriate because, at the higherdeceleration rates of three to five knotsper second, a specified five knots maynot be enough stall warning.

The FAA proposed new § 23.207(f) toallow for a mutable stall warning systemin acrobatic category airplanes, withautomatic arming for takeoff andrearming for landing. This featureallows the pilot to disengage thewarning during acrobatics whileretaining the safety feature duringtakeoff and landing.


Section 23.221 SpinningThe FAA proposed to change the

point to start the one-turn-spin recoverycount, to delete the ‘‘characteristicallyincapable of spinning’’ option, and tomake minor changes in acrobaticcategory spins in § 23.221.

The FAA proposed, in § 23.221(a), toreplace the exception for airplanescharacteristically incapable of spinningwith an exception for airplanes thatdemonstrate compliance with theoptional spin resistant requirements ofparagraph (a)(2) of this section. Criteriafor an airplane incapable of spinning areunnecessary since criteria for spinresistant airplanes are provided. Asproposed, § 23.221(a) changed the pointat which the count for the one-turn-spinrecovery begins. The change provides aspecific point to begin the count byreplacing the phrase ‘‘after the controlshave been applied’’ with ‘‘afterinitiation of the first control action for

recovery.’’ Under the former rules, if anapplicant proposed a multiple steprecovery procedure that starts with therudder, then the airplane may beeffectively recovered before the start ofthe recovery count.

The FAA proposed, in§ 23.221(a)(1)(ii), to specify that nocontrol force or characteristic canadversely affect prompt recovery. Thiswould be an improvement over thepresent requirement because it includesyaw and roll as well as pitch control.

The FAA proposed to recodify§ 23.221(a)(1) into § 23.221 (a)(1)(i)through (a)(1)(iv) with no changes in therequirements, and to restate§ 23.221(a)(2) on spin resistant airplaneswith minor editorial changes but withno change in requirements.

The FAA proposed to specify, in§ 23,221(b), the emergency egressrequirements of § 23.807(b)(5) for thoseutility category airplanes approved forspinning, thereby cross-referencing therequirements of § 23.807 to the flightrequirements.

The FAA proposed, in theintroductory paragraph of § 23.221(c), torequire acrobatic category airplanes tomeet the one-turn-spin requirements of§ 23.221(a). This change is neededbecause acrobatic category airplanesshould have sufficient controllability torecover from the developing one-turn-spin under the same conditions asnormal category airplanes. Theintroductory paragraph also cross-references § 23.807 for emergency egressrequirements.

The FAA proposed, in § 23.221(c)(1),pertaining to acrobatic categoryairplanes, to add a requirement for spinrecovery after six turns or any greaternumber of turns for which certificationis requested. This rule requires recoverywithin 1.5 turns after initiation of thefirst control action for recovery. Thisrequirement ensures recovery within 1.5turns if the spin mode changes beyondsix turns. As an alternative, theapplicant may stop at six turns andprovide a limitation of six turns.

The FAA proposed, in § 23.221(c)(2),to remove the option to retract flapsduring recovery and to provide theapplicant with a choice of flaps up orflaps deployed for spin approval. Theparagraph continues to prohibitexceeding applicable airspeed limitsand limit maneuvering load factors.

The FAA proposed new § 23.221(c)(4)to ensure that the acrobatic spins do notcause pilot incapacitation.

The FAA proposed to remove§ 23.221(d), relating to airplanes that are‘‘characteristically incapable ofspinning,’’ which has been in theregulation since at least 1937. In 1942,

the present weight, center of gravity,and control mis-rig criteria wereintroduced into Civil Air Regulation(CAR) 03. Since then, the NationalAeronautics and Space Administration(NASA) spin resistant requirements,which are based on research, have beendeveloped and incorporated in theregulations by Amendment No. 23–42(56 FR 344, January 3, 1991). If anapplicant proposes a non-spinableairplane, it would be appropriate toapply the requirements of § 23.221(a)(2)as proposed in Notice 90–22.

The only comment on this sectionwas a JAA statement recognizing this asan existing disharmony.


Section 23.233 Directional Stabilityand Control

The FAA proposed to make minorword changes to § 23.233(a) toharmonize this section with thecorresponding JAR section.


Section 23.235 Operation on UnpavedSurfaces

The FAA proposed to revise theheading of § 23.235 and to remove wateroperating requirements, which aremoved to new § 23.237.

No comments were received on theproposals for this section, and it isadopted as proposed.

Section 23.237 Operation on Water

New § 23.237, for operation on water,is the same as the former § 23.235(b).

The only comment on this section isa JAA statement acknowledging anexisting disharmony.


Section 23.253 High SpeedCharacteristics

The FAA proposed to removeparagraph (b)(1), since the requirementfor piloting strength and skill is coveredin § 23.141.


Section 23.562 Emergency LandingDynamic Conditions

The FAA proposed to change the oneengine inoperative climb to remove thereference in § 23.562(d) and to add it to§ 23.67(a)(1).

The only comment on this section isa JAA statement acknowledging existingdisharmony.



Section 23.1325 Static PressureSystem

The FAA proposed to revise§ 23.1325(e) to clarify that the staticpressure calibration must be conductedin flight, which is standard practice, andto remove and reserve § 23.1325(f).


Section 23.1511 Flap Extended SpeedThe FAA proposed to remove from

§ 23.1511(a) references to § 23.457.Section 23.457 is proposed to beremoved in a related NPRM, Notice No.94–20 (59 FR 35196, July 8, 1994), onthe airframe.


Section 23.1521 PowerplantLimitations

The FAA proposed to amend§ 23.1521 to require maximumtemperature be established for takeoffoperation and to require an ambienttemperature limit for reciprocatingengines in airplanes of more than 6,000pounds.

The FAA proposed in § 23.1521(b)(5)to require the establishment ofmaximum cylinder head, liquid coolant,and oil temperature limits for takeoffoperation without regard to theallowable time. Previously, temperaturelimits were required only if the takeoffpower operation is permitted for morethan two minutes. It is appropriate torequire operating temperaturelimitations because most takeoffoperations will exceed two minutes.

The FAA proposed in § 23.1521(e) torequire an ambient temperature limit forturbine engine-powered airplanes andreciprocating engine-powered airplanesover 6,000 pounds. These airplanes aresubject to WAT limits and the revisionwill ensure that airplane engines willcool at the ambient temperature limit.


Section 23.1543 Instrument Markings:General

The FAA proposed new § 23.1543(c)to require that all related instruments becalibrated in compatible units. This isconsidered essential for safe operation.


Section 23.1545 Airspeed IndicatorThe FAA proposed in § 23.1545(b)(5)

to delete any one-engine-inoperativebest rate of climb speed marking

requirements for WAT limitedairplanes. These airplanes already havescheduled speeds in case of an enginefailure. The FAA proposed thatparagraph (b)(5) apply only to non-WATairplanes for which the one-engine-operative best rate of climb speedmarking has been simplified to reflectperformance for sea level at maximumweight. Since the blue arc rule waspromulgated in Amendment No. 23–23(43 FR 50593, October 30, 1978),certification experience has shown thatthe marking of an arc is unnecessarilycomplicated. For many airplanes, theapproved arc was so narrow that the arcwas a line; therefore, final paragraph(b)(5) requires a blue radial line insteadof an arc.

The FAA proposed to revise§ 23.1545(b)(6) to retain the existingVMC requirement for non-WATairplanes and to remove the requirementfor VMC markings for WAT airplanessince WAT airplanes already havescheduled speeds in case of enginefailure.


Section 23.1553 Fuel QuantityIndicator

The FAA proposed to remove, from§ 23.1553, the use of an arc to show aquantity of unusable fuel. The FAAproposed that the rule reference theunusable fuel determination and requireonly a red radial line, which provides aclearer indication of fuel quantity forpilots.


Section 23.1555 Control MarkingsThe FAA proposed to add to

§ 23.1555(e)(2) a requirement that nocontrols except emergency controls bered.

Comment: Transport Canada statesthat certain cockpit controls serve a dualpurpose in that they serve normalaircraft operation functions as well asemergency functions. Examples are fuelselector valves and door handles.Transport Canada recommends rulelanguage that recognizes dual usage.

FAA Response: Transport Canada’sstatement about the existence of dualusage controls is correct. The FAAoriginally intended to address the dualusage issue in an AC. On furtherevaluation of the proposed rulelanguage, dual usage controls would beprohibited, if it were adopted asproposed. Therefore, an AC could not beused to allow controls such as themixture (which is usually red) to

continue to be red without violating therule. The FAA has incorporated the dualusage language in the final rule to avoidconfusion between the intent of the ruleand the current practice.

The proposal is adopted with thechanges mentioned above.

Section 23.1559 Operating LimitationsPlacard

The FAA proposed to simplify§ 23.1559 and to remove duplicatematerial while requiring essentially thesame information. Most airplanescurrently operate with an AFM and thenew rule places emphasis on using theAFM to define required operatinglimitations.


Section 23.1563 Airspeed Placards

The FAA proposed to add a newparagraph (c) to § 23.1563. The newparagraph is applicable to WAT limitedairplanes and requires providing themaximum VMC in the takeoffconfiguration determined under§ 23.149(b). This is desirable since theVMC is not marked on the airspeedindicator for these airplanes.


Section 23.1567 Flight ManeuverPlacard

The FAA proposed to add new§ 23.1567(d) to apply to acrobatic andutility airplanes approved forintentional spinning, which requires aplacard listing control actions forrecovery. New paragraph (d) proposedto require a statement on the placardthat the airplane be recovered whenspiral characteristics occur, or after sixturns, or at any greater number of turnsfor which certification tests have beenconducted. This paragraph replaces thesimilar placard requirement in current§ 23.1583(e)(3) for acrobatic categoryairplanes.


Section 23.1581 General

The FAA proposed to make editorialchanges in § 23.1581 that recognizeWAT limited and non-WAT limitedairplanes.

In new § 23.1581(a)(3), the FAAproposed to require informationnecessary to comply with relevantoperating rules. This is a FAR and JARharmonization item and is considerednecessary because some operationalrules, such as § 135.391, require flight


planning with one-engine-inoperativecruise speed and/or driftdown data. Forairplanes operated under part 135 in theUnited States, it represents no change inrequirements.

The FAA proposed § 23.1581(b)(2) torequire that only WAT limited airplaneAFM’s provide data necessary fordetermining WAT limits.

The FAA proposed new § 23.1581(c)to require the AFM units to be the sameas on the instruments.

The FAA proposed new § 23.1581(d)to remove the requirement for a table ofcontents. This is considered a formatrequirement and is not appropriate forthis section, which specifies AFMcontent. Section 23.1581(d) is replacedby a requirement to present alloperational airspeeds as indicatedairspeeds. This adopts current practice.


Section 23.1583 Operating LimitationsThe FAA proposed to revise § 23.1583

operating limitations information for theAFM. The FAA proposed to reviseairspeed limitations for commutercategory airplanes, to require AFMlimitations for WAT limited airplanes,to furnish ambient temperaturelimitations and smoking restrictioninformation, and to specify types ofrunway surfaces.

The FAA proposed, in § 23.1583(a)(3),to make VMO/MMO airspeed operatinglimitations applicable only to turbinepowered commuter category airplanes.This is consistent with current practicesince no reciprocating engine-poweredcommuter category airplanes have beenproposed.

In § 23.1583(c)(3), the FAA proposedto add takeoff and landing weightlimitations for WAT limited airplanes.(See § 23.45.)

The FAA proposed to revise§ 23.1583(c)(4) and (c)(5), to renumber§ 23.1583(c)(3) and (c)(4), and to makeeditorial and cross-reference changes. Inparagraph (c)(4)(ii), the FAA proposed anew requirement that the AFM includethe maximum takeoff weight for eachairport altitude and ambienttemperature within the range selectedby the applicant at which the accelerate-stop distance determined under § 23.55is equal to the available runway lengthplus the length of any stopway, ifavailable. This is currently required fortransport category airplanes and isnecessary for harmonization with JAR23.

In § 23.1583(c)(6), the FAA proposedto establish the zero wing fuel weight of§ 23.343 as a limitation. This providesthe pilot with information necessary to

prevent exceeding airplane structurallimits.

