Cus tomer Se r v i ce s

Issue 4 March 2003

WingtipsI n f o r m a t i o n t o S a a b 3 4 0 a n d S a a b 2 0 0 0 O p e r a t o r s

S A A B A I R C R A F T

State of thecompany

Focus onoperations

20 Years of theSaab 340

www.saabaircraft.com

M E S S A G EF RO M

Contents

Saab 340 marks 20th anniversary . . . . . . . . . . . . . . . . . . . . . 3

State of the Saab Aircraft Company . . . . . . . . . . . . . . . . . . . 4by Hans Almér, President Saab Aircraft AB

The environmentally friendly Saab 340 and Saab 2000 . . . . . . 5by Lennart Ericsson, Senior Engineer Aerodynamics-OperationsEngineering

Saab 340 questions from the fleet . . . . . . . . . . . . . . . . . . . 6-7by Captain Bob Roth, Flight Operations

Saab 2000 Operators’ Conference . . . . . . . . . . . . . . . . . . . . 8

TAWS update . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 8by Per Skogsberg, Sales Manager, Modifications

Flexible logistic solutions to fit any operation . . . . . . . . . . . .8

Structural design and maintenance principles . . . . . . . . . . . . 9by George Caracost, Customer Service Director.

Maintaining aircraft performance . . . . . . . . . . . . . . . . . . 10-11by Joakim Andersson, Manager, Aerodynamics-Operations Engineering

Management changes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 11

Saab operators . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12

Wingtips is published by Saab Aircraft AB

Editor : Kelly MurphyEmerald Media usemerald@aol.comEurope: Alison ChambersEmerald Media alison@emeraldmedia.co.uk

Design and Layout:Aeris Graphic Design jenaeris@aol.com

Printed in USA March 2003©2003 Saab Aircraft AB

John Belanger

Welcome to the first issue of Wingtips for 2003!

Normally in this section you would find a greeting from Hans Almér andMarty Schultz with some well chosen words summarizing Saab’s suppor tactivit ies towards our customers and the market place in general.However, in this first issue of 2003 we have instead chosen to expandthat summary into a ful l ar tic le and provide the president of SaabAircraft AB the oppor tunity to comment in detail. You will find the special“State of the Saab Aircraft Company” address on page 4 of this issue .

That leaves it up to me to fill this space and to fill you in on this issue—and I’l l do my best!

In addition to the above , this issue marks a milestone in the Saab 340stor y—namely the fact that we are celebrating 20 years of Saab 340service this year. The workhorse of the regional aircraft f leet is nowofficially a veteran—and stil l going strong. You’ll find an ar tic le coveringthe bir th of the 340 on page 3. It will be a topic that we will continueto touch on both in future Wingtips issues as well as in Saab AircraftLeasing’s Market Repor t during the coming year.

Wingtips is tradit ionally an information source for the fl ight andmaintenance folks who operate and maintain our aircraft, so of coursethere is , as always, technical and operational information and tips that wehope will be of interest and assistance. Towards this end, look for several“Ops” oriented ar tic les .

In closing, and since this is my first opportunity to address the readers ofWingtips personally, I would like to both introduce myself to those of youwho I have not as yet had the oppor tunity to meet, as well as take thechance to give my warmest regards to those of our operators and vendorswho I have met and worked with over the years .

It has been about two years now since my transit ion from a technicalposit ion within the company into PR and Communications . While thechange in my work-related responsibilities has been rather dramatic , after12–plus years with Saab Aircraft, I st i l l find the interaction with ourcustomers , suppliers and others to be as stimulating and rewarding nowas I did dur ing my earl iest days at Saab Aircraft. I look forward tomeeting even more of you in my current position and to many more goodyears as par t of the Saab Family.

Good Reading!

John BelangerDirector, PR and Communications

Saab Aviation ServicesSE-581 88 LinköpingSwedenTel: +46 13 18 2616 Fax: +46 13 18 4495e-mail: aviationservices@saab.sewww.saab.se

Saab Aircraft ABSE-581 88 Linköping, SwedenTelephone: +46 13 18 2616Telefax: +46 13 18 4495e-mail: customer.support@saabaircraft.com

Saab Aircraft of America LLC21300 Ridgetop CircleSterling,Virginia 20166 U.S.ATelephone: +1 703 406 7200Fax +1 703 406 7222e-mail: customer.support@saaius.com

www.saabaircraft.com

W i n g t i p s M a r c h 2 0 0 3 3

Cus tomer Se r v i ce s

The year 2003 marks the 20th anniversaryof the Saab 340. In this time, the aircrafthas earned the reputation of being areliable, dependable workhorse capable ofoperating in a diverse range of conditionsfrom the frozen winters of Scandinavia tothe hot, dusty and frequently stonylandscapes of South America. The aircrafthas carried VIP’s (the Pope in June 1984)as well as freight in the newly configureddedicated cargo version. The Saab 340 isequally at home plying the runways ofmajor international airports or rarely usedairways providing essential links to remotecommunities.

