landing gear word

8/19/2019 Landing Gear Word

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Landing gear

Dr. Tarak Othman

Mohamed ashraf Madboly

David Sameh zakher

Ahmed Adel mostafa

2nd aeronautical


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Landing gear

General types of landing gear :

tailwheel-type landing

gear (Conventional) Tricycle landing gear

Tandem Gear , Boeing B-52


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Landing gear

considerations:Design

•

Landing Gear should locatenear the center gravity (CG)

of the plane


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Landing gear

Specifications landing gear:

• Comfortable shock absorption

• Short stopping distance (braking)

• High rolling stability during ground maneuvering

• Small storage volume

• Low drag (specially for fixed landing gears)

• High reliability and safety

• Low maintenance

• Low weight


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Materials :

• Composites will be integrated into gear because they

are stronger and cheaper than the current used high

strength steels and titanium • Ultra-High Tensile Steels are already being integrated

into the A400M and the B-787 landing gear, replacingthe low-alloy steels.

• Research into organic matrix composites and metal

matrix composites using titanium are promising, thoughstill very expensive.

Gear:Fixed and Retractable Landing

Fixed : gear is attached to the airframe

and

remains exposed to the slipstream as

the aircraft is flown.

Retractable : Retractable

landing gear stow in fuselage

or wing compartments while in

flight.

As the speed of the aircraft

increases,

the drag caused by the landing

gear becomes greater and a

means to retract the gear to

eliminate parasite drag is

required,


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Landing gear

Shock-Shock Absorbing and NonAbsorbing Landing Gear :

•

Shock Absorbing : the shockenergy is altered and transferred

throughout the airframe at a

different .rate and time than the

single strong pulse of impact,

•

Non-Shock Absorbing : the

shock is absorbed by

converting the energy into

heat energy.

Constriction:


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Landing gear

:AlignmentLanding Gear

:SupportLanding Gear

a)

Parallel to the longitudinal axis (aligned) b)

Converge on the longitudinal axis (tow-in)

c) Veer away from the longitudinal axis (tow-out)

Aircraft landing gear are attached to thewing spars or other structural members.

Retractable gear must be engineered in

such a way as to provide strongattachment to the aircraft and still be

able to move into a recess or well when

stowed. The trunion is a fixed structural

extension of the upper strut cylinderwith bearing surfaces that allow the

entire gear assembly to move.


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Landing gear

:RetractionLanding Gear

Retraction Systems

The simplest contains a lever in the flight deck mechanically

linked to the gear. Through mechanical advantage, the pilotextends and retracts the landing gear by operating the lever. Use

of a roller chain, sprockets, and a hand crank to decrease therequired force.

To decrease drag in flight some undercarriages retract into thewings and/or fuselage with wheels flush against them surface or

concealed behind doors; this is called retractable gear.


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Landing gear

Hydraulic power system :


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Emergency Extension Systems :

The emergency extension system lowersthe landing gear if the main power systemfails.

Some aircraft have an emergencyrelease handle in the flight deck that is

connected through a mechanical

linkage to the gear up locks. When the handle is operated, it

releases the up locks and allows thegear to free-fall to the extended

position under the force created by

gravity acting upon the gear.

Other aircraft use a non-mechanical

back-up, such as pneumatic power, tounlatch the gear.


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Landing gear

• http://www.slideshare.net/rishikeshims/aircraft-landing-gear-system

• http://www.slideshare.net/partyrocka99/landing-gear-for-aircraft

•

http://www.aviationworld.me/vb/t41.html

• http://army-tech.net/

• https://en.wikipedia.org/wiki/Landing_gear

• Book : Aircraft Landing Gear Systems ch 13

Reference:

http://www.slideshare.net/rishikeshims/aircraft-landing-gear-systemhttp://www.slideshare.net/rishikeshims/aircraft-landing-gear-systemhttp://www.slideshare.net/partyrocka99/landing-gear-for-aircrafthttp://www.aviationworld.me/vb/t41.htmlhttp://www.aviationworld.me/vb/t41.htmlhttp://army-tech.net/https://en.wikipedia.org/wiki/Landing_gearhttps://en.wikipedia.org/wiki/Landing_gearhttps://en.wikipedia.org/wiki/Landing_gearhttp://army-tech.net/http://army-tech.net/http://www.aviationworld.me/vb/t41.htmlhttp://www.aviationworld.me/vb/t41.htmlhttp://www.slideshare.net/partyrocka99/landing-gear-for-aircrafthttp://www.slideshare.net/partyrocka99/landing-gear-for-aircrafthttp://www.slideshare.net/partyrocka99/landing-gear-for-aircrafthttp://www.slideshare.net/rishikeshims/aircraft-landing-gear-systemhttp://www.slideshare.net/rishikeshims/aircraft-landing-gear-systemhttp://www.slideshare.net/rishikeshims/aircraft-landing-gear-system


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Landing gear

Note:

This dimension sheet is not the same as the S.W design.

( we got from the calculations "Non-Logic Piston diameter ",so we had to

change the dimension) .


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Landing gear

landing gear word

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