The FAA proposed editorial changesto § 23.1583(d) and, in paragraphs (e)(1)and (e)(2), to remove references to‘‘characteristically incapable ofspinning.’’ As discussed under § 23.221,requirements for ‘‘characteristicallyincapable of spinning’’ are removed.

In § 23.1583(e)(4), the FAA proposedto add a requirement to specifylimitations associated with spirals, sixturn spins, or more than six turn spins.The requirement for a placard isremoved since the requirement iscovered in § 23.1567.

The FAA proposed to revise§ 23.1583(e)(5) based on formerparagraph (e)(4) for commuter categoryairplanes. This restates the maneuversas those proposed for commutercategory airplanes in § 23.3.

The FAA proposed to revise theheading of § 23.1583(f) and to add alimit negative load factor for acrobaticcategory airplanes.

The FAA proposed to revise§ 23.1583(g) to make editorial changeswith no change in requirements and toreference the flight crews’ requirementsin § 23.1523. As proposed, § 23.1583(k),(l), and (m) are redesignated as§ 23.1583(i), (j), and (k).

The FAA proposed new § 23.1583(l)to require baggage and cargo loadinglimits in the AFM.

The FAA proposed a new§ 23.1583(m) to require any speciallimitations on systems and equipmentin the AFM. This provides the pilotwith information necessary for safeoperation of the airplane systems andequipment.

The FAA proposed a new § 23.1583(n)to require a statement on ambienttemperature limitations. Maximumcooling temperature limits have beenrequired for turbine powered airplanesby § 23.1521(e); however, therequirement for the limitation has neverbeen specified in § 23.1583. Proposed§ 23.1583(n) requires both maximumand minimum temperature limits ifappropriate. A minimum temperaturelimit provides the pilot withinformation necessary to avoid airplanedamage during low temperatureoperations.

The FAA proposed a new § 23.1583(o)to state any occupant smokinglimitations on the airplane in the AFM.

The FAA proposed a new § 23.1583(p)to require the applicant to state whatrunway surfaces have been approved.

No comments were received on theproposals for this section, and it isadopted as proposed.

Section 23.1585 Operating Procedures

The FAA proposed to rearrange thematerial in § 23.1585(a). Also, the FAAproposed to add, for all airplanes, arequirement to paragraph (a) thatinformation in the following areas beincluded: Unusual flight or groundhandling characteristics; maximumdemonstrated values of crosswinds;recommended speed for flight in roughair; restarting an engine in flight; andmaking a normal approach and landingin accordance with §§ 23.73 and 23.75.All of these requirements are in former§ 23.1585(a) except for restarting aturbine engine in flight, which is informer paragraph (c)(5) pertaining onlyto multiengine airplanes. The FAAdecided that a restart capability is notrequired for single reciprocating engineairplanes for the reasons given in thepreamble discussion of proposal 3 inAmendment No. 23–43 (58 FR 18958,April 9, 1993). The requirement toprovide restart information shouldapply to single turbine engines,however, since turbine engine designsincorporate a restart capability andinadvertent shutdowns may occur. Therequirement for normal approach andlanding information, in accordance withthe landing requirement in §§ 23.73 and23.75, is new. This information isnecessary to enable pilots to achieve thepublished landing distances and, ifnecessary, to safely transition to abalked landing.

The FAA proposed to revise§ 23.1585(b) by adding newrequirements, which cover gliding afteran engine failure for single-engineairplanes, to reference the newrequirements proposed in § 23.71.

The FAA proposed to revise§ 23.1585(c) to require compliance withparagraph (a) plus the followingrequirements from former paragraph (c):Approach and landing with an engineinoperative; balked landing with anengine inoperative; and VSSE asdetermined in § 23.149. The FAA alsoproposed to redesignate paragraph (c)requirements, information onprocedures for continuing a takeofffollowing an engine failure andcontinuing a climb following an enginefailure, as proposed (e) for normal,utility, and acrobatic multiengines.

The FAA proposed to revise§ 23.1585(d) to apply to normal, utility,and acrobatic airplanes, which wouldhave to comply with paragraph (a) andeither (b) or (c). These airplanes mustalso comply with the normal takeoff,climb, and abandoning a takeoffprocedures, which were contained inparagraph (a).


The FAA proposed to revise§ 23.1585(c), for normal, utility andacrobatic multiengine airplanes, torequire compliance with proposed (a),(c), and (d), plus requirements forcontinuing a takeoff or climb with oneengine inoperative that were in formerparagraph (c) (1) and (2).

The FAA proposed to revise§ 23.1585(f) to amend normal takeoffrequirements in former paragraph (a)(2);to add accelerate-stop requirements; andto continue takeoff after engine failure,which was in former paragraph (c)(1).

The FAA proposed no substantialchanges in § 23.1585 (g) and (h), whichare based on paragraphs (d) and (e),respectively.

The FAA proposed to revise§ 23.1585(i) based on former paragraph(g) on the total quantity of usable fueland to add information on the effect ofpump failure on unusable fuel.

The FAA proposed a new § 23.1585(j)to require procedures for safe operationof the airplanes’ systems and equipmentthat, although not previously required,are current industry practice.

In the proposed revision of§ 23.1585(h), the commuter categoryairplane procedures for restartingturbine engines in flight would nolonger be necessary because therequirement is covered under paragraph(a)(4).

Comment: The JAA comments thatthe JAA does not agree with limiting theinflight engine restart requirements ofproposed paragraph (a)(4) to turbineengines only.

FAA Response: The JAA commentaddresses a known disharmony betweenthe regulations.

No substantive comment wasreceived, and the proposals are adoptedas proposed.

Section 23.1587 PerformanceInformation

The FAA proposed to revise § 23.1587to rearrange existing material, to removeski plane performance exceptions, toremove the option of calculatingapproximate performance, to removestaff altitude loss data, and to requireoverweight landing performance in§ 23.1587. Stalling speed requirementsof paragraph (c)(2) and (3) are combinedand moved to final paragraph (a)(1) andreference and stalling speedrequirement of § 23.49. Information onthe steady rate and gradient of climbwith all engines operating is required byparagraph (a)(2). This is revised fromparagraph (a)(2). The climb sectionreferenced in existing § 23.1587(a)(2) isremoved and replaced with § 23.69(a).

The FAA proposed to reviseparagraph (a)(3) to add that landing

distance determined under § 23.75 mustbe provided for each airport altitude,standard temperature, and type ofsurface for which it is valid. The FAAproposed to revise paragraph (a)(4) torequire information on the effect onlanding distance when landing on otherthan hard surface, as determined under§ 23.45(g). The FAA proposed to reviseparagraph (a)(5) to cover information onthe effects on landing distance ofrunway slope and wind. This providesthe pilot with data with which toaccount for these factors in his or hertakeoff calculations.

The FAA proposed to removerequirements on ski planes from§ 23.1587(b) and to add a requirementfor a steady angle of climb/descent, asdetermined under § 23.77(a), in itsplace. This requirement applies to allnon-WAT airplanes.

The FAA proposed to reviseparagraph (c) to apply normal, utility,and acrobatic category airplanes, ratherthan all airplanes. The FAA proposed toremove the stall altitude lossrequirements from paragraph (c)(1). Asmentioned, the FAA proposed toremove the stalling speed requirementsfrom paragraphs (c)(2) and (c)(3) and toplace them in paragraph (a)(1). The FAAalso proposed to remove paragraph(c)(4) on cooling climb speed data sincemost airplanes cool at scheduledspeeds.

The FAA proposes to revise paragraph(c)(1) to pertain to the takeoff distancedetermined under § 23.53 and to thetype of surface. Proposed paragraphs(c)(2) and (c)(3) pertain to the effect ontakeoff distance of the runway surface,slope, and headwind and tailwindcomponent.

The FAA proposed to reviseparagraph (c)(4) to add a newrequirement pertaining to the one-engine inoperative takeoff climb/descent performance for WAT-limitedairplanes. This pertains only toreciprocating engine-powered airplanes.It provides the pilot with theinformation determined under final§ 23.66.

The FAA proposed a new paragraph(c)(5), which pertains to enroute rateand gradient and climb/descentdetermined under § 23.69(b), formultiengine airplanes.

The FAA proposed to revised§ 23.1587(d) to incorporate intocommuter category airplanes the presentdata and accelerate-stop data,overweight landing performance, andthe effect of operation on other thansmooth hard surfaces. In addition, inorder to consolidate all of therequirements for what must appear inthe AFM in subpart G, the FAA

proposed that § 23.1587(d)(10) containthe requirement, found in former§ 23.1323(d), to show the relationshipbetween IAS and CAS in the AFM.


Section 23.1589 Loading Information

The FAA proposed to make editorialchanges in § 23.1589(b) to simplify thetext, with no change in requirements.


Appendix E

The FAA proposed to removeAppendix E and to reserve it for thereasons given in the change to § 23.25.

No comments were received on theproposal, and Appendix E is removedand reserved as proposed.

Regulatory Evaluation, RegulatoryFlexibility Determination, and TradeImpact Assessment

Changes to Federal regulations mustundergo several economic analyses.First, Executive Order 12866 directsFederal agencies to promulgate newregulations only if the potential benefitsto society justify its costs. Second, theRegulatory Flexibility Act of 1980requires agencies to analyze theeconomic impact of regulatory changeson small entities. Finally, the Office ofManagement and Budget directsagencies to assess the effects ofregulatory changes on internationaltrade. In conducting these assessments,the FAA has determined that this rule:(1) Will generate benefits exceeding itscosts and is ‘‘significant’’ as defined inthe Executive Order; (2) is ‘‘significant’’as defined in DOT’s Policies andProcedures; (3) will not have asignificant impact on a substantialnumber of small entities; and (4) willnot constitute a barrier to internationaltrade. These analyses, available in thedocket, are summarized below.

Comments Related to the Economics ofthe Proposed Rule

One comment was received regardingthe economics, § 23.143 Controllabilityand Maneuverability. This comment, aswell as the FAA’s response, areincluded in the section ‘‘Discussion ofAmendments.’’

Regulatory Evaluation Summary

The FAA has identified 15 sectionsthat will result in additional compliancecosts to one or more airplane categories.Amendments to five sections will resultin cost savings. The greatest costs willbe incurred by manufacturers of WAT


limited airplanes (e.g., multiengineairplanes with maximum weights ofmore than 6,000 pounds). Whenamortized over a production run, theincremental costs will have a negligibleimpact on airplane prices, less than$100 per airplane.

The primary benefit of the rule will bethe cost efficiencies of harmonizationwith the JAR for those manufacturersthat choose to market airplanes in JAAcountries as well as to manufacturers inJAA countries that market airplanes inthe United States. Other benefits of therule will be decreased reliance onspecial conditions, simplification of thecertification process throughclarification of existing requirements,and increased flexibility throughoptional designs.

Regulatory Flexibility DeterminationThe Regulatory Flexibility Act of 1980

(RFA) was enacted by Congress toensure that small entities are notunnecessarily and disproportionatelyburdened by Federal regulations. TheRFA requires a Regulatory FlexibilityAnalysis if a rule will have a significanteconomic impact, either detrimental orbeneficial, on a substantial number ofsmall entities. Based on FAA Order2100.14A, Regulatory Flexibility Criteriaand Guidance, the FAA has determinedthat the rule will not have a significanteconomic impact on a substantialnumber of small entities.

International Trade Impact AssessmentThe rule will not constitute a barrier

to international trade, including theexport of American airplanes to foreigncountries and the impact of foreignairplanes into the United States. Instead,the flight certification procedures havebeen harmonized with those of the JAAand will lessen restraints on trade.

Federalism ImplicationsThe regulations herein will not have

substantial direct effects on the States,on the relationship between the nationalgovernment and the States, or on thedistribution of power andresponsibilities among the variouslevels of government. Therefore, inaccordance with Executive Order 12612,it is determined that this rule does nothave sufficient federalism implicationsto warrant the preparation of aFederalism Assessment.