Having ‘rolled out’ in front of anaudience of a thousand people on October27, 1982, prototype serial number 001 ofthe Saab-Fairchild 340A, as it was thenknown, made its tentative, maidenflight in January 1983 from its homebase in Linköping, Sweden. Aircraft 001 is,incidentally, famous for the signature on itsfuselage, personally inscribed by King CarlXVI Gustaf and can still be seen today,painted in Skyways colors ‘flying’ atop apost on the outskirts of Linköping. This isa proud monument to Saab’s historic linkswith the city.

A rigorous flight test program waslaunched with the first 24 flightscompleted in just four weeks. Serialnumber 002 followed in April of that year,just in time to make its debut at the ParisAir Show in June, before returning toSweden to join the flight test program andthen on to conduct hot and high trials inTerrejon, near Madrid in Spain in the July.It remained as a test aircraft for ongoingdevelopment trials leading up to the

launch of the B series. The third prototype,serial number 003, joined the test fleetsoon after, allowing the program to fulfillits planned schedule on time.

The Saab 340 was way ahead of itstime and the first, by a long margin, of awhole new generation of regional airlines.It demonstrated the incredible faith felt bythe Board of Saab-Scania and its thenpartners Fairchild Industries and GeneralElectric. It was also the first aircraft ever towork towards Joint European Certification,JAR 25, previously the responsibility ofindividual countries. This was no mean featand required a total of 35,000 man-hoursand 1,731 test flights, of which 585 hourswere certification tests.

The program was no pie-in-the-sky.Regional airlines around the world sawthe potential in this revolutionary newregional aircraft and were active,sometimes even vociferous, in their inputand recommendations. Legend recordsthat Moritz Suter, then President andCEO of Switzerland’sCrossair (and worldwidelaunch customer), declared‘You build it and I’ll buy 50,’which he eventually did!

It was also in 1983 thatCincinnati-based Comairannounced to the worldthat it would be the firstUS carrier to put the 340into service. They were not,however, the US launchcustomer for this mould-breaking little airliner.That accolade goes to AirMidwest whose President

and founder, Gary Adamson, signed up forfive of the type in 1981.

Since those heady days, much haschanged in the world of aviation, but onething has remained constant: The Saab340. With over 10 million flights to itscredit to date, it has proven itself to be avenerable workhorse and can be foundproviding a vital service in every corner ofthe world. A veteran perhaps, but a reliableone with many more years still to enjoy.

Wing t ip s

Saab marks 20thanniversaryThe first tentative steps

Saab 340 Roll Out

Saab 340 Joint Certification

W i n g t i p s M a r c h 2 0 0 34

As w ee n t e rw h a t

appears to beyet anotheryear of uncer-tainty in theav ia t ion in-dustry, I’d liketo take theopportunity to

share my views about the future of SaabAircraft and our market place in general.

With the challenges the industry hasfaced over the last few years, and iscontinuing to face, also come opportunities.We have the chance, as well as the need, tore-examine how we do business, take stockof our operations and to examine freshideas. Above all, to remember howimportant it is to listen to our customersand be responsive to their needs.

Airlines across the board are findingmargins getting tighter and tighter, makingit imperative that OEMs and supplierswork even closer with them to improvereliability and shorten lead times. Here atSaab we believe that we are adapting tothe changing scenario by building in evenmore flexibility to our systems andbusinesses, increasing our responsecapability in shorter time-frames andtailoring the level of support according toeach individual customers needs.

It goes without saying that the size ofthe Saab fleet remains more or lessconstant. However the trend, especially inthe US market, is moving toward morecustomers operating smaller fleets. Andwith smaller fleet sizes operating withfewer in-house resources, comes anincreased need for support. It is not viablefor operators with six or seven aircraft intheir fleet to have a full maintenance and

engineering capability, or a full complementof spares. This is where Saab’s tailoredsupport service comes into its own.

