turn analysis

FLIGHTOPERATIONS

ENGINEERING

1For Training Purposes Only © Copyright 2009 Boeing

Turn Analysis

Magaly CruzFlight Operations Engineering

Boeing Commercial AirplanesMarch 2009


Contents

• Why Consider a Turn Analysis• Regulatory Requirements• Obstacle Information Sources• Turn Analysis Performance Methods (Sample Problem)

• Examples of Special Airport Studies• Engine Inoperative Turn Calculation Updates


Why Consider A Turn

• Airport departure procedures for obstruction clearance assume that aircraft are capable of maintaining a climb profile which is normally achievable with all engine climb performance. Continued adherence to departure procedures may not be possible in the event of an engine failure

• Contingency procedures may be required to provide for any situation occurring during the departure procedure in which the aircraft becomes unable to maintain specified climb gradient . . .

(Paraphrased from ICAO procedures for air navigation services -aircraft operations, volume II - construction of visual and instrument flight procedures)


Performance Consequences

In many cases a turn will eliminate the need to consider limiting obstacles.

• Increases maximum takeoff weight− Improves payload and/or range

• May introduce new obstacles into the flight path

• Range of allowable V2 speeds limited to maintain desired turn radius− May result in a minimum and/or maximum allowable takeoff

weight

• Need to check margin to stick shaker for banks in excess of 15°

• Airplane performance change: Gradient loss, effect of wind


Contents

• Why Consider a Turn Analysis

• Regulatory Requirements

• Obstacle Information Sources

• Turn Analysis Performance Methods (Sample Problem)

• Examples of Special Airport Studies

“FAA Corridor” “ICAO Splay”


FAR 121.189

d) No person operating a turbine engine power transport category airplane may take off that airplane at a weight greater than that specified in the Airplane Flight Manual –2) ...that allows a net takeoff flight path that clears all

obstacles either by a height of at least 35 feet vertically, or by at least 200 feet horizontally within the airport boundaries and by at least 300 feet horizontally after passing the boundaries.

f) For purposes of this section, it is assumed that the airplane isnot banked before reaching a height of 50 feet, as shown by the ... net takeoff flight path data ... in the Airplane Flight Manual, and thereafter that the maximum bank is not more than 15 degrees.


ICAO Annex 6 - Operations Of Aircraft

3.1 No aeroplane is taken off at a weight in excess of that shown in the Airplane Flight Manual to correspond with a net takeoff flight path which clears all obstacles either by at least a height of 10.7 m (35 ft) vertically or at least 90 m [~300 ft] plus 0.125 D laterally, where D is the horizontal distance the aeroplane has traveled from the end of takeoff distance available ... It is assumed that the aeroplane is not banked before the clearance of the net takeoff flight path above obstacles is at least 15.2 m (50 ft) and that the bank thereafter does not exceed 15 degrees.

3. Takeoff obstacle clearance limitations


Vertical Obstacle Clearance

FAA / ICAO / EU-OPS

FAA/ICAO: Turn allowed when 50 ft height reached 15° max bank, unless exemption is granted

EU-OPS: see following slide

Gross Flight Path

Net Flight Path 35 ft

* For EU-OPS, 50 ft clearance required for banks greater than 15°

*


Max Bank Angle – EU-OPS

Track changes shall not be allowed up to the point at which the net take-off flight path has achieved a height equal to one half the wingspan but not less than 50 ft above the elevation of the end of the take-off run available. Thereafter, up to a height of 400 ft it is assumed that the aeroplane is banked by no more than 15°. Above 400 ft height bank angles greater than 15°, but not more than 25°may be scheduled;

(c) (1)

An operator must use special procedures, subject to the approval of the Authority, to apply increased bank angles of not more than 20° between 200 ft and 400 ft, or not more than 30° above 400 ft.

(3)

EU-OPS 1.495 (Formerly JAROPS 1.495)


Horizontal Obstacle Clearance

FAA AC 120-91 “Airport Obstacle Analysis” provides additional guidance material regarding obstacle clearance. Outlines two methods “area analysis” and “flight track analysis”.