ConclusionThe FAA is revising the flight

airworthiness standards for normal,utility, acrobatic, and commutercategory airplanes to harmonize themwith the standards of the Joint AviationAuthorities in Europe for the same

category airplanes. The revisions willreduce the regulatory burden on theUnited States and European airplanemanufacturers by relieving them of theneed to show compliance with differentstandards each time they seekcertification approval of an airplane inthe United States or in a country that isa member of the JAA.

For the reasons discussed in thepreamble, and based on the findings inthe Regulatory Evaluation, the FAA hasdetermined that this rule is significantunder Executive Order 12866. Inaddition, the FAA certifies that this rulewill not have a significant economicimpact, positive or negative, on asubstantial number of small entitiesunder the criteria of the RegulatoryFlexibility Act. This rule is consideredsignificant under DOT RegulatoryPolicies and Procedures (44 FR 11034,February 26, 1979). A regulatoryevaluation of the rule has been placedin the docket. A copy may be obtainedby contracting the person identifiedunder FOR FURTHER INFORMATIONCONTACT.

List of Subjects

14 CFR Part 1

Air transportation.

14 CFR Part 23

Aircraft, Aviation safety, Signs andsymbols.

The Amendments

In consideration of the foregoing, theFederal Aviation Administrationamends 14 CFR parts 1 and 23 to readas follows:

PART 1—DEFINITIONS ANDABBREVIATIONS


Authority: 49 U.S.C. 106(g), 40113, 44701,44702, 44704.

2. A new definition is added inalphabetical order to § 1.1 to read asfollows:

§ 1.1 General definitions.

* * * * * * *Maximum speed for stability

characteristics, VFC/MFC means a speedthat may not be less than a speedmidway between maximum operatinglimit speed (VMO/MMO) anddemonstrated flight diving speed (VDF/MDF), except that, for altitudes wherethe Mach number is the limiting factor,MFC need not exceed the Mach numberat which effective speed warningoccurs.* * * * *

PART 23—AIRWORTHINESSSTANDARDS: NORMAL, UTILITY,ACROBATIC, AND COMMUTERCATEGORY AIRPLANES


Authority: 49 U.S.C. 106(g), 40113, 44701,44702, 44704.

4. Section 23.3 is amended by revisingparagraphs (b)(2), (d), and (e) to read asfollows:

§ 23.3 Airplane categories.

* * * * *(b) * * *(2) Lazy eights, chandelles, and steep

turns, or similar maneuvers, in whichthe angle of bank is more than 60degrees but not more than 90 degrees.* * * * *

(d) The commuter category is limitedto propeller-driven, multiengineairplanes that have a seatingconfiguration, excluding pilot seats, of19 or less, and a maximum certificatedtakeoff weight of 19,000 pounds or less.The commuter category operation islimited to any maneuver incident tonormal flying, stalls (except whipstalls), and steep turns, in which theangle of bank is not more than 60degrees.

(e) Except for commuter category,airplanes may be type certificated inmore than one category if therequirements of each requested categoryare met.

5. Section 23.25 is amended byrevising paragraphs (a) introductory textand (a)(1) introductory text, andparagraphs (a)(1)(i) and (a)(1)(iii) to readas follows:

§ 23.25 Weight limits.(a) Maximum weight. The maximum

weight is the highest weight at whichcompliance with each applicablerequirement of this part (other thanthose complied with at the designlanding weight) is shown. Themaximum weight must be established sothat it is—

(1) Not more than the least of—(i) The highest weight selected by the

applicant; or* * * * *

(iii) The highest weight at whichcompliance with each applicable flightrequirement is shown, and* * * * *

6. Section 23.33 is amended byrevising paragraphs (b) (1) and (2) toread as follows:

§ 23.33 Propeller speed and pitch limits.(b) * * *(1) During takeoff and initial climb at

the all engine(s) operating climb speed


specified in § 23.65, the propeller mustlimit the engine r.p.m., at full throttle orat maximum allowable takeoff manifoldpressure, to a speed not greater than themaximum allowable takeoff r.p.m.; and

(2) During a closed throttle glide, atVNE, the propeller may not cause anengine speed above 110 percent ofmaximum continuous speed.* * * * *

7. Section 23.45 is revised to read asfollows:

§ 23.45 General.(a) Unless otherwise prescribed, the

performance requirements of this partmust be met for—

(1) Still air and standard atmosphere;and

(2) Ambient atmospheric conditions,for commuter category airplanes, forreciprocating engine-powered airplanesof more than 6,000 pounds maximumweight, and for turbine engine-poweredairplanes.

(b) Performance data must bedetermined over not less than thefollowing ranges of conditions—

(1) Airport altitudes from sea level to10,000 feet; and

(2) For reciprocating engine-poweredairplanes of 6,000 pounds, or less,maximum weight, temperature fromstandard to 30 °C above standard; or

(3) For reciprocating engine-poweredairplanes of more than 6,000 poundsmaximum weight and turbine engine-powered airplanes, temperature fromstandard to 30 °C above standard, or themaximum ambient atmospherictemperature at which compliance withthe cooling provisions of § 23.1041 to§ 23.1047 is shown, if lower.

(c) Performance data must bedetermined with the cowl flaps or othermeans for controlling the engine coolingair supply in the position used in thecooling tests required by § 23.1041 to§ 23.1047.

(d) The available propulsive thrustmust correspond to engine power, notexceeding the approved power, less—

(1) Installation losses; and(2) The power absorbed by the

accessories and services appropriate tothe particular ambient atmosphericconditions and the particular flightcondition.

(e) The performance, as affected byengine power or thrust, must be basedon a relative humidity:

(1) Of 80 percent at and belowstandard temperature; and

(2) From 80 percent, at the standardtemperature, varying linearly down to34 percent at the standard temperatureplus 50 °F.

(f) Unless otherwise prescribed, indetermining the takeoff and landing

distances, changes in the airplane’sconfiguration, speed, and power mustbe made in accordance with proceduresestablished by the applicant foroperation in service. These proceduresmust be able to be executed consistentlyby pilots of average skill in atmosphericconditions reasonably expected to beencountered in service.

(g) The following, as applicable, mustbe determined on a smooth, dry, hard-surfaced runway—

(1) Takeoff distance of § 23.53(b);(2) Accelerate-stop distance of § 23.55;(3) Takeoff distance and takeoff run of

§ 23.59; and(4) Landing distance of § 23.75.Note: The effect on these distances of

operation on other types of surfaces (forexample, grass, gravel) when dry, may bedetermined or derived and these surfaceslisted in the Airplane Flight Manual inaccordance with § 23.1583(p).

(h) For commuter category airplanes,the following also apply:

(1) Unless otherwise prescribed, theapplicant must select the takeoff,enroute, approach, and landingconfigurations for the airplane.

(2) The airplane configuration mayvary with weight, altitude, andtemperature, to the extent that they arecompatible with the operatingprocedures required by paragraph (h)(3)of this section.

(3) Unless otherwise prescribed, indetermining the critical-engine-inoperative takeoff performance, takeoffflight path, and accelerate-stop distance,changes in the airplane’s configuration,speed, and power must be made inaccordance with procedures establishedby the applicant for operation in service.

(4) Procedures for the execution ofdiscontinued approaches and balkedlandings associated with the conditionsprescribed in § 23.67(c)(4) and § 23.77(c)must be established.

(5) The procedures established underparagraphs (h)(3) and (h)(4) of thissection must—

(i) Be able to be consistently executedby a crew of average skill inatmospheric conditions reasonablyexpected to be encountered in service;

(ii) Use methods or devices that aresafe and reliable; and

(iii) Include allowance for anyreasonably expected time delays in theexecution of the procedures.


§ 23.49 Stalling period.(a) VSO and VS1 are the stalling speeds

or the minimum steady flight speeds, inknots (CAS), at which the airplane iscontrollable with—

(1) For reciprocating engine-poweredairplanes, the engine(s) idling, the

throttle(s) closed or at not more than thepower necessary for zero thrust at aspeed not more than 110 percent of thestalling speed;

(2) For turbine engine-poweredairplanes, the propulsive thrust notgreater than zero at the stalling speed,or, if the resultant thrust has noappreciable effect on the stalling speed,with engine(s) idling and throttle(s)closed;

(3) The propeller(s) in the takeoffposition;

(4) The airplane in the conditionexisting in the test, in which VSO andVS1 are being used;

(5) The center of gravity in theposition that results in the highest valueof VSO and VS1; and

(6) The weight used when VSO andVS1 are being used as a factor todetermine compliance with a requiredperformance standard.

(b) VSO and VS1 must be determinedby flight tests, using the procedure andmeeting the flight characteristicsspecified in § 23.201.

(c) Except as provided in paragraph(d) of this section, VSO and VS1 atmaximum weight must not exceed 61knots for—

(1) Single-engine airplanes; and(2) Multiengine airplanes of 6,000

pounds or less maximum weight thatcannot meet the minimum rate of climbspecified in § 23.67(a) (1) with thecritical engine inoperative.

(d) All single-engine airplanes, andthose multiengine airplanes of 6,000pounds or less maximum weight with aVSO of more than 61 knots that do notmeet the requirements of § 23.67(a)(1),must comply with § 23.562(d).


§ 23.51 Takeoff speeds.(a) For normal, utility, and acrobatic

category airplanes, rotation speed, VR, isthe speed at which the pilot makes acontrol input, with the intention oflifting the airplane out of contact withthe runway or water surface.

(1) For multiengine landplanes, VR,must not be less than the greater of 1.05VMC; or 1.10 VS1;

(2) For single-engine landplanes, VR,must not be less than VS1; and

(3) For seaplanes and amphibianstaking off from water, VR, may be anyspeed that is shown to be safe under allreasonably expected conditions,including turbulence and completefailure of the critical engine.

(b) For normal, utility, and acrobaticcategory airplanes, the speed at 50 feetabove the takeoff surface level must notbe less than:

(1) or multiengine airplanes, thehighest of—


(i) A speed that is shown to be safefor continued flight (or emergencylanding, if applicable) under allreasonably expected conditions,including turbulence and completefailure of the critical engine;

(ii) 1.10 VMC; or(iii) 1.20 VS1.(2) For single-engine airplanes, the

higher of—(i) A speed that is shown to be safe

under all reasonably expectedconditions, including turbulence andcomplete engine failure; or

(ii) 1.20 VS1.(c) For commuter category airplanes,

the following apply:(l) V1 must be established in relation

to VEF as follows:(i) VEF is the calibrated airspeed at

which the critical engine is assumed tofail. VEF must be selected by theapplicant but must not be less than 1.05VMC determined under § 23.149(b) or, atthe option of the applicant, not less thanVMCG determined under § 23.149(f).

(ii) The takeoff decision speed, V1, isthe calibrated airspeed on the ground atwhich, as a result of engine failure orother reasons, the pilot is assumed tohave made a decision to continue ordiscontinue the takeoff. The takeoffdecision speed, V1, must be selected bythe applicant but must not be less thanVEF plus the speed gained with thecritical engine inoperative during thetime interval between the instant atwhich the critical engine is failed andthe instant at which the pilot recognizesand reacts to the engine failure, asindicated by the pilot’s application ofthe first retarding means during theaccelerate-stop determination of § 23.55.

(2) The rotation speed, VR, in terms ofcalibrated airspeed, must be selected bythe applicant and must not be less thanthe greatest of the following:

(i) V1;(ii) 1.05 VMC determined under

§ 23.149(b);(iii) 1.10 VS1; or(iv) The speed that allows attaining

the initial climb-out speed, V2, beforereaching a height of 35 feet above thetakeoff surface in accordance with§ 23.57(c)(2).

(3) For any given set of conditions,such as weight, altitude, temperature,and configuration, a single value of VR

must be used to show compliance withboth the one-engine-inoperative takeoffand all-engines-operating takeoffrequirements.

(4) The takeoff safety speed, V2, interms of calibrated airspeed, must beselected by the applicant so as to allowthe gradient of climb required in § 23.67(c)(1) and (c)(2) but mut not be less than1.10 VMC or less than 1.20 VS1.

(5) The one-engine-inoperative takeoffdistance, using a normal rotation rate ata speed 5 knots less than VR, establishedin accordance with paragraph (c)(2) ofthis section, must be shown not toexceed the corresponding one-engine-inoperative takeoff distance, determinedin accordance with § 23.57 and§ 23.59(a)(1), using the established VR.The takeoff, otherwise performed inaccordance with § 23.57, must becontinued safely from the point atwhich the airplane is 35 feet above thetakeoff surface and at a speed not lessthan the established V2 minus 5 knots.