Many of our operators are also new tothe type, again requiring a higher level ofsupport from Saab, particularly during theintegration stage. In some ways it isreminiscent of the early days, some 19 or 20years ago, when all our customers were newto the type, requiring high levels of supportper aircraft, particularly during start up.

These days, it is also frequently thecase that the Saab operation is a move upfrom 19-seaters, in an environment withlittle infrastructure to support the enlargedoperation. It is in these cases that Saab’sexpertise and experience really comes tothe fore. An expanded and continuouslyrefined set of tools, such as the recentlyintroduced web portal which allowsoperators to easily order spares, lodgereports or simply ask for advice, make iteasier for maintenance personnel to keeptheir aircraft where they belong—in the air.

Although already renowned forreliability, Saab recognizes the need to offermore practical solutions. We are expandingactivities under JAR 145 approval toundertake more maintenance, more heavychecks and refurbishment programs. Stepshave also been taken to reduce lead times,further increase aircraft system reliabilityand to improve and augment our alreadysuperior logistics support with arestructured PEP solution and the newREPOS program, offered in conjunctionwith Saab Aviocomp that was recentlyintroduced (see related article on page 8).

Training is high on the agenda too,with JAR 147 approvals currently beingsought for European operations. Approvalby Transport Canada for mechanic typetraining has already been won, giving usthe ability to provide factory training inthat growing marketplace.

New and impending regulations areadding even more of a burden to the hard-pressed independent regional operator. Butagain, Saab is working on cost-effectivesolutions to ensure that our customers arecompliant in good time. In co-operation

with UK-based AIM, secure cockpit doorshave been developed. Deliveries andinstallation of the new doors are expected tobe completed in good time to meet the earlyApril 2003 deadline. Evaluations of the fueltank safety issue were submitted last year,and the implementation and integration ofTAWS has also been addressed.

Further ahead, we are working on theproposed reduced vertical separation over29,000 feet for Saab 2000 operations. We arealso continuously updating studies on otherpotential future requirements. Our intention isto always be proactive and to have a solutionavailable and “in the box” almost before thecustomer realizes the need.

Management programs are already inplace to continue adding value to the fleet.For example, the design life of the 340 hasrecently been increased from 45,000 to60,000 hours, adding another seven toeight years of life to the aircraft. Indeed thehighest time 340 has just passed 40,000hours, which adds 10 to 15 more years toits usable life.

To make even better use of thisextended life-cycle, and in response tomarket requirements, we have also, justtwo months ago, introduced a dedicatedSaab 340A cargo version, adding greaterflexibility to its potential role.

I have not mentioned aircraft safety inthis article, at least until now. That is becauseit is a given in all of our activities. Maintainingthe airworthiness of the Saab 340 and 2000 isparamount. The Saab fleet remains among thesafest in its class, and our staff workcontinuously to ensure that it remains so. Asa company, we are active in the Flight SafetyFoundation and do our part to promote airsafety in the industry as a whole.

Much of our activity has been, and willcontinue to be, market and authoritydriven. With a fleet of over 500 aircraftflying in all corners of the globe, SaabAircraft remains committed to sustainingand further developing an infrastructurethat supports and enables the continuedoperation of the fleet which is still, by anycriteria, one of the most reliable in its field.

Wing t ip s

Saab Aircraft—The state of thecompanyby Hans Almér, President Saab Aircraft AB

Environmental impact, particularly inrelation to aircraft operations, is anissue of continual and growingimportance in our industry. On noiseand emissions from aircraft, thereare certification regulations providedthrough ICAO and FAR.

Regional aircraft in general, and theSaab 340 and Saab 2000 in particular,have low noise levels. In fact, both Saabtypes meet regulatory external noiselimits with quite a margin and are ratedfavorably with respect to engine exhaustgaseous emissions.

Noise is the environmental issuemost often associated with aircraft andwhere regulations are fully established.ICAO Annex 16 and FAR Part 36 set thestandards that evaluate noise levels atthree reference certification conditionsduring takeoff and landing. In Figure 1to the right, the improved noisereduction characteristics for regionalaircraft since 1960 are displayed. Thechart shows the cumulative effectiveperceived noise level for Takeoff (flyover),Sideline (or Lateral) and Approach andclearly demonstrates the low certificatednoise levels for the Saab 340 and Saab2000 at introduction into service.