200 ft (61 m)

Airport Boundary

300 ft (91 m)

FAA Corridor


Horizontal Obstacle Clearance

VMC by Day < 15 Degrees 300 mVMC by Day > 15 Degrees 600 mIMC/VMC Night < 15 Degrees 600 mIMC/VMC Night > 15 Degrees 900 m

90 m

Condition Heading Change Max Half Width

900 m 600 m 300 m

4080 m 6480 m

1680 m

* For EU-OPS, 90m or 60m + ½ wingspan is allowed, whichever is less

*

ICAO / EU-OPS SplayICAO Annex 6: 3.1.1 - 3.1.3; EU-OPS 1.495 (d) - (e)


Boeing Heritage Wingspans

• 717-200: 93 ft (28m)• 737-100/200: 93 ft (28m)• 737-300/400/500: 95 ft (29m)• 727-100/200: 108 ft (33m)• 737-600/700/800/900: 113 ft (34m)• 757-200/300: 125 ft (38m)• 767-200/300: 156 ft (48m)• 767-400: 170 ft (52m)• 747-100/200/300: 196 ft (60m)• 777-200/300: 200 ft (61m)• 777-300ER: 213 ft (65m)• 747-400: 213 ft (65m)

Smaller EU-OPS initial splay half-width allowed:(½ span + 60m)

Greater EU-OPS vertical distance to start of turn:

(½ span)


McDonnell Douglas Heritage Wingspans

• DC-9: 89-93 ft (27-28m)

• MD-80/90: 108 ft (33m)

• DC-8: 142-148 ft (43-45m)

• DC-10-10: 155 ft (47m)

• DC-10-30/40: 165 ft (50m)

• MD-11: 170 ft (52m)

Smaller EU-OPS initial splay half-width allowed for all Douglas heritage airplanes (½ span + 60m)

Greater EU-OPS vertical distance to start of turn:

(½ span)


Obstacle Accountability Area Summary

N/A

300 ft

200 ft

35 ft

FAA

12.5%12.5%6.25%, or 12.5%(3)Splay %

~1000 -3000 ft~1000 -3000 ft2000 ft or 3000 ft(2)Final Splay Half-Width

295 ft(5)295 ft200 ftInitial Splay Half-Width

35 ft(4)35 ft35 ft(1)Vertical Clearance

EU-OPSICAOFAA AC 120-91

(1) Clearance calculated from lowest part of airplane for banks > 15°(2) 3000 ft for turns with heading changes > 15°(3) 12.5% (when the turn begins) for turns with heading changes > 15°(4) 50 ft for banks > 15°(5) 197 ft plus ½ wingspan allowed


Contents

• Why Consider a Turn Analysis• Regulatory Requirements• Obstacle Information Sources• Turn Analysis Performance Methods (Sample Problem)

• Examples of Special Airport Studies• Engine Inoperative Turn Calculation Updates


Airport/Obstacle Information

• Airport Characteristics Data Bank (ACDB)– Volume 1 Summary and Explanation– Volume 2 Africa - Indian Ocean Region– Volume 3 Caribbean and South American Regions– Volume 4 European Region– Volume 5 Middle East and Asia Regions– Volume 6 North Atlantic, North American and

Pacific Regions

• Aerodrome Obstruction Chart - Type A

http://www.icao.int http://icaodsu.openface.ca

ICAO Sources



NAT

AFI ASIA

NAM

PAC SAM

CAR MID

PAC

EUR

ICAO Air Navigation Regions


Airport Characteristics Data Bank


ICAO Type A Aerodrome Obstruction ChartInnsbruck, Austria



• Published by most national governments

• Provide Standard Instrument Departure (SID) procedures

− Minimum performance requirements

− Climb profile (minimum gradient)

− Maneuvering limitations (maximum turn radius)

Aeronautical Information Publications (AIP)


AIP Standard Instrument DepartureInnsbruck Rwy 08/26

(Example of required minimum climb profile)


Visual Approach Chart (IFR) For All Aircraft



• Airport and Obstacle Database (AODB)

– Provides data in digital and graphical formats for nearly 3000 airports

– Available with monthly or yearly subscription fee

– Online data download available with daily revisions

http://www.aodb.iata.org

IATA



• Airport Data Service

– Part of Jeppesen’s OpsData programs and services

– Runway and obstacle data for airports worldwide

Email: [email protected]: http://www.jeppesen.com

• Airway Manuals

– Limited obstacle information in graphical form

Jeppesen



• National Aeronautical Charting Office (NACO) ~ part of the FAA Aviation Systems Standards - http://www.naco.faa.gov

• Airport Obstruction Charts (AOC)– Created from data provided by NOAA National Geodetic

Survey (NGS) - http://www.ngs.noaa.gov– Includes tabular data: Aeronautical Data Sheets (ADS)

• Digital Aeronautical Information CD (DAICD)– Digital Aeronautical Chart Supplement

• High/Low Altitude Airways• SIDS, STARS, and Departure Procedures

– Digital Obstacle File (DOF)– NAVAID Digital Data File

United States Airports



• Geological Survey Maps– Maintained by Department of the Interior Geological Survey– Provide surface contour information and some obstacles

• Airport Inspection Forms 5110– Provided by airport authorities for virtually all U.S. Airports– Compiled for each state by FAA Regional Offices

• AirNav (http://www.airnav.com)– Airport runway information– Limited obstruction data– NAVAIDs and Instrument Procedures

United States Airports (cont’d)



• SITA

• LIDO

• Topographical Maps

• Airport Authority

• Google Earth

• Others?