(6) The applicant must show, with allengines operating, that marked increasesin the scheduled takeoff distances,determined in accordance with§ 23.59(a)(2), do not result from over-rotation of the airplane or out-of-trimconditions.


§ 23.53 Takeoff performance.(a) For normal, utility, and acrobatic

category airplanes, the takeoff distancemust be determined in accordance withparagraph (b) of this section, usingspeeds determined in accordance with§ 23.51 (a) and (b).

(b) For normal, utility, and acrobaticcategory airplanes, the distance requiredto takeoff and climb to a height of 50feet above the takeoff surface must bedetermined for each weight, altitude,and temperature within the operationallimits established for takeoff with—

(1) Takeoff power on each engine;(2) Wing flaps in the takeoff

position(s); and(3) Landing gear extended.(c) For commuter category airplanes,

takeoff performance, as required by§§ 23.55 through 23.59, must bedetermined with the operating engine(s)within approved operating limitations.

11. Section 23.55 is amended byrevising paragraph (a) and theintroductory text of paragraph (b) toread as follows:

§ 23.55 Accelerate-stop distance.

* * * * *(a) The accelerate-stop distance is the

sum of the distances necessary to—(1) Accelerate the airplane from a

standing start to VEF with all enginesoperating;

(2) Accelerate the airplane from VEF toV1, assuming the critical engine fails atVEF; and

(3) Come to a full stop from the pointat which V1 is reached.

(b) Means other than wheel brakesmay be used to determine theaccelerate-stop distances if that means—* * * * *

12. Section 23.57 is amended byrevising paragraphs (a) introductorytext, (b), (c)(1), (c)(3) introductory text,(c)(4), and (d); and by adding a newparagraph (e) to read as follows:

§ 23.57 Takeoff path.

* * * * *(a) The takeoff path extends from a

standing start to a point in the takeoffat which the airplane is 1500 feet abovethe takeoff surface at or below whichheight the transition from the takeoff tothe enroute configuration must becompleted; and* * * * *

(b) During the acceleration to speedV2, the nose gear may be raised off theground at a speed not less than VR.However, landing gear retraction mustnot be initiated until the airplane isairborne.

(c) * * *(1) The slope of the airborne part of

the takeoff path must not be negative atany point;* * * * *

(3) At each point along the takeoffpath, starting at the point at which theairplane reaches 400 feet above thetakeoff surface, the available gradient ofclimb must not be less than—* * * * *

(4) Except for gear retraction andautomatic propeller feathering, theairplane configuration must not bechanged, and no change in power thatrequires action by the pilot may bemade, until the airplane is 400 feetabove the takeoff surface.

(d) The takeoff path to 35 feet abovethe takeoff surface must be determinedby a continuous demonstrated takeoff.

(e) The takeoff path to 35 feet abovethe takeoff surface must be determinedby synthesis from segments; and

(1) The segments must be clearlydefined and must be related to distinctchanges in configuration, power, andspeed;

(2) The weight of the airplane, theconfiguration, and the power must beassumed constant throughout eachsegment and must correspond to themost critical condition prevailing in thesegment; and

(3) The takeoff flight path must bebased on the airplane’s performancewithout utilizing ground effect.

13. Section 23.59 is amended byrevising the introductory text, paragraph(a)(2), and paragraph (b) to read asfollows:

§ 23.59 Takeoff distance and takeoff run.For each commuter category airplane,

the takeoff distance and, at the option ofthe applicant, the takeoff run, must bedetermined.


(a) * * *(2) With all engines operating, 115

percent of the horizontal distance fromthe start of the takeoff to the point atwhich the airplane is 35 feet above thetakeoff surface, determined by aprocedure consistent with § 23.57.

(b) If the takeoff distance includes aclearway, the takeoff run is the greaterof—

(1) The horizontal distance along thetakeoff path from the start of the takeoffto a point equidistant between the liftoffpoint and the point at which theairplane is 35 feet above the takeoffsurface as determined under § 23.57; or

(2) With all engines operating, 115percent of the horizontal distance fromthe start of the takeoff to a pointequidistant between the liftoff point andthe point at which the airplane is 35 feetabove the takeoff surface, determined bya procedure consistent with § 23.57.

14. A new § 23.63 is added to read asfollows:

§ 23.63 Climb: general.(a) Compliance with the requirements

of §§ 23.65, 23.66, 23.67, 23.69, and23.77 must be shown—

(1) Out of ground effect; and(2) At speeds that are not less than

those at which compliance with thepowerplant cooling requirements of§§ 23.1041 to 23.1047 has beendemonstrated; and

(3) Unless otherwise specified, withone engine inoperative, at a bank anglenot exceeding 5 degrees.

(b) For normal, utility, and acrobaticcategory reciprocating engine-poweredairplanes of 6,000 pounds or lessmaximum weight, compliance must beshown with § 23.65(a), § 23.67(a), whereappropriate, and § 23.77(a) at maximumtakeoff or landing weight, asappropriate, in a standard atmosphere.

(c) For normal, utility, and acrobaticcategory reciprocating engine-poweredairplanes of more than 6,000 poundsmaximum weight, and turbine engine-powered airplanes in the normal, utility,and acrobatic category, compliancemust be shown at weights as a functionof airport altitude and ambienttemperature, within the operationallimits established for takeoff andlanding, respectively, with—

(1) Sections 23.65(b) and 23.67(b) (1)and (2), where appropriate, for takeoff,and

(2) Section 23.67(b)(2), whereappropriate, and § 23.77(b), for landing.

(d) For commuter category airplanes,compliance must be shown at weightsas a function of airport altitude andambient temperature within theoperational limits established for takeoffand landing, respectively, with—

(1) Sections 23.67(c)(1), 23.67(c)(2),and 23.67(c)(3) for takeoff; and

(2) Sections 23.67(c)(3), 23.67(c)(4),and 23.77(c) for landing.


§ 23.65 Climb: all engines operating.(a) Each normal, utility, and acrobatic

category reciprocating engine-poweredairplane of 6,000 pounds or lessmaximum weight must have a steadyclimb gradient at sea level of at least 8.3percent for landplanes or 6.7 percet forseaplanes and amphibians with—

(1) Not more than maximumcontinuous power on each engine;

(2) The landing gear retracted;(3) The wing flaps in the takeoff

position(s); and(4) A climb speed not less than the

greater of 1.1 VMC and 1.2 VS1 formultiengine airplanes and not less than1.2 VS1 for single—engine airplanes.

(b) Each normal, utility, and acrobaticcategory reciprocating engine-poweredairplane of more than 6,000 poundsmaximum weight and turbine engine-powered airplanes in the normal, utility,and acrobatic category must have asteady gradient of climb after takeoff ofat least 4 percent with

(1) Take off power on each engine;(2) The landing gear extended, except

that if the landing gear can be retractedin not more than sven seconds, the testmay be conducted with the gearretracted;

(3) The wing flaps in the takeoffposition(s); and

(4) A climb speed as specified in§ 23.65(a)(4).


§ 23.66 Takeoff climb: One-engineinoperative.

For normal, utility, and acrobaticcategory reciprocating engine-poweredairplanes of more than 6,000 poundsmaximum weight, and turbine engine-powered airplanes in the normal, utility,and acrobatic category, the steadygradient of climb or descent must bedetermined at each weight, altitude, andambient temperature within theoperational limits established by theapplicant with—

(a) The critical engine inoperative andits propeller in the position it rapidlyand automatically assumes;

(b) The remaining engine(s) at takeoffpower;

(c) The landing gear extended, exceptthat if the landing gear can be retractedin not more than seven seconds, the testmay be conducted with the gearretracted;

(d) The wing flaps in the takeoffposition(s):

(e) The wings level; and(f) A climb speed equal to that

achieved at 50 feet in the demonstrationof § 23.53.


§ 23.67 Climb: One engine inoperative.(a) For normal, utility, and acrobatic

category reciprocating engine-poweredairplanes of 6,000 pounds or lessmaximum weight, the following apply:

(1) Except for those airplanes thatmeet the requirements prescribed in§ 23.562(d), each airplane with a VSO ofmore than 61 knots must be able tomaintain a steady climb gradient of atleast 1.5 percent at a pressure altitudeof 5,000 feet with the—

(i) Critical engine inoperative and itspropeller in the minimum drag position;

(ii) Remaining engine(s) at not morethan maximum continuous power;

(iii) Landing gear retracted;(iv) Wing flaps retracted; and(v) Climb speed not less than 1.2 VS1.(2) For each airplane that meets the

requirements prescribed in § 23.562(d),or that has a VSO of 61 knots or less, thesteady gradient of climb or descent at apressure altitude of 5,000 feet must bedetermined with the—



(iii) Landing gear retracted;(iv) Wing flaps retracted; and(v) Climb speed not less than 1.2VS1.(b) For normal, utility, and acrobatic

category reciprocating engine-poweredairplanes of more than 6,000 poundsmaximum weight, and turbine engine-powered airplanes in the normal, utility,and acrobatic category—

(1) The steady gradient of climb at analtitude of 400 feet above the takeoffmust be measurably positive with the—


(ii) Remaining engine(s) at takeoffpower;

(iii) Landing gear retracted;(iv) Wing flaps in the takeoff

position(s); and(v) Climb speed equal to that achieved

at 50 feet in the demonstration of§ 23.53.

(2) The steady gradient of climb mustnot be less than 0.75 percent at analtitude of 1,500 feet above the takeoffsurface, or landing surface, asappropriate, with the—



(iii) Landing gear retracted;(iv) Wing flaps retracted; and


(v) Climb speed not less than 1.2 VS1.(c) For commuter category airplanes,

the following apply:(1) Takeoff; landing gear extended.

The steady gradient of climb at thealtitude of the takeoff surface must bemeasurably positive for two-engineairplanes, not less than 0.3 percent forthree-engine airplanes, or 0.5 percent forfour-engine airplanes with—

(i) The critical engine inoperative andits propeller in the position it rapidlyand automatically assumes;

(ii) The remaining engine(s) at takeoffpower;

(iii) The landing gear extended, andall landing gear doors open;

(iv) The wing flaps in the takeoffposition(s);

(v) The wings level; and(vi) A climb speed equal to V2.(2) Takeoff; landing gear retracted.

The steady gradient of climb at analtitude of 400 feet above the takeoffsurface must be not less than 2.0 percentof two-engine airplanes, 2.3 percent forthree-engine airplanes, and 2.6 percentfor four-engine airplanes with—

(i) The critical engine inoperative andits propeller in the position it rapidlyand automatically assumes;


(iii) The landing gear retracted;(iv) The wing flaps in the takeoff

position(s);(v) A climb speed equal to V2.(3) Enroute. The steady gradient of

climb at an altitude of 1,500 feet abovethe takeoff or landing surface, asappropriate, must be not less than 1.2percent for two-engine airplanes, 1.5percent for three-engine airplanes, and1.7 percent for four-engine airplaneswith—

(i) The critical engine inoperative andits propeller in the minimum dragposition;

(ii) The remaining engine(s) at notmore than maximum continuous power;

(iii) The landing gear retracted;(iv) The wing flaps retracted; and(v) A climb speed not less than 1.2

VS1.(4) Discontinued approach. The

steady gradient of climb at an altitudeof 400 feet above the landing surfacemust be not less than 2.1 percent fortwo-engine airplanes, 2.4 percent forthree-engine airplanes, and 2.7 percentfor four-engine airplanes, with—

(i) The critical engine inoperative andits propeller in the minimum dragposition;


(iii) Landing gear retracted;(iv) Wing flaps in the approach

position(s) in which VS1 for these

position(s) does not exceed 110 percentof the VS1 for the related all-engines-operated landing position(s); and

(v) A climb speed established inconnection with normal landingprocedures but not exceeding 1.5 VS1.