Figure 1 has shown that the Saab2000 cumulative certification noise levelis about the same as for the smallerSaab 340. This is no surprise (to usanyway). In spite of having more thantwice the engine power of the Saab 340,the design goal for the Saab 2000 wasset early in the program to becomparable to the certificated noiselevels for the Saab 340. This was amarket requirement, albeit a tough one,as the Saab 340 had already becomeone of the quietest regional aircraft inits class. Indeed, at some small airportsthe 340 had set the criteria for noise

levels. However, with slow rotating, sweptsix-bladed propellers, relatively quietengines and a modern, full authoritydigital electronic control (FADEC) for thepropeller and engine, the design goal forthe Saab 2000 was achievable.

Noise impact around airports is also asensitive issue. Here, application of noiseabatement procedures (NAP) can have apositive effect with significant reduction ofthe noise exposure area. This is exemplifiedin Figures 2 and 3 for the 340B at takeoffand landing, respectively. The impact offlight procedures on 70 dBA footprints isshown. (Note the expanded lateral scalefor distance.) On this subject, your Saaboperations support staff can assist withmore specific information.

Ramp no i se wi th the APU inoperation is also an issue to beconsidered. In the Saab 2000, the locationof the APU in the tail cone with the inletand exhaust pointed upwards is the bestfrom a low noise signature point-of-view.Measurements around the aircraft haveshown that the design goal for ramp noise,set to five decibels below ICAO Annex 16guidelines, is met.

A Landing and Take-Off (LTO) cycle isdefined in ICAO Annex 16 for certificationof engine exhaust gaseous emissions for jetengines. This cycle has also been usedrecently to estimate emissions for non-regulated turboprop engines in orderto satisfy classification of aircraft foremissions charging schemes at airports.

In Europe, Switzerland and Swedenwere the first countries to introduceemissions-related landing charges, withthe aim of reducing specific emissionsfrom air traffic and to encourage airlines toinvest in aircraft with environmentallyfriendly engines. Based on the estimatedrelease of NOx in the LTO cycle, thecharges were expressed as a surcharge onthe landing fee ranging from zero to 30%(40% in Switzerland) in increments of 5%.In both countries, the Saab 340 and Saab2000 aircraft qualified for zero surchargeswhich no other turboprop engines incompetitive aircraft did.

W i n g t i p s M a r c h 2 0 0 3 5

The environmentally friendlySaab 340 and Saab 2000

Wing t ip s

by Lennart Ericsson, Senior Engineer Aerodynamics–Operations Engineering

Certification noise reduction characteristics of regional aircraft

250

260

270

280

290

300

1955 1960 1965 1970 1975 1980 1985 1990 1995 2000

Year of introduction

Cum

ulat

ive

cert

ifica

tion

nois

e le

vels

- E

PNdB

Jets

Props

340/2000

Ref. ERA Brochure

Annex 16 Chapter 3 Low Limit

Saab 340B/MTOW impact of Noise Abatement Procedureat takeoff70 dBA Noise Footprint

-2000

-1000

0

1000

2000

-2000 0 2000 4000 6000 8000 10000

Distance from brake release - m

Late

ral d

ista

nce

- m

Baseline procedure

NAP 140/1500 ft

Saab 340B impact of Noise Abatement Procedure at landing70 dBA Noise Footprint

-2000

-1000

0

1000

2000

-2000 0 2000 4000 6000 8000 10000

Distance to threshold - m

Late

ral d

ista

nce

– m

Max Prpm

Min/Max Prpm

Figure 1

Figure 2

Figure 3

A

QA

QAvionics

“Since the EFIS CRT’s often blank out whenthe hydraulic pump cycles, is it OK to just turnthe pump switch OFF?”

No. “Blanking” of the CRT’s caused by voltagedrop during cycling of the hydraulic pump generallycauses no damage to the CRT’s, etc. Forgetting toswitch the pump back on and taxiing into somethinghard and expensive might.

“What is a good way to shorten the life of my neat-o EFIS?”

Sitting on the flightline waiting for passengers ina static airplane with LEFT and RIGHT AVIONICSon line—especially, but not limited to, on a warmday. EFIS has been around for 20 years in regionalaircraft now (hmmm, about the time the 340appeared on the scene…), so flight attendants, co-pilots, and etc. are no longer impressed with all the sparkles in the cockpit. So, if you are not using it— turn it off—andimpress the kids with your 10,000 hours of Saab 340 flying!

W i n g t i p s M a r c h 2 0 0 36

Wing t ip s

Saab 340 questionsfrom the fleetby Captain Bob Roth, Flight Operations

This is the first of a two-part Question and Answer forum.