Other Sources


Obstacle Data Requirements

7. Sources of Obstacle Data. Operators are expected to use the best and most accurate available obstacle data for a particular airport at the time of analysis. Data sources do not require specific FAA approval. Operators should be aware that . . . any single source may not include all the pertinent information necessary for doing a takeoff analysis.

FAA AC 120-91

FAA Order 8400.10 “Air Transportation Operations Inspector’s Handbook” [Volume 4, Chapter 3, Section 4] contains guidance information for POI’s to approve airport data acquisition systems.


Contents

• Why Consider a Turn Analysis• Regulatory Requirements• Obstacle Information Sources• Turn Analysis Performance Methods

(Sample Problem)• Examples of Special Airport Studies• Engine Inoperative Turn Calculation Updates


Turn Analysis Procedure

• Study the terrain in the area around the airport and select a departure path– Several paths may have to be analyzed

• Determine any critical obstacles for the chosen departure path

• Determine the required turn radius

• Examine other issues:– Weather (winds, OAT, QNH)– Piloting considerations


Example Problem

Allowable takeoff weights based on a 15 degree climbing banked left turn [2266m maximum radius] commenced 4080m from the end of the runway to magnetic heading 270 degrees.

This procedure is based on a VFR departure only.

Takeoff Procedure


Example Problem

Obstacle 2 - 320m

4080m

Radius - 2266m

2800m

Conditions: VMC by Day,ICAO Guidelines

Large O

bstacles

Obstacle 1 - 160m

600m


Performance Considerations

• Performance limited weight consideration– Field Length– Climb– Obstacle– Tire Speed– Brake Energy

• In addition– Weight associated with turn radius limited

speed


Effect Of Speed On Turn Radius

Centripetal acceleration: a = V 2 / R

FasterSpeed

SlowerSpeed

R = V 2 / aR = V 2 / [g*tan(φ)]


Turn Radius Limited Speed

Given: Turn radius = 2266m; Bank angle (φ) = 15°

Find turn radius limited speed: VT = R*g*tan(φ) [g = 9.81 m/s2] VT = 2266m*9.81 m/s2*tan(15°) VT = 77.2 m/s Conversion Factor = 1.944 [knots / (m/s)] VT = 150 KTAS



Alternatively:

From the PEM find the turn radius limited true airspeed by entering bank and turn radiusof 7500 ft (2266m)

14

13

12

11

10

9

8

7

6

5

4

3

2

1

050 1510 2520 3530 4540 50

True Airspeed (knots)

1.5° per second turn(4 min. turn)

Radius of turn (1000 ft)

Angle of bank, degrees

2001901801701601501401301203° per second turn(2 min. turn)


Convert from true airspeed to indicated airspeed:

V2MAX = VT * σ σ = = = 0.878

V2MAX = 150 * 0.878

V2MAX = 141 KIAS


Weight associated with V2MAX is the Turn Radius Limited Weight

δ 0.8961.02 θ

Given: Turn radius = 2266m; Bank angle (φ) = 15° Airport Pressure Altitude = 915m (δ = 0.896)

OAT = 20°C (θ = 1.02)


Calculation Methods

• AFM-DPI Airplanes (777, 737ng, 747-400, 757-300, 767-400ER)– Use BTM “first principles” databases which can

calculate turning departure performance directly

• Non-AFM-DPI Airplanes– Use BTOPS “model table” lookup which only considers

straight-out departures– Must artificially adjust obstacle heights and locations– Need to calculate the “equivalent still air distance” for

analyses with wind


Distance To Obstacles

Equations:

arc1 = (50°/180°)*π*Rarc2 = (130°/180°)*π*R

Obstacle 1 - 160m

arc1

50°

arc2

Obstacle 2 - 320m

4080m

2800m

Non AFM-DPI Airplanes


2800 m

Distance to obstacle 1: D1 = 4080m + (50/180)π*2266mD1 = 4080m + 1980m

D1 = 6060m

Distance to obstacle 2: D2 = 4080m + π*2266m + 2800mD2 = 4080m + 7120m + 2800m

D2 = 14,000m

Obstacle 2

4080 m 50°

Obstacle 1

Distance To ObstaclesNon AFM-DPI Airplanes (continued)


Adjust Obstacle Height

Why do we adjust height of obstacle?• Boeing takeoff performance software for BTOPS airplanes

considers only straight out departures.• Climb capability in a turn is decreased• Adjusting height will yield an equivalent straight out

departure

Equations related to climb gradient:

295.4σ SV2

Wcos(φ)

( ) W1 + ƒacc

T-D∆DW

CL = γ = ∆γ ≈ ∆CD

CLφ=0

≈

Non AFM-DPI Airplanes (continued)