§ 23.69 Enroute climb/descent.(a) All engines operating. The steady

gradient and rate of climb must bedetermined at each weight, altitude, andambient temperature within theoperational limits established by theapplicant with—

(1) Not more than maximumcontinuous power on each engine;

(2) The landing gear retracted;(3) The wing flaps retracted; and(4) A climb speed not less than 1.3

VS1.(b) One engine inoperative. The

steady gradient and rate of climb/descent must be determined at eachweight, altitude, and ambienttemperature within the operationallimits established by the applicantwith—

(1) The critical engine inoperative andits propeller in the minimum dragposition;

(2) The remaining engine(s) at notmore than maximum continuous power;

(3) The landing gear retracted;(4) The wing flaps retracted; and(5) A climb speed not less than 1.2

VS1.19. A new § 23.71 is added to read as

follows:

§ 23.71 Glide: Single-engine airplanes.The maximum horizontal distance

traveled in still air, in nautical miles,per 1,000 feet of altitude lost in a glide,and the speed necessary to achieve thismust be determined with the engineinoperative, its propeller in theminimum drag position, and landinggear and wing flaps in the mostfavorable available position.


§ 23.73 Reference landing approachspeed.

(a) For normal, utility, and acrobaticcategory reciprocating engine-poweredairplanes of 6,000 pounds or lessmaximum weight, the reference landingapproach speed, VREF, must not be lessthan the greater of VMC, determined in§ 23.149(b) with the wing flaps in themost extended takeoff position, and 1.3VSO.

(b) For normal, utility, and acrobaticcategory reciprocating engine-poweredairplanes of more than 6,000 poundsmaximum weight, and turbine engine-powered airplanes in the normal, utility,

and acrobatic category, the referencelanding approach speed, VREF, must notbe less than the greater of VMC,determined in § 23.149(c), and 1.3 VSO.

(c) For commuter category airplanes,the reference landing approach speed,VREF, must not be less than the greaterof 1.05 VMC, determined in § 23.149(c),and 1.3 VSO.

21. Section 23.75 is amended byrevising the section heading,introductory text, the introductory textof paragraph (a), and paragraphs (b), (d),(e), and (f); and by removing paragraph(h), to read as follows:

§ 23.75 Landing distance.The horizontal distance necessary to

land and come to a complete stop froma point 50 feet above the landing surfacemust be determined, for standardtemperatures at each weight andaltitude within the operational limitsestablished for landing, as follows:

(a) A steady approach at not less thanVREF, determined in accordance with§ 23.73 (a), (b), or (c), as appropriate,must be maintained down to the 50 footheight and—* * * * *

(b) A constant configuration must bemaintained throughout the maneuver.* * * * *

(d) It must be shown that a safetransition to the balked landingconditions of § 23.77 can be made fromthe conditions that exist at the 50 footheight, at maximum landing weight, orat the maximum landing weight foraltitude and temperature of § 23.63(c)(2) or (d)(2), as appropriate.

(e) The brakes must be used so as tonot cause excessive wear of brakes ortires.

(f) Retardation means other thanwheel brakes may be used if thatmeans—

(1) Is safe and reliable; and(2) Is used so that consistent results

can be expected in service.* * * * *


§ 23.77 Balked landing.(a) Each normal, utility, and acrobatic

category reciprocating engine-poweredairplane at 6,000 pounds or lessmaximum weight must be able tomaintain a steady gradient of climb atsea level of at least 3.3 percent with—

(1) Takeoff power on each engine;(2) The landing gear extended;(3) The wing flaps in the landing

position, except that if the flaps maysafely be retracted in two seconds orless without loss of altitude and withoutsudden changes of angle of attack, theymay be retracted; and


(4) A climb speed equal to VREF, asdefined in § 23.73(a).

(b) Each normal, utility, and acrobaticcategory reciprocating engine-poweredairplane of more than 6,000 poundsmaximum weight and each normal,utility, and acrobatic category turbineengine-powered airplane must be able tomaintain a steady gradient of climb ofat least 2.5 percent with—

(1) Not more than the power that isavailable on each engine eight secondsafter initiation of movement of thepower controls from minimum flight-idle position;

(2) The landing gear extended;(3) The wing flaps in the landing

position; and(4) A climb speed equal to VREF, as

defined in § 23.73(b).(c) Each commuter category airplane

must be able to maintain a steadygradient of climb of at least 3.2 percentwith—

(1) Not more than the power that isavailable on each engine eight secondsafter initiation of movement of thepower controls from the minimum flightidle position;

(2) Landing gear extended;(3) Wing flaps in the landing position;

and(4) A climb speed equal to VREF, as

defined in § 23.73(c).23. Section 23.143 is amended by

revising paragraphs (a) and (c) to read asfollows:

§ 23.143 General.

(a) The airplane must be safelycontrollable and maneuverable duringall flight phases including—

(1) Takeoff;(2) Climb;(3) Level flight;(4) Descent;(5) Go-around; and(6) Landing (power on and power off)

with the wing flaps extended andretracted.* * * * *

(c) If marginal conditions exist withregard to required pilot strength, thecontrol forces necessary must bedetermined by quantitative tests. In nocase may the control forces under theconditions specified in paragraphs (a)and (b) of this section exceed thoseprescribed in the following table:

Values inpounds force ap-plied to the rel-evant control

Pitch Roll Yaw

(a) For tem-porary applica-tion:Stick ............... 60 30 ............

Values inpounds force ap-plied to the rel-evant control

Pitch Roll Yaw

Wheel (Twohands onrim) ............. 75 50 ............

Wheel (Onehand onrim) ............. 50 25 ............

Rudder Pedal ............ ............ 150(b) For pro-

longed appli-cation ............. 10 5 20

24. Section 23.145 is amended byrevising paragraph (b) introductory text,paragraphs (b)(2) through (b)(5); addinga new paragraph (b)(6); and revisingparagraphs (c) and (d) to read as follows:

§ 23.145 Longitudinal control.

* * * * *(b) Unless otherwise required, it must

be possible to carry out the followingmaneuvers without requiring theapplication of single-handed controlforces exceeding those specified in§ 23.143(c). The trimming controls mustnot be adjusted during the maneuvers:* * * * *

(2) With landing gear and flapsextended, power off, and the airplane asnearly as possible in trim at 1.3 VSO,quickly apply takeoff power and retractthe flaps as rapidly as possible to therecommended go around setting andallow the airspeed to transition from 1.3VSO to 1.3 VS1. Retract the gear when apositive rate of climb is established.

(3) With landing gear and flapsextended, in level flight, powernecessary to attain level flight at 1.1VSO, and the airplane as nearly aspossible in trim, it must be possible tomaintain approximately level flightwhile retracting the flaps as rapidly aspossible with simultaneous applicationof not more than maximum continuouspower. If gated flat positions areprovided, the flap retraction may bedemonstrated in stages with power andtrim reset for level flight at 1.1 VS1, inthe initial configuration for each stage—

(i) From the fully extended position tothe most extended gated position;

(ii) Between intermediate gatedpositions, if applicable; and

(iii) From the least extended gatedposition to the fully retracted position.

(4) With power off, flaps and landinggear retracted and the airplane as nearlyas possible in trim at 1.4 VS1, applytakeoff power rapidly while maintainingthe same airspeed.

(5) With power off, landing gear andflaps extended, and the airplane asnearly as possible in trim at VREF, obtainand maintain airspeeds between 1.1

VSO, and either 1.7 VSO or VFE,whichever is lower without requiringthe application of two-handed controlforces exceeding those specified in§ 23.143(c).

(6) With maximum takeoff power,landing gear retracted, flaps in thetakeoff position, and the airplane asnearly as possible in trim at VFE

appropriate to the takeoff flap position,retract the flaps as rapidly as possiblewhile maintaining constant speed.

(c) At speeds above VMO/MMO, and upto the maximum speed shown under§ 23.251, a maneuvering capability of1.5 g must be demonstrated to providea margin to recover from upset orinadvertent speed increase.

(d) It must be possible, with a pilotcontrol force of not more than 10pounds, to maintain a speed of not morethan VREF during a power-off glide withlanding gear and wing flaps extended,for any weight of the airplane, up to andincluding the maximum weight.* * * * *


§ 23.147 Directional and lateral control.

(a) For each multiengine airplane, itmust be possible, while holding thewings level within five degrees, to makesudden changes in heading safely inboth directions. This ability must beshown at 1.4 VS1 with heading changesup to 15 degrees, except that theheading change at which the rudderforce corresponds to the limits specifiedin § 23.143 need not be exceeded, withthe—

(1) Critical engine inoperative and itspropeller in the minimum drag position;

(2) Remaining engines at maximumcontinuous power;

(3) Landing gear—(i) Retracted; and(ii) Extended; and(4) Flaps retracted.(b) For each multiengine airplane, it

must be possible to regain full controlof the airplane without exceeding abank angle of 45 degrees, reaching adangerous attitude or encounteringdangerous characteristics, in the eventof a sudden and complete failure of thecritical engine, making allowance for adelay of two seconds in the initiation ofrecovery action appropriate to thesituation, with the airplane initially intrim, in the following condition:

(1) Maximum continuous power oneach engine;

(2) The wing flaps retracted;(3) The landing gear retracted;(4) A speed equal to that at which

compliance with § 23.69(a) has beenshown; and


(5) All propeller controls in theposition at which compliance with§ 23.69(a) has been shown.

(c) For all airplanes, it must be shownthat the airplane is safely controllablewithout the use of the primary lateralcontrol system in any all-engineconfiguration(s) and at any speed oraltitude within the approved operatingenvelope. It must also be shown that theairplane’s flight characteristics are notimpaired below a level needed to permitcontinued safe flight and the ability tomaintain attitudes suitable for acontrolled landing without exceedingthe operational and structurallimitations of the airplane. If a singlefailure of any one connecting ortransmitting link in the lateral controlsystem would also cause the loss ofadditional control system(s),compliance with the above requirementmust be shown with those additionalsystems also assumed to be inoperative.


§ 23.149 Minimum control speed.

(a) VMC is the calibrated airspeed atwhich, when the critical engine issuddenly made inoperative, it ispossible to maintain control of theairplane with that engine stillinoperative, and thereafter maintainstraight flight at the same speed with anangle of bank of not more than 5degrees. The method used to simulatecritical engine failure must represent themost critical mode of powerplant failureexpected in service with respect tocontrollability.

(b) VMC for takeoff must not exceed1.2 VS1, where VS1 is determined at themaximum takeoff weight. VMC must bedetermined with the most unfavorableweight and center of gravity positionand with the airplane airborne and theground effect negligible, for the takeoffconfiguration(s) with—

(1) Maximum available takeoff powerinitially on each engine;

(2) The airplane trimmed for takeoff;(3) Flaps in the takeoff position(s);(4) Landing gear retracted; and(5) All propeller controls in the

recommended takeoff positionthroughout.

(c) For all airplanes exceptreciprocating engine-powered airplanesof 6,000 pounds or less maximumweight, the conditions of paragraph (a)of this section must also be met for thelanding configuration with—

(1) Maximum available takeoff powerinitially on each engine;

(2) The airplane trimmed for anapproach, with all engines operating, atVREF, at an approach gradient equal to

the steepest used in the landing distancedemonstration of § 23.75;

(3) Flaps in the landing position;(4) Landing gear extended; and(5) All propeller controls in the

position recommended for approachwith all engines operating.

(d) A minimum speed to intentionallyrender the critical engine inoperativemust be established and designated asthe safe, intentional, one-engine-inoperative speed, VSSE.

(e) At VMC, the rudder pedal forcerequired to maintain control must notexceed 150 pounds and it must not benecessary to reduce power of theoperative engine(s). During themaneuver, the airplane must not assumeany dangerous attitude and it must bepossible to prevent a heading change ofmore than 20 degrees.