As we enter the Saab 340’s 20th year of flight, it seems,to paraphrase the old song; there are no new questionsunder the sun. With some questions being asked, andasked, and asked again! But quite often a brand newquestion or issue is raised and requires us to put on ourthinking caps (and sometimes the dunce cap…).

For the benefit of new members of the Saab 340 flight operations family, and for you old-timers sleeping in theback of the classroom, the following are a few recent questions received from your fellow aircrews out there in the“real world”.

By the way, please have patience if some ofthese are really old news to you. In return, wewon’t tell anyone if you’ve learned something.Enjoy!

AQ

AQ

Electrical“What is the correct method, and purpose, of the “Bus Tie

Conn” check after 2nd engine start?”

Aircrews are accustomed to confirming“warning” (or in this case,a “not normal”) lights OFF during checklists—and it has beenobserved that many crews have come to believe that after enginestart they are merely checking that the green BUS TIE CONNlight is OFF. However, while this is almost half correct, the propercheck is ensuring that the green light is ON, prior to selecting the2nd generator on line, then OFF after that generator connects.This is to ensure that the start relay has properly closed—and thusavoiding a nasty surprise if the opposite generator should laterfail.

“Maintenance control told me to place the BAT switches inOVRD recently while parked with EXT PWR ON. Is this OK?”

NO. Battery overtemp protection is NOT provided withBAT switches in OVRD. This function is intended for atheoretical emergency case only (i.e., really bad day), whereDC Generators have been lost and battery temperature(s)exceed 71 deg. C., resulting in opening of BAT relay(s).

W i n g t i p s M a r c h 2 0 0 3 7

Wing t ip s

Saab 2000 Operators’ConferenceJune 2 – 4, 2003Linköping, Sweden

Don't forget to put this date in

your diary!

The 2003 Saab 2000 Operators

Conference marks a significant

change in focus.

We plan an executive manage-

ment meeting with the goal of

bringing key personnel and decision

makers from the operators, major

vendors, and Saab Aircraft together

in an open forum. Significant

technical and operational issues will

be addressed with a focus on

integrated technical and logistics

solutions.

Invitations to the conference will

be mailed in the near future.

Contact your Saab CSD for more

detailed information.

A

Q

A

QPneumatics and ECS

“The DEICE OVTEMP lightsometimes illuminates during HPbleed operation. Since we know it’sonly because of the HP air, can wedisregard the light?”

I t i s poss ib le tha t b leed a i rtemperature upstream of the deicedistributor valves (downstream of thepressure regulator) may exceed 150º C.when high pressure bleed air is present.This is especially likely in event thatairflow over the nacelle bleed air pre-cooler area is limited—such as mayhappen when operating with a featheredpropeller, tailwind, etc., even withbenefit of the pre-cooler jet pumpaction. In any event, illumination of thecaution light cannot be ignored, and theabnormal checklist should beaccomplished. If the DEICE OVTEMPlight extinguishes, the abnormalchecklist allows continued operation—however, use of HP bleed air on theground may be restricted.

“Can I run the RECIRC fans withoutdamage if a ground air conditioningcart is connected and running, even ifaircraft’s ECS is off?”

Yes, as long as ground air cartoperation is monitored, and the RECIRCswitch(es) are selected OFF if ground airshould become unavailable.

A

QA

QAP/FD

“Why doesn’t the autopilotdisconnect with yellow AIL, RUD,or EL alerts like it does on my‘other’ airplane?”

The Saab 340’s autopilot systemwill advise you, via the above-mentioned annunciators, when theaffected servo has reached approx-imately 80% of its capability. In otherwords, letting you know that it’sworking pretty hard. Such forces maybe the result of control surface mis-trim, OEI flight, flap extension/retraction, unusual resistance in controlcircuits (i.e., cables, pulleys, etc.), orsome external factor. Once a servo hasreached the limit of its capability tomaintain commanded attitude, theaircraft will begin deviating from theintended flight path, but autopilot willremain engaged. This most certainlywill not occur without priorillumination of the effected yellowalert. Such system protocol isconsidered much more desirable thanan out-of-trim aircraft triggering asudden autopilot disconnect withoutwarning.

QA

“Stuff you’ve written here conflicts with my company’s policies andprocedures. What should I do?”

Always follow your companies’ approved policies and procedures, but feel freeto discuss the preceding recommendations with your flight ops managementpersonnel, if appropriate.

“Any final words?”

Yes – keep flying safe, and keep flying Saab!

W i n g t i p s M a r c h 2 0 0 38

Wing t ip s

This article is a reminder to startplanning for the implementation ofTAWS in your Saab 340 fleet, if notalready in place.