.5


• From the Boeing Performance Engineering Manual:

0 5 10 15 20 25Bank angle, φ (degrees)

0

1.0

1.5

2.0

• Low speed• Gear up 15, 25

Gradient decrement (%)

Flaps

1

UP

5, 10




Gradient decrement = 0.6% or 0.006

Obstacle #1:

Obstacle #2:

12m

0.006

0.006

43m

Adjusted obstacle height:160m + 12m = 172m

Adjusted obstacle height:320m + 43m = 363m

1980m

7120m



Actual Takeoff Flight Path

Start of turn

End ofturn

43m

320m 12m 160m

7120m

14,000m

4080m 1980m

Actual takeoff flight path considering turnEquivalent straight out departure



Sample Problem

Non DPI Airplanes

AFM-DPI Airplanes

Cert Type

363014000#2

17206060#1

320-45321280#2

160-14575815#1

Height (m)Lateral Distance (m)

Longitudinal Distance (m)Obstacle

Obstacle Definition Summary

equivalent straight out departure


Boeing Calculation Tools

• Certified Performance– Paper AFM– AFM-DPI

• Takeoff Analysis– Boeing Performance Software (BPS)– Standard Takeoff Analysis Software (STAS)

• Analytical Tools– Performance Engineers Manual (PEM)– Boeing Climbout Program (BCOP)


Sample Problem InputBoeing Performance Software (BPS)

• BPS is a graphical user interface for many individual Boeing software programs:

– STAS (Takeoff)– LAND (Landing)– INFLT/REPORT (Enroute)– APM/HISTRY (Cruise

Performance Monitoring)

• Turn analyses may also be calculated using STAS directly


Sample Problem InputBPS Obstacle Splay Setup

AFM-DPI airplane certifications only

• ICAO/JAA splay definition for VMC by day and heading change greater than 15°

• Non AFM-DPI airplanes incapable of excluding obstacles outside a splay


Sample Problem Input

Rwy 09a:Definition for actual obstacle locations

(turn calculated directly by BPS)

Rwy 09b:Definition for “equivalent straight out departure”(representative of BTOPS airplane definition)

BPS Obstacle/Turn Definitions


Sample Problem Results

ELEVATION 915 M XYZ

*** FLAPS 05 *** AIR COND AUTO ANTI-ICE OFF NO NAME NOWHERE, USA

737-700 CFM56-7B22 DATED 23-MARCH-2004MAX BRAKE RELEASE WT-KG, LIMIT CODE AND TAKEOFF SPEEDS FOR ZERO WINDTAKEOFF OAT CLIMB ** RWY 09a ** ** RWY 09b **PWR DEG C LIMIT WEIGHT V1 VR V2 WEIGHT V1 VR V2

94.0 30 62000 55300* 122 124 129 55100* 122 124 12994.4 28 63100 56400* 123 125 130 56100* 123 125 13094.7 26 64300 57500* 124 126 132 57200* 124 126 13294.9 24 65500 58500* 125 128 133 58300* 125 127 13394.6 22 65500 58600* 126 128 133 58300* 125 127 13394.3 20 65600 58600* 126 128 133 58300* 125 127 13394.0 18 65600 58600* 126 128 133 58400* 125 127 13393.7 16 65700 58600* 126 128 133 58400* 125 127 13393.4 14 65700 58700* 126 128 133 58400* 125 127 13393.1 12 65800 58700* 126 128 133 58400* 125 127 13392.8 10 65800 58700* 126 128 133 58400* 125 127 13392.5 8 65800 58700* 126 128 133 58400* 125 127 13392.1 6 65900 58700* 126 128 133 58400* 125 127 13391.8 4 65900 58700* 126 128 133 58400* 125 127 13391.5 2 66000 58800* 126 128 133 58500* 125 127 13391.2 0 66000 59200* 127 128 134 58500* 125 127 133

MAX BRAKE RELEASE WT MUST NOT EXCEED MAX CERT TAKEOFF WT OF 68945 KGLIMIT CODE IS F=FIELD, T=TIRE SPEED, B=BRAKE ENERGY, V=VMCG, *=OBSTACLE/LEVEL-OFF

OBS FROM LO-M/M RUNWAY HT DIST OFFSET HT DIST OFFSET HT DIST OFFSET09R 160 5815 -1457 320 1280 -453209L 172 6060 0 363 14000 0

