Landing Gear Flashcards
L/G UNDERCARRIAGES
And oleo (oil and air) strut is a pneumatic hydraulic shock absorber
Sustain long periods in a static load condition (parked)
Absorb impact of landing and related drag and side load (landing load condition)
Control the recoil of the landing
Strut dikme demek
Oleo (ail&air)
Bogie: iki teker arası yatay eleman. Dönüşleri uzun alıyoruz ki bogie’lere çok fazla yük binmesin.
The oil supplies damping
Nitrogen supplies spring function
Nitrojenin olma nedeni korozyon oksidasyon olmaması.
Torque links
Landing gear torque links are used to prevent rotation of the landing gear piston in the oleo strut
Safety pins*
Aircraft downlock pins are used to lock the landing gear in place
In some aircraft, there is protection device to avoid the landing gear being inadvertently retracted on the ground. It consist of: A latch located in the landing gear lever.
The pilot may be prevented from retracting the landing gear whilst the aircraft is on the ground by: THE ELECTRICAL CONTROL SYSTEM BEING ROUTED THROUGH THE WEIGHT ON WHEELS SWITCH
Latch: kilit.
Ağırlık swichleri sayesinde
Pilot landing gearları yerdeyken geri toplamasını engellemesi için uçağın ağırlık swichleri engel olur.
Emergency gear extension can be performed
With compressed nitrogen
By mechanical manual means
By freefall
By hydraulic system
Overcentre
Iniş takımlarının kilitlenmesi için kullanılan prensip
Tubeless Tyres:
Only nitrogen inside
No internal friction
Lower risk of bursting
Less weight than tube tyre
Ply rating- index of tyre strength
Tyre treads - provide indication of wear, grip, and means of displacing water
Yağmurlu havalarda sert iniş - positive landing
Çok sert - hard landing
Aquaplaning - hydroplaning
Thermal plug - if the wheel becomes excessibely hot the fusible material melts, releasing the air pressure and tyre deflate - wheel rims
The reason for fitting thermal plugs to aeroplane wheels is that they prevent tyre burst after excessive brake application.
Isınan havayı dışarı deşarj ediyor. Fazla basıncı bu şekilde tahliye eder.
Tyre creep - tendency for the tyre to slip (rotate) about wheel
(Circumferential movement of the tyre in relation to the wheel flange)
Tyre wear
- it is very important that inflation pressures are kept at the correct level
Under inflation leads to wear at the SHOULDERS
Over inflation leads to wear at the CROWN
Tyre treads may be repaired several times however damage to sidewalls and plies is not acceptable.
Çok şişkin olduğunda göbekten eriyor, az basınçta kenarları eriyor.
Shimmy Damper
shimmy - oscillation of the nose wheel from side to side on the ground (has potential to cause damage)
Nose wheel shimmy may be described as a possibly damaging vibration of the nose wheel when moving on the ground
Shimmy occurs on the nose wheel landing gear during taxiing when the wheels tend to describe a sinusodial motion on the ground
This effect is overcome by means of an accumulator associated with the steering wheel cylinder
Ön tekerin sağ sol titremesi, Vto’nun altında lövyeyi kaldırıp biraz basıncı düşürebiliriz.
Hydroplaning
Occurs when tyre loses contact with surface and slides on a thin film of water
If depth of water is greater than 3 mm possibility of hydroplaning is high
Hydroplaning speed (kt) = 9 √(tyrepressure psi)
During hydroplaning, the friction coefficient between tyre and rwy surface is approximately 0
1 bar = 14.5 psi
Operational Considerations
Ground maneuvring - imposes greates stress on wheel assembly, so taxi slowly. Use minimal breaking and largest turn radius possible
Wheel fires: can occur if brakes are very hot and oil or grease is present.
Use dry powder to extinguish
Only appr wheel from front or rear. Not the side in case sidewall blows out.
Types of wheel brakes
Mechanical drum brakes - very old ac and cars
Hydraulic expander brakes - old ac
Pneumatic bag brakes - old ac
Single disc - light ac
Multi disk - airliners
Multiple disc brakes are manufactured from steel or carbon fiber