With time pressing, many Saab 340operators are now starting to line upfor TAWS. The orderbook is growingconstantly as the mandated installationdate approaches, so care needs to be takento minimize aircraft downtime. Bearing inmind the TAWS installation requiresapproximately 200-230 man hours and 7-10 days on ground, it is sensible to planthe installation together with a 4,000 hourcheck or similar. However, the 4,000 hourcheck interval for a Saab 340 indicates thatthere is likely to be only one scheduledbefore 2005 and if that one is missed, the

aircraft will be out of service, on groundfor at least a week just for TAWS. To avoidsuch a situation, it is highly recommendedthat TAWS planning is started now.

With an increasing orderbook, it isbecoming more difficult to managespeedy deliveries. The current, guaranteedlead-time is six months, indicating theimportance of placing a Purchase Order atleast six months ahead of a scheduledinstallation. In some cases a shorter lead-time may be possible, but should not berelied upon.

The following mandates apply:FAA March 29, 2005JAA January 1, 2005CASA July 1, 2005

TAWS updateby Per Skogsberg, Sales Manager, Modifications

Saab Aircraft has recently upgraded its Parts Exchange Program(PEP) and introduced its new Repair and Overhaul Service(REPOS) to provide operators with more flexibility in theirchoice of support package. Each operator’s needs are differentbut one thing remains constant, the need to cost-effectivelykeep aircraft well maintained and in the air earning revenue.Saab’s support options do just that.

For new operators, or those with a smaller fleet, the newlyrestructured PEP provides a tailor-made exchange and repairservice eliminating the need to hold a large stock of spares aswell as the manpower and systems needed to manage thatstock.

In short, PEP acts to keep your capital investment off theshelf and in your operation, where it is most useful. Each pack-age is tailored to the needs of the airline providing local accessto a global pool of spares, cutting turnaround time to a mini-mum. The package also provides access to the latestmodification standards on most repairable parts.

Cost is based on a flight hour/cycle, enabling effective bud-get planning and control. The new PEP price structure offersindividual operators the opportunity to directly affect the costbased on performance. Influencing factors include the initial

investment in spares, removal rate of components, flight hoursand cycles per aircraft and the return and processing of ex-change units.

In a long-term agreement with Group partner, Saab Avio-comp, Saab Aircraft has selected the company as its preferredsupplier of repair and overhaul services for almost all Saab 340components. In conjunction, Saab Aircraft has also recently in-troduced a new support package, known as REPOS, for thoseairlines with a larger Saab 340 fleet and/or an existing mainte-nance infrastructure, where PEP is not appropriate.

REPOS is the solution for those operators who choose tomaintain their own spares pool while enjoying the benefits andefficiencies of a large scale repair and overhaul program. Oper-ators can select which components from their own inventoryare covered for repair and paid for on a predicted flighthour/cycle basis.

Both programs offer enormous benefits to the airline interms of improved planning, budget control and reduced logis-tics. Saab benefits by streamlining its operation and gainingefficiencies that improve its ability to offer flexible, tailor-madeservices to its customers.

Flexible logistic solutions to fit any operation

Saab 2000 TAWSTAWS for the Saab 2000 iscurrently under development, withthe SBs estimated to be releasedby the end of 2003. Moreinformation will follow later.

Please call, e-mail or fax formore information. Also, please visitthe Honeywell web site atwww.egpws.com.

Per SkogsbergSales Manager, ModificationsSales & MarketingPhone +46 13 18 3928Fax: +46 13 18 5115E-mail:per.skogsberg@saabaircraft.com

W i n g t i p s M a r c h 2 0 0 3 9

Wing t ip s

Structural design and maintenance principles

All of us in the aviation communityare fully aware of how importantairframe inspections are in thepursuit of continuing airworthiness.In order to provide a deeperunderstanding of these concerns andthe considerations behind theseinspections, we provide a briefdiscussion of the design programand its history.

There is a term that you may hear fromtime to time, but how many of us fullyunderstand it? The term is DamageTolerance. Essentially, and by definition, itis a process whereby an aircraft is designedto ensure that should serious metal fatigue,corrosion or accidental damage occurwithin the operational life of the aircraft,the remaining structure can withstandreasonable loads without failure, orexcessive deformation until the damage isdetected and repaired.

