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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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Landing gear
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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Landing gear
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