Turn calculated by BPS

Equivalent straight-out departure

Results demonstrate general equivalence between the two methods


Wind Effects

• AFM-DPI Airplanes (777, 737ng, 747-400, 757-300, 767-400ER)– BPS and AFM-DPI are capable of handling the

changing wind component

• Non-AFM-DPI Airplanes– Need to set up an equivalent still air straight out

flight path– The effects are non-linear – potential for

headwind, crosswind, and tailwind– Equivalent obstacle distances and heights will be

different


Flight Path With Wind

Crossw

ind

20 Knotwind(10.3 m/s)

No wind path Wind path

Tailwind

Headwind

Obs 2

Obs 1

For Training Purposes Only © Copyright 2009 Boeing

Flight Path With Wind (continued)

∆X=Wind speed*Time∆X=10.3m/s * [45°/2 deg/s]∆X=237m

Flight path displaced:

Time Displacement

45°

∆X

23s 237m

Rate of heading change (ψ):ψ = Total Heading Change / Total Timeψ = 180° / [7120m / 77.2 m/s]ψ = 2 deg/sec


Flight Path With Wind (continued)

475m

23s 237m46s 475m69s 712m92s 950m

Flight path displaced:

Time Displacement

237m

712m

950m


∆X=Wind speed*Time


Adjust Obstacle Distance and Height

Develop the Equivalent Still Air Distance formula

Non AFM-DPI Airplanes

Dair = * DgroundVair

Vground


Vair - headwind

Two key relationships:Dground = Vground * TimeDair = Vair * Time Time is the same

Rearrange these expressions:

Recognize that Vground = Vair - headwind:



Find equivalent still air distances:


d1

d4d3

d2

d1air = * 4080m 77.2m/s77.2m/s – 10.3m/s

d1air = 4710m


As an example, find d1air:


Vair - headwind Obs 2

Obs 1



Find equivalent still air distances:


d1

d4d3

d2

d1air = 4710md2air = 2430md3air = 4755md4air = 1630m



Vair - headwind

Dair Obs1 = d1air + d2airDair Obs1 = 7140m

Dair Obs2 = d1air + d2air + d3air + d4airDair Obs2 = 13525m

Requires integration due to changing wind component

Obs 2

Obs 1



Find adjusted heights:


d1

d4d3

d2


Hadjusted = Hactual + Grad. Decrement * Dist

HObs1 = 160m + 0.006*2430mHObs1 = 175m

HObs2 = 320m + 0.006*(2430m+4755m)HObs2 = 363m

Obs 2

Obs 1

d3aird2air


Obstacle Definition Summary

36301352520 kt

1750714020 kt

#2

#1

Obstacle

363014475-10 kt

3630140000 kt

17105610-10 kt

172060600 kt

Height (m)Lateral Distance (m)

Longitudinal Distance (m)Wind

Wind Effect – Non AFM-DPI Airplanes

equivalent straight out departure


Calculation Tools: AFM-DPIIntroduction

• Source of certified performance data for 777, 737ng, 747-400, 757-300, and 767-400ER

• Also available as a retrofit on models formerly certified with paper AFM performance, including 747-400, 767-200 and 767-300

• First principles calculation optimizes takeoff, landing, and enroute limit weights


Calculation Tools: AFM-DPI (cont’d)Defining Turns

selecting a turning departure

defining the turn


Calculation Tools: AFM-DPI (cont’d)Result Excerpts

Point Calculation

All Limit Weights Trend Data ----------------------------

Certificate Limit: Maximum Takeoff Weight = 81646 KG Minimum Takeoff Weight at Brake Release = 40824 KG

Wind Field Obstacle(Both) Length Climb ClearanceKnots KG KG KG------- --------- --------- ----------10.00 58083+ 65587 58083+ 0.00 62514 65587 58627+ 10.00 64055 65587 58633+ 20.00 65650 65587 58667+ 30.00 67303 65587 58678+ 40.00 68853 65587 58874+

Obstacles ---------

Obstacle Reference Point: Liftoff End of Runway Obstacle clearance (Clrnc.) includes required regulatory margin.

Dist. Ht. Offset Clrnc. | Dist. Ht. Offset Clrnc. # METERS FEET METERS FEET | # METERS FEET METERS FEET -- ------ ------ ------ ------ | -- ------ ------ ------ ------1 5815 525 -1457 81 | 2 1280 1050 -4532 0

Takeoff Limit Weights ---------------------

Field Length Limit 62514 KG #Brake Energy Limit 81647 KG #Tire Speed Limit 81647 KG Climb Limit 65587 KG

CRITICAL: Obstacle Clearance Limit 58627 KG Certificate Limit 81646 KG

Trend Analysis

(no wind)

(trend on wind)

∆ ≈ 800 kg


Calculation Tools: BCOPBoeing Climbout Program (BCOP)