Designed as a fully Damage TolerantAircraftThe Saab 340 was one of the first aircraftdesigned as a fully Damage TolerantAircraft from the ground up. This processwas known as Maintenance SteeringGroup 3 (MSG-3) and is the third revisionof a process that is still used today. This

process not only controls the airframe butall systems, including the powerplant. Theend result is the Maintenance ReviewBoard Document (MRB), which is thetotal inspection handbook for eachspecific aircraft.

OK, so what does this all mean?Basically the idea is that the design andmaintenance process are completelymatched to each other so that there is aninspection program targeted to look atspecific areas at the right interval and withthe type of inspection adequate to detectdamage of any kind prior to it becoming aserious problem. This allows for repairs tobe accomplished within the scope of theStructural Repair Manual (SRM) orengineering repair statements to beissued by Saab.

This ability to match the inspectionprogram to the airframe alsoenabled engineers to save alot of unnecessary weight inthe design. The end resultensures a well designed andbuilt airframe requiringminimal inspections andallowing for easy saferepairs, while still meetingor exceeding airworthinessrequirements at all times.

Operational life spansFinally, I would like tomention the operationallife of the aircraft. Both the340 and the 2000 haveoperational life spansassigned to them. These aredemonstrated limits on boththe number of flight hoursand landings that may beflown within the parametersof the MRB program. Flightbeyond these limits must be

approved by both the authorities andSaab. For the 340, the the Design CycleGoal (DSG) is 45,000 Flight Hours(60,000 FH extension available) and90,000 landings. For the Saab 2000 it is60,000 FHs and 75,000 Landings. Thepresent DSG encompasses the entireairframe including removal ofcomponents such as flight controls,landing gear components and doors, so itis imperative that these items be tracked.

Both the 340 and the 2000 haveproved to perform extremely well intheir working environments and themaintenance programs to be providing theright mix of useful service withoutextended downtimes. We expect that bothairframes will provide continued safe andefficient service well into the 21st Century.

by George Caracost, Customer Service Director (and former Structure Specialist)

Saab 340 structural test rig Fatigue and life cycle test rig

W i n g t i p s M a r c h 2 0 0 310

Wing t ip s

The Airplane Flight Manual (AFM),published by Saab, forms thebaseline for all takeoff, landing andenroute performance limitationsshould an engine failure occur duringflight. These performance figures areregulated by the airworthinessauthorities and must be achievableby every aircraft in the fleet.

While most of us are aware of theimportance of keeping all aerodynamicsurfaces in a satisfactory condition to maintainflight characteristics and performance, thepropeller blades are all too often neglected.

The propeller airfoil also acts like alifting surface, or wing, producing lift anddrag. Combinations of these forces are“felt” like thrust and torque (see Figure 1right). If an airfoil suffers a disturbance, twothings happen: Firstly, for a given lift, thedrag increases (Figure 2). In the second,(Figure 3), the airfoil produces less lift for acertain angle of attack (i.e. the incidencebetween the airfoil and the flow of air) andthe maximum angle of attack decreases, orstalls at a lower angle of attack.

When setting torque and propeller rpmon a propeller with significant disturbanceson the airfoil, the system will drive thepropeller blade pitch to match both therequired torque and rpm. In a high powersituation, this normally results in thepropeller working with a relatively highangle of attack with the disturbed airfoilgenerating less lift but more drag. (SeeFigures 2 and 3.)

Fortunately, since the workingenvironment of a propeller can be harsh,parameters are normally generous. Forexample, disturbances causing up to 50%more drag for a given lift result in a thrust

degradation of about 1%.Significant steps on theairfoil may also cause parts ofthe propeller airfoil to stall,significantly increasing dragand reducing lift.

Such degradation hasbeen seen to cause thrustreductions of 3% to 5%. Atfirst glance, these thrustreductions seem quitesmall, however with regardsto aircraft performance, thepicture is very different. Theclimb capacity of a heavyaircraft in single engineconditions is fairly modestand the difference betweenavailable thrust and air-frame drag is small. Thetotal thrust, however, is not,hence a 5% loss in thrustmay, in limiting conditions,be nearly 25% of the climbcapacity. Each percentage oflost thrust will adverselyaffect performance cap-ability.

Propellers have beenseen in operation that aremore worn than recom-mended:• Significant erosion behindthe nickel guard on theouter part of the propellerblades. (Figures 4 & 5)• Significant step behind thenickel guard down to thepropeller surface • Loose edges or significantair bubbles on the erosiontape of the propeller de-icing boots. (Figure 6.)