(f) At the option of the applicant, tocomply with the requirements of§ 23.51(c)(1), VMCG may be determined.VMCG is the minimum control speed onthe ground, and is the calibratedairspeed during the takeoff run atwhich, when the critical engine issuddenly made inoperative, it ispossible to maintain control of theairplane using the rudder control alone(without the use of nosewheel steering),as limited by 150 pounds of force, andusing the lateral control to the extent ofkeeping the wings level to enable thetakeoff to be safely continued. In thedetermination of VMCG, assuming thatthe path of the airplane acceleratingwith all engines operating is along thecenterline of the runway, its path fromthe point at which the critical engine ismade inoperative to the point at whichrecovery to a direction parallel to thecenterline is completed may not deviatemore than 30 feet laterally from thecenterline at any point. VMCG must beestablished with—

(1) The airplane in each takeoffconfiguration or, at the option of theapplicant, in the most critical takeoffconfiguration;

(2) Maximum available takeoff poweron the operating engines;

(3) The most unfavorable center ofgravity;

(4) The airplane trimmed for takeoff;and

(5) The most unfavorable weight inthe range of takeoff weights.


§ 23.153 Control during landings.It must be possible, while in the

landing configuration, to safelycomplete a landing without exceedingthe one-hand control force limitsspecified in § 23.143(c) following anapproach to land—

(a) At a speed of VREF minus 5 knots;(b) With the airplane in trim, or as

nearly as possible in trim and withoutthe trimming control being movedthroughout the maneuver;

(c) At an approach gradient equal tothe steepest used in the landing distancedemonstration of § 23.75; and

(d) With only those power changes, ifany, that would be made when landingnormally from an approach at VREF.

28. Section 23.155 is amended byrevising the introductory text ofparagraph (b) and paragraph (b)(1), andby adding a new paragraph (c) to readas follows:

§ 23.155 Elevator control force inmaneuvers.

* * * * *(b) The requirement of paragraph (a)

of this section must be met at 75 percentof maximum continuous power forreciprocating engines, or the maximumcontinuous power for turbine engines,and with the wing flaps and landinggear retracted—

(1) In a turn, with the trim settingused for wings level flight at VO; and* * * * *

(c) There must be no excessivedecrease in the gradient of the curve ofstick force versus maneuvering loadfactor with increasing load factor.

29. Section 23.157 is amended byrevising paragraph (d) to read asfollows:

§ 23.157 Rate of roll.

* * * * *(d) The requirement of paragraph (c)

of this section must be met when rollingthe airplane in each direction in thefollowing conditions—

(1) Flaps in the landing position(s);(2) Landing gear extended;(3) All engines operating at the power

for a 3 degree approach; and(4) The airplane trimmed at VREF.30. Section 23.161 is amended by

revising paragraphs (a), (b)(1), (b)(2), (c),the introductory text of paragraph (d),and (d)(4), and by adding a newparagraph (e) to read as follows:

§ 23.161 Trim.(a) General. Each airplane must meet

the trim requirements of this sectionafter being trimmed and without furtherpressure upon, or movement of, theprimary controls or their correspondingtrim controls by the pilot or theautomatic pilot. In addition, it must bepossible, in other conditions of loading,configuration, speed and power toensure that the pilot will not be undulyfatigued or distracted by the need toapply residual control forces exceedingthose for prolonged application of


§ 23.143(c). This applies in normaloperation of the airplane and, ifapplicable, to those conditionsassociated with the failure of one enginefor which performance characteristicsare established.

(b) * * *(1) For normal, utility, and acrobatic

category airplanes, at a speed of 0.9 VH,VC, or VMO/MO, whichever is lowest;and

(2) For commuter category airplanes,at all speeds from 1.4 VS1 to the lesserof VH or VMO/MMO.

(c) Longitudinal trim. The airplanemust maintain longitudinal trim undereach of the following conditions:

(1) A climb with—(i) Takeoff power, landing gear

retracted, wing flaps in the takeoffposition(s), at the speeds used indetermining the climb performancerequired by § 23.65; and

(ii) Maximum continuous power atthe speeds and in the configuration usedin determining the climb performancerequired by § 23.69(a).

(2) Level flight at all speeds from thelesser of VH and either VNO or VMO/MMO

(as appropriate), to 1.4 VS1, with thelanding gear and flaps retracted.

(3) A descent at VNO or VMO/MMO,whichever is applicable, with power offand with the landing gear and flapsretracted.

(4) Approach with landing gearextended and with—

(i) A 3 degree angle of descent, withflaps retracted and at a speed of 1.4 VS1;

(ii) A 3 degree angle of descent, flapsin the landing position(s) at VREF; and

(iii) An approach gradient equal to thesteepest used in the landing distancedemonstrations of § 23.75, flaps in thelanding position(s) at VREF.

(d) In addition, each multiple airplanemust maintain longitudinal anddirectional trim, and the lateral controlforce must not exceed 5 pounds at thespeed used in complying with§ 23.67(a), (b)(2), or (c)(3), asappropriate, with—* * * * *

(4) Wing flaps retracted; and* * * * *

(e) In addition, each commutercategory airplane for which, in thedetermination of the takeoff path inaccordance with § 23.57, the climb inthe takeoff configuration at V2 extendsbeyond 400 feet above the takeoffsurface, it must be possible to reducethe longitudinal and lateral controlforces to 10 pounds and 5 pounds,respectively, and the directional controlforce must not exceed 50 pounds at V2

with—

(1) The critical engine inoperative andits propeller in the minimum dragposition;

(2) The remaining engine(s) at takeoffpower;

(3) Landing gear retracted;(4) Wing flaps in the takeoff

position(s); and(5) An angle of bank not exceeding 5

degrees.31. Section 23.175 is revised to read

as follows:

§ 23.175 Demonstration of staticlongitudinal stability.

Static longitudinal stability must beshown as follows:

(a) Climb. The stick force curve musthave a stable slope at speeds between 85and 115 percent of the trim speed,with—

(1) Flaps retracted;(2) Landing gear retracted;(3) Maximum continuous power; and(4) The airplane trimmed at the speed

used in determining the climbperformance required by § 23.69(a).

(b) Cruise. With flaps and landing gearretracted and the airplane in trim withpower for level flight at representativecruising speeds at high and lowaltitudes, including speeds up to VNO orVMO/MMO, as appropriate, except thatthe speed need not exceed VH—

(1) For normal, utility, and acrobaticcategory airplanes, the stick force curvemust have a stable slope at all speedswithin a range that is the greater of 15percent of the trim speed plus theresulting free return speed range, or 40knots plus the resulting free returnspeed range, above and below the trimspeed, except that the slope need not bestable—

(i) At speeds less than 1.3 VS1; or(ii) For airplanes with VNE established

under § 23.1505(a), at speeds greaterthan VNE; or

(iii) For airplanes with VMO/MMO

established under § 23.1505(c), atspeeds greater than VFC/MFC.

(2) For commuter category airplanes,the stick force curve must have a stableslope at all speeds within a range of 50knots plus the resulting free returnspeed range, above and below the trimspeed, except that the slope need not bestable—

(i) At speeds less than 1.4 VS1; or(ii) At speeds greater than VFC/MFC; or(iii) At speeds that require a stick

force greater than 50 pounds.(c) Landing. The stick force curve

must have a stable slope at speedsbetween 1.1 VS1 and 1.8 VS1 with—

(1) Flaps in the landing position;(2) Landing gear extended; and(3) The airplane trimmed at—(i) VREF, or the minimum trim speed

if higher, with power off; and

(ii) VREF with enough power tomaintain a 3 degree angle of descent.


§ 23.177 Static directional and lateralstability.

(a) The static directional stability, asshown by the tendency to recover froma wings level sideslip with the rudderfree, must be positive for any landinggear and flap position appropriate to thetakeoff, climb, cruise, approach, andlanding configurations. This must beshown with symmetrical power up tomaximum continuous power, and atspeeds from 1.2 VS1 up to the maximumallowable speed for the condition beinginvestigated. The angel of sideslip forthese tests must be appropriate to thetype of airplane. At larger angles ofsideslip, up to that at which full rudderis used or a control force limit in§ 23.143 is reached, whichever occursfirst, and at speeds from 1.2 VS1 to VO,the rudder pedal force must not reverse.

(b) The static lateral stability, asshown by the tendency to raise the lowwing in a sideslip, must be positive forall landing gear and flap positions. Thismust be shown with symmetrical powerup to 75 percent of maximumcontinuous power at speeds above 1.2VS1 in the take off configuration(s) andat speeds above 1.3 VS1 in otherconfigurations, up to the maximumallowable speed for the configurationbeing investigated, in the takeoff, climb,cruise, and approach configurations. Forthe landing configuration, the powermust be that necessary to maintain a 3degree angle of descent in coordinatedflight. The static lateral stability mustnot be negative at 1.2 VS1 in the takeoffconfiguration, or at 1.3 VS1 in otherconfigurations. The angle of sideslip forthese tests must be appropriate to thetype of airplane, but in no case may theconstant heading sideslip angle be lessthan that obtainable with a 10 degreebank, or if less, the maximum bankangle obtainable with full rudderdeflection or 150 pound rudder force.

(c) Paragraph (b) of this section doesnot apply to acrobatic category airplanescertificated for inverted flight.

(d) In straight, steady slips at 1.2 VS1

for any landing gear and flap positions,and for any symmetrical powerconditions up to 50 percent ofmaximum continuous power, theaileron and rudder control movementsand forces must increase steadily, butnot necessarily in constant proportion,as the angle of sideslip is increased upto the maximum appropriate to the typeof airplane. At larger slip angles, up tothe angle at which full rudder or aileroncontrol is used or a control force limit


contained in § 23.143 is reached, theaileron and rudder control movementsand forces must not reverse as the angleof sideslip is increased. Rapid entryinto, and recovery from, a maximumsideslip considered appropriate for theairplane must not result inuncontrollable flight characteristics.


§ 23.201 Wings level stall.(a) It must be possible to produce and

to correct roll by unreversed use of therolling control and to produce and tocorrect yaw by unreversed use of thedirectional control, up to the time theairplane stalls.

(b) The wings level stallcharacteristics must be demonstrated inflight as follows. Starting from a speedat least 10 knots above the stall speed,the elevator control must be pulled backso that the rate of speed reduction willnot exceed one knot per second until astall is produced, as shown by either:

(1) An uncontrollable downwardpitching motion of the airplane;

(2) A downward pitching motion ofthe airplane that results from theactivation of a stall avoidance device(for example, stick pusher); or

(3) The control reaching the stop.(c) Normal use of elevator control for

recovery is allowed after the downwardpitching motion of paragraphs (b)(1) or(b)(2) of this section has unmistakablybeen produced, or after the control hasbeen held against the stop for not lessthan the longer of two seconds or thetime employed in the minimum steadyslight speed determination of § 23.49.

(d) During the entry into and therecovery from the maneuver, it must bepossible to prevent more than 15degrees of roll or yaw by the normal useof controls.

(e) Compliance with the requirementsof this section must be shown under thefollowing conditions:

(1) Wing flaps. Retracted, fullyextended, and each intermediate normaloperating position.

(2) Landing gear. Retracted andextended.

(3) Cowl flaps. Appropriate toconfiguration.

(4) Power:(i) Power off; and(ii) 75 percent of maximum

continuous power. However, if thepower-to-weight ratio at 75 percent ofmaximum continuous power result inextreme nose-up attitudes, the test maybe carried out with the power requiredfor level flight in the landingconfiguration at maximum landingweight and a speed of 1.4 VSO, exceptthat the power may not be less than 50percent of maximum continuous power.

(5) Trim. The airplane trimmed at aspeed as near 1.5 VS1 as practicable.

(6) Propeller. Full increase r.p.m.position for the power off condition.

34. Section 23.203 is amended byrevising the section heading andintroductory text, paragraph (a), theintroductory text of paragraph (b),paragraphs (b)(4) and (b)(5), theintroductory text of paragraph (c), andparagraphs (c)(1) and (c)(4), and byadding new paragraphs (b)(6) and (c)(6)to read as follows:

§ 23.203 Turning flight and acceleratedturning stalls.

Turning flight and accelerated turningstalls must be demonstrated in tests asfollows:

(a) Establish and maintain acoordinated turn in a 30 degree bank.Reduce speed by steadily andprogressively tightening the turn withthe elevator until the airplane is stalled,as defined in § 23.201(b). The rate ofspeed reduction must be constant,and—

(1) For a turning flight stall, may notexceed one knot per second; and

(2) For an accelerated turning stall, be3 to 5 knots per second with steadilyincreasing normal acceleration.