Key Attributes:• All engine and engine out

takeoff, landing, and terminal area performance calculation

• SID/STAR analysis• Approach/Go-Around analysis• FAA Integrated Noise Module

(INM)• Does not solve for gross weight,

does not perform obstacle analysis, or output net flight path data


Calculation Tools: BCOP (cont’d)Introduction

Computation Type

Airplane Config

Airport Info

Navigation

Initial Conditions

In-Flight Starting Conditions


Calculation Tools: BCOP (cont’d)Vertical Profile Example

5

4

3

2

- Denotes end of segment point

1

End at 1000 ft above runway

End at Gear Up V2 + increment

End at flaps up position

End at 250 KIAS

End at 10000 ft above runway

1. Takeoff2. Constant Speed3. Acceleration4. Acceleration5. Constant Speed

Profile Segments


Calculation Tools: BCOP (cont’d)Horizontal Profile Example

2

NAV1

NAV2

NAV3

3

1

Runway DME Distance

Rad

ial X

YZ

1. Fly Heading. Turn to new heading at DME from NAV1.2. Fly Heading. At altitude, turn direct to NAV2.3. Fly Direct to NAV2. Turn to intercept NAV3 Radial XYZ.

Profile Segments


Calculation Tools: BCOP (cont’d)Results From Sample Problem

Height X Pos Y Pos KIAS KTAS ROC Bank Flt Path CL................................... start of turn ...................................285 6100 0 133.2 144.2 423 -15 14.2 1.65112287 6174 2 133.2 144.2 423 -15 14.2 1.65110290 6248 7 133.2 144.2 423 -15 14.2 1.65108292 6322 14 133.2 144.2 423 -15 14.2 1.65105294 6396 24 133.2 144.2 423 -15 14.2 1.65103296 6469 36 133.2 144.2 422 -15 14.2 1.65101298 6541 51 133.2 144.3 422 -15 14.2 1.65099300 6613 69 133.2 144.3 422 -15 14.2 1.65097302 6685 89 133.2 144.3 422 -15 14.2 1.65095305 6755 112 133.2 144.3 422 -15 14.2 1.65092307 6825 137 133.2 144.3 421 -15 14.2 1.65090309 6894 165 133.2 144.3 421 -15 14.2 1.65088

Tabular

Graphical


Calculation Tool for the future:Performance Engineers Tool (PET)

PET Mission Statement:“Flight Operations Engineers’ single point of access for

Boeing airplane performance.”

PET is a graphical user interface that will replaceBPS, BCOP and the AFM-DPI interface for the 787 and all

other DPI airplane models.


Calculation Tool for the future:Performance Engineers Tool (PET) (cont.)

OperationalPerformance

Flight Path selection replaces BCOP

Takeoff selection

Perform Turn Analysis using one single tool


Calculation Tool for the future:Performance Engineers Tool (PET) (cont.)

Certified Performance(AFM-DPI) tab replaces the AFM-DPI interface


Contents

• Why Consider a Turn Analysis• Regulatory Requirements• Obstacle Information Sources• Turn Analysis Performance Methods (Sample

Problem)• Examples of Special Airport Studies• Engine Inoperative Turn Calculation Updates


St. Maarten – Dutch Antilles

Runway 09“Right hand turn MANDATORY. Hazard beacons on hills to the East must be visible.”

Princess Juliana International


St. Maarten Study

(121m) (220m)

84m

757-200 / RB211-535E4 SID Procedure Revised Procedure

Revised Procedure:Climbing banked right turn of radius 1620m for heading change of 97°


St. Maarten Study

Analysis of procedure

Small turn radius required to avoid large obstacles outside of turn

V2 may be very limited due to tighter turn radius• Need to consider bank angle greater than 15°• Analyze each flap setting to find optimum flap

Need to alert flight crew about Billy Folly Hill (121m) inside of turn when operating at less than limited weight


St. Maarten Study

Given turn radius, find limited speed: VT = R*g*tan(φ) R = 1620m

15 127 124

20 148 144

25 167 163

30 187 182

KIAS at sea level and 30°CObs distance = 1620m*π*(97°/180°)+600m = 3340mObs height (actual) = 84m

Bank angle KTAS KIAS


1 0.46 97

5 0.50 98

15 0.63 102

20 0.60 101

Flap Gradient Adjusted obstacledecrement (0/0) height (m)

St. Maarten Study

Takeoff analysis results:MTOW = 78,800 kg Flaps 20 (Optimum Flap), A/C OffV2 = V2Max = 124 KIASTurn radius limited

15° Bank Angle

Limited Weight


1 0.84 107

5 0.93 110

15 1.17 116

20 1.10 114

St. Maarten Study

20° Bank Angle

Limited Weight (continued)

Flap Gradient Adjusted obstacledecrement (0/0) height (m)

Takeoff analysis results:MTOW = 100,000 kg Flaps 20 (Optimum Flap), A/C OffV2 = 140 KIAS; V2Max = 144 KIASObstacle limited


