Aircraft stability on the ground - caac.gov.cnAircraft stability on the ground ... On A320 avoiding loading & offloading passengers through the ... Climb and cruise. · 2016-2-3

Aircraft stability on the groundand aircraft centre of gravity limits

April 2013

Presented bySteve BARKER / Senior Performance Engineer

Regional Seminar

Aircraft stability

© AIRBUS China LTD. All rights reserved. Confidential and proprietary document.

April 2013Aircraft stability

Contents

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Aircraft ground stability1

Basic loading rules2

Aircraft CG limitations3



Contents

Page 3





Weight on NLGWeight on MLG

CG position

• Tip up limit definition• Cargo offloading



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CG position





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CG position



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CG position



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CG position



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CG position



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• Tip up limit definition• Passengers disembarking




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Tip up limit



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Tip up limit

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Tip up limit

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• Tip up detection

• In the cockpit: ECAM warning

• On ground: Nose strut extension

• At aircraft doors: Stairs/ramp misaligned

Stop loading/unloading cargo



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• Wind effect

Weight on MLG

Wind

Weight on NLG

LiftPitch up moment



Tip up limit

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• Wind effect

Weight on MLG

Wind

Weight on NLG

LiftPitch up moment



Tip up limit

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• Wind effect

Wind

LiftPitch up moment

Weight on MLGWeight on NLG



Tip up limit

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• Wind effect

Wind

LiftPitch up moment




Tip up limit

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• Wind effect

Wind

Lift

Pitch up moment




Tip up limit

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• Sensitivity to tip-up• Aircraft nose or tail heavy

A318A321

A320A340A300-600

A321 with ACTs

A319A330A380A310



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Page 23



Contents

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• Distributing the cargo load• Pyramid-shaped loading

• Place heavier loads closest to the wing box



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• Loading & offloading procedures

• An aft TOCG may improve takeoff/landing performance and handling, but in some cases (A320).....

It increases the risk of tail-tipping

Following simple rules during the process of loading and offloadingwill help preventing tail-tipping



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• Loading & offloading procedures• Golden rules

• Keep the maximum weight as forward as possible• On A320 avoiding loading & offloading passengers through the

rear passenger door

Load forward cargo hold before loading aft hold

Unload aft cargo hold before unloading forward hold

Loading/offloading cargo hold sequences:



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• Loading distribution• Passengers

• Make sure the number of passengers per section is correct• Make sure distribution of passengers per section is not extreme

• Cargo• Check for containers or pallets wrongly positioned• Check data on loading documents match the real load

• Nets• Check installation & condition of nets



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• In some cases, it may not be necessary to follow all of the above mentioned rules

… this is not a problem if you are aware of

- which rule has been broken

- the impact on the aircraft



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Contents

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• In addition to the risk of tail tipping, the CG location, both forward and aft, plays a vital role in aircraft manoeuvrability.• On the ground

• Structural and controllabity limitations


Takeoff Landing

Climb and cruise Approach

Go-around

• In the air• Manoeuvrability and stability


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• Takeoff limits summary

FORWARDNose gear strength (high TOW)Ability to rotateManoeuvrability+ elevator efficiencyMaximum elevator deflection+ extreme load factor

AFTMain gear strength (high TOW)Nose gear adherenceTail strike

Aircraft CG limitations on the ground3


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• Landing limits summary

FORWARDNose gear strengthManoeuvrability+ elevator efficiencyMaximum elevator deflection+ extreme load factorTHS stall limit

AFTMain gear strengthNeutral pointGo-aroundα-floor protection

Aircraft CG limitations on the ground3


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• In-Flight limits summary

AFTNeutral point1° per g Go aroundα-floor protection

FORWARDManoeuvrability+ elevator efficiencyMaximum elevator deflection+ extreme load factorTHS stall limit

Handling qualities / Structures

Aircraft CG limitations in the air3


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Conclusion

Controlled loading and offloading of passengers and cargo is

essential to avoid tail tipping

Simple basic rules to be followed

Aircraft CG impacts all phases of flight

Aircraft CG is critical to aircraft safety

Understanding aircraft CG improves safety


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© AIRBUS China LTD. All rights reserved. Confidential and proprietary document. This document and all information contained herein is the sole property of AIRBUS China LTD. No intellectual property rights aregranted by the delivery of this document or the disclosure of its content. This document shall not be reproduced or disclosed to a third party without the express written consent of AIRBUS China LTD. This document and itscontent shall not be used for any purpose other than that for which it is supplied. The statements made herein do not constitute an offer. They are based on the mentioned assumptions and are expressed in good faith.Where the supporting grounds for these statements are not shown, AIRBUS China LTD. will be pleased to explain the basis thereof.AIRBUS, its logo, A300, A310, A318, A319, A320, A321, A330, A340, A350, A380, A400M are registered trademarks.

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Thank you

Xie xie

谢谢

Documents

Aircraft stability on the ground - caac.gov.cnAircraft stability on the ground ... On A320 avoiding loading & offloading passengers through the ... Climb and cruise. · 2016-2-3