(b) After the airplane has stalled, asdefined in § 23.201(b), it must bepossible to regain wings level flight bynormal use of the flight controls, butwithout increasing power and without—* * * * *

(4) Exceeding a bank angle of 60degrees in the original direction of theturn or 30 degrees in the oppositedirection in the case of turning flightstalls;

(5) Exceeding a bank angle of 90degrees in the original direction of theturn or 60 degrees in the oppositedirection in the case of acceleratedturning stalls; and

(6) Exceeding the maximumpermissible speed or allowable limitload factor.

(c) Compliance with the requirementsof this section must be shown under thefollowing conditions:

(1) Wing flaps: Retracted, fullyextended, and each intermediate normaloperating position;* * * * *

(4) Power:(i) Power off; and(ii) 75 percent of maximum

continuous power. However, if thepower-to-weight ratio at 75 percent ofmaximum continuous power results inextreme nose-up attitudes, the test maybe carried out with the power requiredfor level flight in the landingconfiguration at maximum landingweight and a speed of 1.4 VSO, except

that the power may not be less than 50percent of maximum continuous power.* * * * *

(6) Propeller. Full increase rpmposition for the power off condition.

§ 23.205 [Removed]35. Section 23.205 is removed.36. Section 23.207 is amended by

revising paragraphs (c) and (d), and byadding new paragraphs (e) and (f) toread as follows:

§ 23.207 Stall warning.

* * * * *(c) During the stall tests required by

§ 23.201(b) and § 23.203(a)(1), the stallwarning must begin at a speedexceeding the stalling speed by a marginof not less than 5 knots and mustcontinue until the stall occurs.

(d) When following proceduresfurnished in accordance with § 23.1585,the stall warning must not occur duringa takeoff with all engines operating, atakeoff continued with one engineinoperative, or during an approach tolanding.

(e) During the stall tests required by§ 23.203(a)(2), the stall warning mustbegin sufficiently in advance of the stallfor the stall to be averted by pilot actiontaken after the stall warning first occurs.

(f) For acrobatic category airplanes, anartificial stall warning may be mutable,provided that it is armed automaticallyduring takeoff and rearmedautomatically in the approachconfiguration.


§ 23.221 Spinning.(a) Normal category airplanes. A

single-engine, normal category airplanemust be able to recover from a one-turnspin or a three-second spin, whichevertakes longer, in not more than oneadditional turn after initiation of thefirst control action for recovery, ordemonstrate compliance with theoptional spin resistant requirements ofthis section.

(1) The following apply to one turn orthree second spins:

(i) For both the flaps-retracted andflaps-extended conditions, theapplicable airspeed limit and positivelimit maneuvering load factor must notbe exceeded;

(ii) No control forces or characteristicencountered during the spin or recoverymay adversely affect prompt recovery;

(iii) It must be impossible to obtainunrecoverable spins with any use of theflight or engine power controls either atthe entry into or during the spin; and

(iv) For the flaps-extended condition,the flaps may be retracted during the


recovery but not before rotation hasceased.

(2) At the applicant’s option, theairplane may be demonstrated to be spinresistant by the following:

(i) During the stall maneuvercontained in § 23.201, the pitch controlmust be pulled back and held againstthe stop. Then, using ailerons andrudders in the proper direction, it mustbe possible to maintain wings-levelflight within 15 degrees of bank and toroll the airplane from a 30 degree bankin one direction to a 30 degree bank inthe other direction;

(ii) Reduce the airplane speed usingpitch control at a rate of approximatelyone knot per second until the pitchcontrol reaches the stop; then, with thepitch control pulled back and heldagainst the stop, apply full ruddercontrol in a manner to promote spinentry for a period of seven seconds orthrough a 360 degree heading change,whichever occurs first. If the 360 degreeheading change is reached first, it musthave taken no fewer than four seconds.This maneuver must be performed firstwith the ailerons in the neutral position,and then with the ailerons deflectedopposite the direction of turn in themost adverse manner. Power andairplane configuration must be set inaccordance with § 23.201(e) withoutchange during the maneuver. At the endof seven seconds or a 360 degreeheading change, the airplane mustrespond immediately and normally toprimary flight controls applied to regaincoordinated, unstalled flight withoutreversal of control effect and withoutexceeding the temporary control forcesspecified by § 23.143(c); and

(iii) Compliance with §§ 23.201 and23.203 must be demonstrated with theairplane in uncoordinated flight,corresponding to one ball widthdisplacement on a slip-skid indicator,unless one ball width displacementcannot be obtained with full rudder, inwhich case the demonstration must bewith full rudder applied.

(b) Utility category airplanes. A utilitycategory airplane must meet therequirements of paragraph (a) of thissection. In addition, the requirements ofparagraph (c) of this section and§ 23.807(b)(7) must be met if approvalfor spinning is requested.

(c) Acrobatic category airplanes. Anacrobatic category airplane must meetthe spin requirements of paragraph (a)of this section and § 23.807(b)(6). Inaddition, the following requirementsmust be met in each configuration forwhich approval for spinning isrequested:

(1) The airplane must recover fromany point in a spin up to and including

six turns, or any greater number of turnsfor which certification is requested, innot more than one and one-halfadditional turns after initiation of thefirst control action for recovery.However, beyond three turns, the spinmay be discontinued if spiralcharacteristics appear.

(2) The applicable airspeed limits andlimit maneuvering load factors must notbe exceeded. For flaps-extendedconfigurations for which approval isrequested, the flaps must not beretracted during the recovery.

(3) It must be impossible to obtainunrecoverable spins with any use of theflight or engine power controls either atthe entry into or during the spin.

(4) There must be no characteristicsduring the spin (such as excessive ratesof rotation or extreme oscillatorymotion) that might prevent a successfulrecovery due to disorientation orincapacitation of the pilot.

38. Section 23.233(a) is revised toread as follows:

§ 23.233 Directional stability and control.(a) A 90 degree cross-component of

wind velocity, demonstrated to be safefor taxiing, takeoff, and landing must beestablished and must be not less than0.2 VSO.* * * * *


§ 23.235 Operation on unpaved surfaces.The airplane must be demonstrated to

have satisfactory characteristics and theshock-absorbing mechanism must notdamage the structure of the airplanewhen the airplane is taxied on theroughest ground that may reasonably beexpected in normal operation and whentakeoffs and landings are performed onunpaved runways having the roughestsurface that may reasonably be expectedin normal operation.

40. A new § 23.237 is added to readas follows:

§ 23.237 Operation on water.A wave height, demonstrated to be

safe for operation, and any necessarywater handling procedures for seaplanesand amphibians must be established.

§ 23.253 [Amended]41. Section 23.253 is amended by

removing paragraph (b)(1) and byredesignating paragraphs (b)(2) and(b)(3) as paragraphs (b)(1) and (b)(2),respectively.

42. Section 23.562(d) introductorytext is revised to read as follows:

§ 23.562 Emergency landing dynamicconditions.

* * * * *

(d) For all single-engine airplaneswith a VSO of more than 61 knots atmaximum weight, and thosemultiengine airplanes of 6,000 poundsor less maximum weight with a VSO ofmore than 61 knots at maximum weightthat do not comply with § 23.67(a)(1);* * * * *

43. Section 23.1325 is amended byrevising paragraph (e), by removing andreserving paragraph (f) to read asfollows:

§ 23.1325 Static pressure system.

* * * * *(e) Each static pressure system must

be calibrated in flight to determine thesystem error. The system error, inindicated pressure altitude, at sea-level,with a standard atmosphere, excludinginstrument calibration error, may notexceed ±30 feet per 100 knot speed forthe appropriate configuration in thespeed range between 1.3 VS0 with flapsextended, and 1.8 VS1 with flapsretracted. However, the error need notbe less than 30 feet.

(f) [Reserved]* * * * *

44. Section 23.1511 is amended byrevising paragraphs (a)(1) and (a)(2) toread as follows:

§ 23.1511 Flap extended speed.(a) * * *(1) Not less than the minimum value

of VF allowed in § 23.345(b); and(2) Not more than VF established

under § 23.345(a), (c), and (d).* * * * *

45. Section 23.1521 is amended byrevising paragraphs (b)(5) and (e) to readas follows:

§ 23.1521 Powerplant limitations.

* * * * *(b) * * *(5) The maximum allowable cylinder

head (as applicable), liquid coolant andoil temperatures.* * * * *

(e) Ambient temperature. For allairplanes except reciprocating engine-powered airplanes of 6,000 pounds orless maximum weight, ambienttemperature limitations (includinglimitations for winterizationinstallations if applicable) must beestablished as the maximum ambientatmospheric temperature at whichcompliance with the cooling provisionsof §§ 23.1041 through 23.1047 is shown.

46. Section 23.1543(c) is added toread as follows:

§ 23.1543 Instrument markings: General.

* * * * *(c) All related instruments must be

calibrated in compatible units.


47. Section 23.1545 is amended byrevising paragraphs (b)(5) and (b)(6) toread as follows:

§ 23.1545 Airspeed indicator.

* * * * *(b) * * *(5) For reciprocating multiengine-

powered airplanes of 6,000 pounds orless maximum weight, for the speed atwhich compliance has been shown with§ 23.69(b) relating to rate of climb atmaximum weight and at sea level, ablue radial line.

(6) For reciprocating multiengine-powered airplanes of 6,000 pounds orless maximum weight, for the maximumvalue of minimum control speed, VMC,(one-engine-inoperative) determinedunder § 23.149(b), a red radial line.* * * * *


§ 23.1553 Fuel quantity indicator.

A red radial line must be marked oneach indicator at the calibrated zeroreading, as specified in § 23.1337(b)(1).

49. Section 23.1555(e)(2) is revised toread as follows:

§ 23.1555 Control markings.

* * * * *(e) * * *(2) Each emergency control must be

red and must be marked as to methodof operation. No control other than anemergency control, or a control thatserves an emergency function inaddition to its other functions, shall bethis color.


§ 23.1559 Operating limitations placard.

(a) There must be a placard in clearview of the pilot stating—

(1) That the airplane must be operatedin accordance with the Airplane FlightManual; and

(2) The certification category of theairplane to which the placards apply.

(b) For airplanes certificated in morethan one category, there must be aplacard in clear view of the pilot statingthat other limitations are contained inthe Airplane Flight Manual.

(c) There must be a placard in clearview of the pilot that specifies the kindof operations to which the operation ofthe airplane is limited or from which itis prohibited under § 23.1525.

51. Section 23.1563(c) is added toread as follows:

§ 23.1563 Airspeed placards.

* * * * *(c) For reciprocating multiengine-

powered airplanes of more than 6,000

pounds maximum weight, and turbineengine-powered airplanes, themaximum value of the minimumcontrol speed, VMC (one-engine-inoperative) determined under§ 23.149(b).

52. Section 23.1567(d) is added toread as follows:

§ 23.1567 Flight maneuver placard.* * * * *

(d) For acrobatic category airplanesand utility category airplanes approvedfor spinning, there must be a placard inclear view of the pilot—

(1) Listing the control actions forrecovery from spinning maneuvers; and

(2) Stating that recovery must beinitiated when spiral characteristicsappear, or after not more than six turnsor not more than any greater number ofturns for which the airplane has beencertificated.

53. Section 23.1581 is amended byadding new paragraphs (a)(3) and (c),and by revising the introductory text ofparagraph (b)(2) and paragraph (d) toread as follows:

§ 23.1581 General.(a) * * *(3) Further information necessary to

comply with the relevant operatingrules.

(b) * * *(2) The requirements of paragraph

(b)(1) of this section do not apply toreciprocating engine-powered airplanesof 6,000 pounds or less maximumweight, if the following is met:* * * * *

(c) The units used in the AirplaneFlight Manual must be the same as thosemarked on the appropriate instrumentsand placards.