St. Maarten Study

• Certified performance data is targeted to ensure 30° bank angle before stick shaker at V2 (15° banking capability plus 15° overshoot protection)

• When exceeding 15° bank angle, it is advisable to check that adequate overshoot protection of 15° is maintained

• Note: Some Boeing airplanes have more than 30° margin to stick shaker at normal V2 because speeds were increased to satisfy:– Tail strike avoidance requirements, and/or– Minimum unstick speed criteria (Vmu)

Margin to Stick Shaker


St. Maarten Study

Forward CG Wings level190

150000 170000 190000 210000 230000 250000 270000

170

150

130

110

90

UP/UP

Flap/Gear

1/UP5/UP15/UP

25/DOWN30/DOWN

20/UP

Gross weight (lb)

Stick shaker speed, VSS(KEAS)

Margin to Stick Shaker (continued)

From the PEM:Vss = 125 KEAS

757-200 / 535E4 PEM

Important Note:The PEM shows simplified stick shaker speeds. The actual stick shaker speed schedule may additionally be a function of other variables, such as thrust and load factor. Consult with Boeing prior to using this data for your margin to stick shaker assessment.


St. Maarten Study

General equation for bank capability to stick shaker:

Margin to Stick Shaker (continued)

This can be derived by equating the following lift coefficients:

• Actual speed, banked at stick shaker limit• Stick shaker speed, wings level

⎟⎟⎠

⎞⎜⎜⎝

⎛⎟⎟⎠

⎞⎜⎜⎝

⎛°

=⎟⎟⎠

⎞⎜⎜⎝

⎛⎟⎟⎠

⎞⎜⎜⎝

⎛=

SVW

SVWc

ssssLss 22

2)0cos(

2)cos( ρρφ

2

)cos( ⎟⎠⎞

⎜⎝⎛=

VVss

ssφ

Conclusion: Allows 20° bank capability and 17° of overshoot protection. Maneuver margin is still maintained.

In our St. Maarten example, Vss = 125 KEAS and V2 = 140 KEAS:

2

140125)cos( ⎟

⎠⎞

⎜⎝⎛=ssφ °= 1.37ssφ


Effect Of Speed Increase

Speed increase in combination with increased bank angle (beyond 15°) can improve turn capability while maintaining maneuver margin.

Two methods to increase speed:

• Improved Climb– AFM Improved Climb performance data

(used at Innsbruck)• In-air acceleration

– PEM acceleration and climb trades (used at Lhasa)


Improved Climb

0Speed increase (units)

Takeoff safety speed, V2(KIAS)

2 4 6 8 10 12100

110

120

130

140

150

160

170

180

190

200

210V2

• Can specify units of speed increase for turn procedure

• Data can be calculated by AFM-DPI or BPS

• Also published in AFM Section 4 and the Flight Planning and Performance Manual (FPPM)


In-Air Acceleration

From PEM acceleration and climb trade chart

Given 2.5% gradient available, desire V2+15, for V2 = 150kt:

Time (T) in level flightT = 15 kt ÷ AccelerationT = 15 kt ÷ 0.5 kt/s

T = 30 s Distance (D) in level flight

D = Average Speed * TD = 142.5 kt * 30/3600 hr

D = 1.19 nm

-6

Gradient desired (%)

14

-4 -2 0 2 4 6 8 10

12

10

8

6

4

2

0

-2

-4

-6

Tota

l clim

b gr

adie

nt a

vaila

ble

(%)

Acceleratio

n (KTAS/se

cond)

3.5

-2.5

3.0

-2.0

2.5

-1.5

2.0

1.5

-1.0-0.5

1.0

0

0.5


Recommended Speed Increases

In the absence of data from the manufacturer or a more detailed analysis, the following guidance information is available for consideration to help ensure adequate stall margins:

V2+15V2+15V2+15

V2 to V2+15

Boeing FCTM(737,757,767,777)

Speed

–V2+10V2+10

V2 to V2+10

Boeing FCTM(747-400)

V2+10V2+XX25°––30°

V2+5V2+XX/220°V2V215°

AMC OPS1.495(c)(4)

FAA AC120-91

Bank Angle

“Where ‘XX’ is the all-engine operating speed increment (usually 10 or 15 knots)”

Per FAA AC 120-91:NOTE: On some airplanes, the AFM standard V-speeds may already provide

sufficient stall margin protection without additional adjustments.