Maintaining aircraft performanceby Joakim Andersson, Manager, Aerodynamics–Operations Engineering

Propellerairfoil

Air flow

Lift

Drag

Thrust

Force feltby torque

Propellerrotationdirection

Aircraft speedvector

Lift

Drag

Clean airfoil Disturbed airfoil

Lift

Angle of attack

Clean airfoil

Disturbed airfoil

Figure 1

Figure 2

Figure 3

W i n g t i p s M a r c h 2 0 0 3 11

Wing t ip s

With the retirement of two long-serving colleagues, SaabAircraft is pleased to announce some new appointmentsto the Management Team in Linköping.

Bjorn Ohlmarks, Vice President, Saab Aircraft and aveteran of the Saab team, is retiring in the middle of 2003and looking forward to some enjoyable days huntin’,shootin’ and fishin’. After joining the Product Supportdepartment in 1981, he became involved in a number ofdifferent activities throughout the division, including ashort spell in the corporate head office. Of particularsatisfaction to him, however, was the time spent onstudies and pre-project planning leading up to the launchof the Saab 2000.

Effective January 1, Michael Andersson takes over asVice President, Saab Aircraft, working in parallel withBjorn Ohlmarks for the six months leading up to hisretirement to ensure a seamless handover.

Michael started his career with Saab some 20 yearsago when he joined as a Flight and Ground Test Engineer.From there he transferred to what was then the ProductSupport organization before widening his experience inthe Avionics Division. In 1994 he moved to GovernmentSales before returning to head up Sales & Marketing inwhat was by then the reorganized Saab Aircraft AB.

Peter Erlingborn takes over from Michael, becomingDirector Sales & Marketing. Previously Sales & MarketingCustomer Service Director, Peter first joined Saab as aTechnical Publications author in 1986, becoming Director,Technical Publications three years later. Prior to joiningSaab, Peter worked with the Swedish CAA, and then SAS,specializing in airfield calibration projects both at homeand abroad.

In the Finance Department, Lena Svensson becomesthe new Finance Director, taking over from Lars Kinellwho also retires this year. Lena, a qualified accountant isa relative newcomer to the Saab team, having joined inMay 2001 from her previous position with a privateaccountancy firm.

The departure in March this year of Lars Kinell marksthe end of a 30-year career with the company that startedat Data Saab.

Managementchanges

• Rough edges on the propeller de-icingboots.

How to avoid the performance losses?In order to keep damages and propellerairfoil disturbances on a level acceptablefrom an aircraft performance point of view,it is important to follow the restrictions andrecommendations outlined in applicablepropeller maintenance instructions. Doingso will ensure any thrust loss will be smallenough to fulfill the performance figuresoutlined in the AFM.

Bjorn Ohlmarks

Michael Andersson

Peter Erlingborn

Lena Svensson

Figure 5

Figure 6

Figure 4

Operator Country 340 2000

Americas

Aerolitoral Mexico 22

American Eagle USA 96

Calm Air Canada 4

Chautauqua USA 4

Chicago Express USA 17

Colgan Air USA 7

Corporate Express Canada 1

Cummins Diesel Aviation USA 1

GMWTS USA 2

Kelly Springfield USA 1

University of Indiana USA 1

Mesaba Airlines USA 80

Peninsula Airways USA 2

Penske Racing USA 1

Provincial Airlines Canada 2

Shuttle America USA 18

TransWest Air Canada 1

Operator Country 340 2000

Europe & Africa

Air Botnia Finland 5

Anglo American South Africa 1

Aurigny Air Services Great Britain 3

Carpat Air Romania 4

SWISS Switzerland 30

Crossair Europe France 3

Golden Air Sweden 11 2

Greek Air Force Greece 2

Grossman Air Service Austria 1

Hellenic Greece 2

Kenya Flamingo Airways Kenya 2

Lithuanian Airlines Lithuania 3

Loganair Great Britain 8

Moldavian Airlines Moldavian Rep 3

Nordic Airlink Sweden 1

Ostfriesische Lufttransport Germany 1 1

Operator Country 340 2000

Europe & Africa

Regional Airlines France 8

Scan Con Airways Denmark 2

Skyways Sweden 11

Swedish Air Force Sweden 5

Swedline Sweden 5

Asia & Australasia

Air Nelson New Zealand 16

Air Rarotonga Cook Islands 1

Cosmic Air Nepal 1

Hokkaido Air System Japan 3

Japan Air Commuter Japan 11

Japan Civil Aviation Bureau Japan 2

Japan Coast Guard Japan 2

Macair Australia 2

Regional Express Australia 21

Shandong Airlines China 4

Saab ope ra to r s