(d) All Airplane Flight Manualoperational airspeeds, unless otherwisespecified, must be presented asindicated airspeeds.* * * * *

54. Section 23.1583 is amended byrevising the introductory text, andparagraphs (a)(3) introductory text,(a)(3)(i), (c)(3), (c)(4), (d), (e), (f), and (g);by redesignating paragraphs (k), (l), and(m) as paragraphs (i), (j), and (k),respectively, and revising them; and byadding new paragraphs (c)(5), (c)(6), (l),(m), (n), (o), and (p) to read as follows:

§ 23.1583 Operating limitations.The Airplane Flight Manual must

contain operating limitationsdetermined under this part 23,including the following—

(a) * * *(3) In addition, for turbine powered

commuter category airplanes—(i) The maximum operating limit

speed, VMO/MMO and a statement that

this speed must not be deliberatelyexceeded in any regime of flight (climb,cruise or descent) unless a higher speedis authorized for flight test or pilottraining;* * * * *

(c) * * *(3) For normal, utility, and acrobatic

category reciprocating engine-poweredairplanes of more than 6,000 poundsmaximum weight and for turbineengine-powered airplanes in the normal,utility, and acrobatic category,performance operating limitations asfollows—

(i) The maximum takeoff weight foreach airport altitude and ambienttemperature within the range selectedby the applicant at which the airplanecomplies with the climb requirements of§ 23.63(c)(1).

(ii) The maximum landing weight foreach airport altitude and ambienttemperature within the range selectedby the applicant at which the airplanecomplies with the climb requirements of§ 23.63(c)(2).

(4) For commuter category airplanes,the maximum takeoff weight for eachairport altitude and ambienttemperature within the range selectedby the applicant at which—

(i) The airplane complies with theclimb requirements of § 23.63(d)(1); and

(ii) The accelerate-stop distancedetermined under § 23.55 is equal to theavailable runway length plus the lengthof any stopway, if utilized; and either:

(iii) The takeoff distance determinedunder § 23.59(a) is equal to the availablerunway length; or

(iv) At the option of the applicant, thetakeoff distance determined under§ 23.59(a) is equal to the availablerunway length plus the length of anyclearway and the takeoff run determinedunder § 23.59(b) is equal to the availablerunway length.

(5) For commuter category airplanes,the maximum landing weight for eachairport altitude within the rangeselected by the applicant at which—

(i) The airplane complies with theclimb requirements of § 23.63(d)(2) forambient temperatures within the rangeselected by the applicant; and

(ii) The landing distance determinedunder § 23.75 for standard temperaturesis equal to the available runway length.

(6) The maximum zero wing fuelweight, where relevant, as established inaccordance with § 23.343.

(d) Center of gravity. The establishedcenter of gravity limits.

(e) Maneuvers. The followingauthorized maneuvers, appropriateairspeed limitations, and unauthorizedmaneuvers, as prescribed in this section.


(1) Normal category airplanes. Noacrobatic maneuvers, including spins,are authorized.

(2) Utility category airplanes. A list ofauthorized maneuvers demonstrated inthe type flight tests, together withrecommended entry speeds and anyother associated limitations. No othermaneuver is authorized.

(3) Acrobatic category airplanes. Alist of approved flight maneuversdemonstrated in the type flight tests,together with recommended entryspeeds and any other associatedlimitations.

(4) Acrobatic category airplanes andutility category airplanes approved forspinning. Spin recovery procedureestablished to show compliance with§ 23.221(c).

(5) Commuter category airplanes.Maneuvers are limited to any maneuverincident to normal flying, stalls, (exceptwhip stalls) and steep turns in whichthe angle of bank is not more than 60degrees.

(f) Maneuver load factor. The positivelimit load factors in g’s, and, inaddition, the negative limit load factorfor acrobatic category airplanes.

(g) Minimum flight crew. The numberand functions of the minimum flightcrew determined under § 23.1523.* * * * *

(i) Maximum operating altitude. Themaximum altitude established under§ 23.1527.

(j) Maximum passenger seatingconfiguration. The maximum passengerseating configuration.

(k) Allowable lateral fuel loading. Themaximum allowable lateral fuel loadingdifferential, if less than the maximumpossible.

(l) Baggage and cargo loading. Thefollowing information for each baggageand cargo compartment or zone—

(1) The maximum allowable load; and(2) The maximum intensity of

loading.(m) Systems. Any limitations on the

use of airplane systems and equipment.(n) Ambient temperatures. Where

appropriate, maximum and minimumambient air temperatures for operation.

(o) Smoking. Any restrictions onsmoking in the airplane.

(p) Types of surface. A statement ofthe types of surface on which operationsmay be conducted. (See § 23.45(g) and§ 23.1587 (a)(4), (c)(2), and (d)(4)).


§ 23.1585 Operating procedures.(a) For all airplanes, information

concerning normal, abnormal (ifapplicable), and emergency proceduresand other pertinent information

necessary for safe operation and theachievement of the scheduledperformance must be furnished,including—

(1) An explanation of significant orunusual flight or ground handlingcharacteristics;

(2) The maximum demonstratedvalues of crosswind for takeoff andlanding, and procedures andinformation pertinent to operations incrosswinds;

(3) A recommended speed for flight inrough air. This speed must be chosen toprotect against the occurrence, as aresult of gusts, of structural damage tothe airplane and loss of control (forexample, stalling);

(4) Procedures for restarting anyturbine engine in flight, including theeffects of altitude; and

(5) Procedures, speeds, andconfiguration(s) for making a normalapproach and landing, in accordancewith §§ 23.73 and 23.75, and atransition to the balked landingcondition.

(6) For seaplanes and amphibians,water handling procedures and thedemonstrated wave height.

(b) In addition to paragraph (a) of thissection, for all single-engine airplanes,the procedures, speeds, andconfiguration(s) for a glide followingengine failure, in accordance with§ 23.71 and the subsequent forcedlanding, must be furnished.

(c) In addition to paragraph (a) of thissection, for all multiengine airplanes,the following information must befurnished:

(1) Procedures, speeds, andconfiguration(s) for making an approachand landing with one engineinoperative;

(2) Procedures, speeds, andconfiguration(s) for making a balkedlanding with one engine inoperative andthe conditions under which a balkedlanding can be performed safely, or awarning against attempting a balkedlanding;

(3) The VSSE determined in § 23.149;and

(4) Procedures for restarting anyengine in flight including the effects ofaltitude.

(d) In addition to paragraphs (a) andeither (b) or (c) of this section, asappropriate, for all normal, utility, andacrobatic category airplanes, thefollowing information must befurnished:

(1) Procedures, speeds, andconfiguration(s) for making a normaltakeoff, in accordance with § 23.51 (a)and (b), and § 23.53 (a) and (b), and thesubsequent climb, in accordance with§ 23.65 and § 23.69(a).

(2) Procedures for abandoning atakeoff due to engine failure or othercause.

(e) In addition to paragraphs (a), (c),and (d) of this section, for all normal,utility, and acrobatic categorymultiengine airplanes, the informationmust include the following:

(1) Procedures and speeds forcontinuing a takeoff following enginefailure and the conditions under whichtakeoff can safely be continued, or awarning against attempting to continuethe takeoff.

(2) Procedures, speeds, andconfigurations for continuing a climbfollowing engine failure, after takeoff, inaccordance with § 23.67, or enroute, inaccordance with § 23.69(b).

(f) In addition to paragraphs (a) and(c) of this section, for commutercategory airplanes, the information mustinclude the following:

(1) Procedures, speeds, andconfiguration(s) for making a normaltakeoff.

(2) Procedures and speeds for carryingout an accelerate-stop in accordancewith § 23.55.

(3) Procedures and speeds forcontinuing a takeoff following enginefailure in accordance with § 23.59(a)(1)and for following the flight pathdetermined under § 23.57 and§ 23.61(a).

(g) For multiengine airplanes,information identifying each operatingcondition in which the fuel systemindependence prescribed in § 23.953 isnecessary for safety must be furnished,together with instructions for placingthe fuel system in a configuration usedto show compliance with that section.

(h) For each airplane showingcompliance with § 23.1353 (g)(2) or(g)(3), the operating procedures fordisconnecting the battery from itscharging source must be furnished.

(i) Information on the total quantity ofusable fuel for each fuel tank, and theeffect on the usable fuel quantity, as aresult of a failure of any pump, must befurnished.

(j) Procedures for the safe operation ofthe airplane’s systems and equipment,both in normal use and in the event ofmalfunction, must be furnished.


§ 23.1587 Performance information.Unless otherwise prescribed,

performance information must beprovided over the altitude andtemperature ranges required by§ 23.45(b).

(a) For all airplanes, the followinginformation must be furnished—

(1) The stalling speeds VSO and VS1

with the landing gear and wing flaps


retracted, determined at maximumweight under § 23.49, and the effect onthese stalling speeds of angles of bankup to 60 degrees;

(2) The steady rate and gradient ofclimb with all engines operating,determined under § 23.69(a);

(3) The landing distance, determinedunder § 23.75 for each airport altitudeand standard temperature, and the typeof surface for which it is valid;

(4) The effect on landing distances ofoperation on other than smooth hardsurfaces, when dry, determined under§ 23.45(g); and

(5) The effect on landing distances ofrunway slope and 50 percent of theheadwind component and 150 percentof the tailwind component.

(b) In addition to paragraph (a) of thissection, for all normal, utility, andacrobatic category reciprocating engine-powered airplanes of 6,000 pounds orless maximum weight, the steady angleof climb/descent, determined under§ 23.77(a), must be furnished.

(c) In addition to paragraphs (a) and(b) of this section, if appropriate, fornormal, utility, and acrobatic categoryairplanes, the following informationmust be furnished—

(1) The takeoff distance, determinedunder § 23.53 and the type of surface forwhich it is valid.

(2) The effect on takeoff distance ofoperation on other than smooth hardsurfaces, when dry, determined under§ 23.45(g);

(3) The effect on takeoff distance ofrunway slope and 50 percent of theheadwind component and 150 percentof the tailwind component;

(4) For multiengine reciprocatingengine-powered airplanes of more than

6,000 pounds maximum weight andmultiengine turbine powered airplanes,the one-engine-inoperative takeoffclimb/descent gradient, determinedunder § 23.66;

(5) For multiengine airplanes, theenroute rate and gradient of climb/descent with one engine inoperative,determined under § 23.69(b); and

(6) For single-engine airplanes, theglide performance determined under§ 23.71.

(d) In addition to paragraph (a) of thissection, for commuter categoryairplanes, the following informationmust be furnished—

(1) The accelerate-stop distancedetermined under § 23.55;

(2) The takeoff distance determinedunder § 23.59(a);

(3) At the option of the applicant, thetakeoff run determined under § 23.59(b);

(4) The effect on accelerate-stopdistance, takeoff distance and, ifdetermined, takeoff run, of operation onother than smooth hard surfaces, whendry, determined under § 23.45(g);

(5) The effect on accelerate-stopdistance, takeoff distance, and ifdetermined, takeoff run, of runwayslope and 50 percent of the headwindcomponent and 150 percent of thetailwind component;

(6) The net takeoff flight pathdetermined under § 23.61(b);

(7) The enroute gradient of climb/descent with one engine inoperative,determined under § 23.69(b);

(8) The effect, on the net takeoff flightpath and on the enroute gradient ofclimb/descent with one engineinoperative, of 50 percent of theheadwind component and 150 percentof the tailwind component;

(9) Overweight landing performanceinformation (determined byextrapolation and computed for therange of weights between the maximumlanding and maximum takeoff weights)as follows—

(i) The maximum weight for eachairport altitude and ambienttemperature at which the airplanecomplies with the climb requirements of§ 23.63(d)(2); and

(ii) The landing distance determinedunder § 23.75 for each airport altitudeand standard temperature.

(10) The relationship between IASand CAS determined in accordance with§ 23.1323 (b) and (c).

(11) The altimeter system calibrationrequired by § 23.1325(e).

57. Section 23.1589(b) is revised toread as follows:

§ 23.1589 Loading information.

* * * * *(b) Appropriate loading instructions

for each possible loading conditionbetween the maximum and minimumweights established under § 23.25, tofacilitate the center of gravity remainingwithin the limits established under§ 23.23.

Appendix E to Part 23 [Removed andReserved]

58. Appendix E to Part 23 is removedand reserved.

Issued in Washington, DC, on January 29,1996.David R. Hinson,Administrator.[FR Doc. 96–2082 Filed 2–8–96; 8:45 am]BILLING CODE 4910–13–M

federal register /vol. 61, no. 28/friday, february 9, … · from a bunsen or tirrill burner must...

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