737-700 / 22KFlaps 5Airport Conditions:

1900 ft, 20°CIn-Flight Conditions:

5000 MSL, 14°C

737-700 / 22KFlaps 5Airport Conditions:

1900 ft, 20°CIn-Flight Conditions:

5000 MSL, 14°C

Example of Speed Increase

TURN RADIUS (METERS)

1592166517381810188319582034211021862262233924142483255226212689275428212899

V2 with15° Bank

1172122612791333138614411497155316091665172217771828187919301980202720772134

V2 with20° Bank

1277133213881444149915571615167317311789184819051958201020632114216422152274

V2+5 with 20° Bank

1081112711721217126213091356140314501497154415901633167517171759179918401888

V2+10 with 25° Bank

9451154400098311846000102112048000105912350000109612552000113512754000117513056000121413258000125313560000129213762000133213964000137014266000140614468000144114670000147714872000151114974000154415176000157915378000161815580000

V2+15 with 30° Bank

V2 (KIAS)

Weight (kg)

Turn Radius Capability Trade at InnsbruckManeuvering within the valley limited to 1700m

15°17°16°11°16°Margin to stick shaker:45°42°36°31°31°Bank to stick shaker (φss):

80000+ kg71000 kg59000 kg63000 kg47000 kgTurn Radius Limited Tkof Wt:


Lhasa

6 At speed Vref 30 +80

• Select FLCH• Set CONT Thrust• Select Eng Out V-NAV Climb

5 At completion of turn

• F/D on• Set speed bug to Vref 30 +80

4 Crossing road

• Speed V2 + 15• 30º bank turn• Continue turn direct RW NDB

NOTE: May get GPWS warning

3

At 200 ft AGL• F/D off• Visually follow road• Set speed bug to V2 + 15• Accelerate to V2 + 15

2 At V2 or engine failure speed

1 Engine failureat or after V1

RW NDG200 mhz 7

Climb to engine outcruise altitude forreturn to Chengdu

Runway 27 Engine Failure Procedure


Contents

• Why Consider a Turn Analysis• Regulatory Requirements• Obstacle Information Sources• Turn Analysis Performance Methods (Sample

Problem)• Examples of Special Airport Studies• Engine Inoperative Turn Calculation Updates


At present our turning flight calculation assumes

• Coordinated turn, i.e., no side force

• Simple relationship between turn radius and bank angle

These assumptions are not consistent with the actual airplane performance and behavior in a turn.

Engine Inoperative Turn Calculation Updates


Coordinated Not Coordinated

β ≠ 0

β = 0

β ≠ 0

“skid”

“slip”


• Airplane cannot accomplish a coordinated turn with one engine inoperative

• FCTM recommends to trim for zero wheel, to achieve near minimum drag (for best gradient)

• To remain on the intended ground track, additional bank angle may be required, possibly reducing the climb gradient capability

• During a fixed bank angle maneuver, the ground track can deviate by a substantial amount



Engine Inoperative Trim Technique

•It is not possible to trim for zero sideslip on takeoff, missed approach, or go-around, at high thrust settings, with one engine failed

•Pilots are trained to trim for zero wheel, to achieve near minimum drag, for best gradient


β ≠ 0 β ≠ 0

Turns into the failed engine

Turns away fromthe failed engine

Example: right engine has failed, airplane turning left:

Example: left engine has failed, airplane turning left:

V2Actual R exceeds g*tan(Φ)

V2Actual R is less than g*tan(Φ)


Drawing for illustration

purposes only

Cross Track

Lateral Flight Path – Constant 15° Bank Angle TurnLa

tera

l Flig

ht P

ath

Left Engine Out

Right TurnLeft Turn


AFM AFM

Airplane

Airplane



Vertical Flight Path – Effect of additional bank angle

• Additional bank angle to maintain track reduces the vertical profile

• AFM net obstacle profile is not violated

Distance from Start of Turn

Hei

ght f

rom

Sta

rt o

f Tur

n

Current AFM (15° bank)

Gross Flight Path

Net Flight Path

Drawing for illustration

purposes only

Actual profile at 18° bank required to hold track


• V2/g*tan(Φ) may not accurately model turn radius with an engine failed:– With constant bank angle:

• Turns toward the failed engine will turn inside the classical radius

• Turns away from the failed engine will exceed the classical radius

– For constant radius turns:

• Turns toward the failed engine will require less bank

• Turns away from the failed engine will require more bank

Engine Inoperative

Turn Radius Summary


Turn Radius SummaryEngine Inoperative

• The engine inoperative turn radius effect just described has not traditionally been included in turn radius calculations for Seattle models; simplified turn equation used for AFM

• Some Douglas models have included it by using different methodology that accounts for engine inoperative performance (717, DC-10, MD-10, MD-11 & MD-90)

• Boeing intends to update AFM-DPI, BTM and the Boeing Climbout Program (BCOP) software to improve the accuracy of engine out lateral track calculations, for all in-production models.

turn analysis

Documents

airplane flight manual

net takeoff flight path

net takeoff flight path

maximum takeoff weight

airplane performance

airplane isnot

engine climb performance

icao procedures