ALL-FINAL-MODULES-ASLG

Landing gear

The system that supports the aircraft during landing and while it is on the ground.

Fixed gear

Landing gear that is stationary and does not retract for flight.

Retractable landing gear

Landing gear that can be retracted into the fuselage or wings after takeoff.

Conventional gear

Also known as tailwheel gear, it is a landing gear configuration with two main wheels positioned under most of the weight of the aircraft and a smaller wheel located at the aft end of the fuselage.

Tricycle gear

A landing gear configuration with a shock-absorbing nose wheel at the forward end of the fuselage and the main wheels positioned behind it.

Center of gravity

The point at which the aircraft's weight is evenly distributed.

Ground-looping

A phenomenon where the aircraft loops or spins on the ground during landing or maneuvering.

NLG

Abbreviation for Nose Landing Gear.

MGL

Abbreviation for Main Landing Gear.

Downlock actuator

A mechanism that locks the landing gear in the down position.

Retraction actuator

A mechanism that retracts the landing gear into the fuselage or wings.

Shock absorber

A device that absorbs and dampens the impact forces during landing.

Hydraulic power

The use of hydraulic fluid to operate and control the landing gear system.

Differential braking

The use of brakes on one side of the aircraft to steer it during taxiing.

Bogie beam assembly

A structure that supports and connects the main wheels of the landing gear.

Pitch trimmer

A device used to adjust the aircraft's pitch attitude.

Door actuator

A mechanism that operates the doors of the landing gear bays.

Fairing

A streamlined covering or enclosure for the landing gear components.

Lock collar

A device that prevents the closure of the landing gear doors when the aircraft is on the ground.

Skid

A type of landing gear that helps slow the aircraft upon landing and provides directional stability.

Margin

The number of extra tires an aircraft may have in case one fails.

Bogie

The attaching mechanism that connects more than two wheels to a landing gear strut.

Tricycle-type landing gear

A landing gear arrangement where the main gear is attached to the reinforced wing structure or fuselage structure.

Fixed landing gear

Landing gear that remains exposed to the slipstream as the aircraft is flown and is not retractable.

Retractable landing gear

Landing gear that stows in fuselage or wing compartments while in flight and does not cause parasite drag.

Shock absorbing landing gear

Landing gear that alters and transfers shock energy throughout the airframe at a different rate and time than the single strong pulse of impact, and absorbs the shock by converting the energy into heat energy.

Leaf-Type Spring Gear

Landing gear that utilizes flexible spring steel, aluminum, or composite struts to receive the impact of landing and return it to the airframe to dissipate at a rate that is not harmful.

Rigid landing gear

Landing gear that directly transfers shock load to the airframe and uses pneumatic tires to soften the impact loads.

Bungee Cord

Elastic cords positioned between the rigid airframe structure and the flexing gear assembly to take up loads and return them to the airframe at a non-damaging rate.

Shock Struts

Self-contained hydraulic units that support an aircraft while on the ground and protect the structure during landing by absorbing and dissipating shock loads.

Shock strut

A component of an aircraft landing gear system that absorbs and dampens the impact forces during landing and taxiing.

Axle

A shaft on which the aircraft wheels are mounted.

Upper cylinder

The top part of a shock strut that contains a valve fitting assembly and is used for filling the strut with hydraulic fluid and inflating it with air or nitrogen.

Lower cylinder

The bottom part of a shock strut that is connected to the axle and provides support and stability to the landing gear.

Packing gland

A device used to seal the sliding joint between the upper and lower telescoping cylinders of a shock strut.

Wiper ring

A ring installed in a groove in the lower bearing or gland nut of a shock strut to prevent dirt, mud, ice, and snow from entering the packing gland and upper cylinder.

Torque links

Components attached to the upper and lower cylinders of a shock strut to keep the piston and wheels aligned and prevent rotation.

Locating cam assembly

A mechanism used in nose gear shock struts to align the wheel and axle assembly in the straight-ahead position when the strut is fully extended.

Shimmy damper

An external device attached to a nose gear shock strut to reduce or eliminate shimmy, which is an undesirable side-to-side oscillation of the landing gear.

Jacking points

Specific points on the shock struts where jacks should be placed for lifting the aircraft during maintenance.

Towing lugs

Attachments on the shock struts used for towing or positioning the aircraft.

Instruction plate

A plate attached near the filler inlet and air valve assembly of a shock strut that provides directions for filling the strut with fluid and inflating it.

Landing gear maintenance

The process of inspecting and maintaining various components of the landing gear system, including wheels, tires, shock struts, and steering mechanisms.

Wheel bearings

Bearings that support the weight of the aircraft wheels and allow them to rotate smoothly.

Lubrication

The process of applying grease or oil to reduce friction and wear on moving parts of the landing gear system.

Tapered roller bearing

A type of bearing commonly used in aircraft landing gear systems that consists of tapered rollers and a cone-shaped race.

Overtravel

The movement of the landing gear beyond its normal operating range, which must be checked and adjusted when necessary.

Landing gear latch

A mechanism used in landing gear systems to hold the gear up or down and/or to hold the gear doors open or closed.

Rigging and adjustment

Procedures that vary from aircraft to aircraft for adjusting and aligning landing gear components.

Uplock and downlock clearances

The specific distances or gaps required for the proper operation of the landing gear locking mechanisms.

Linkage adjustments

Fine-tuning the connections and movements of various components in the landing gear system.

Limit switch adjustments

Setting the limits or boundaries for the movement of certain parts in the landing gear system.

Manufacturer's maintenance data

Technical information provided by the aircraft manufacturer that outlines the specific procedures and requirements for maintaining and servicing the landing gear system.

Landing gear door latch

A specific type of latch used to secure the landing gear doors in the closed position.

Landing gear retraction test

A procedure to check the proper functioning of the landing gear system by raising and lowering the gear while visually inspecting for any issues or abnormalities.

Emergency back-up extension system

A secondary system that allows for manual extension of the landing gear in case of a failure in the primary system.

Annual inspection

A routine maintenance check performed once a year to ensure the overall airworthiness of the aircraft, including the landing gear system.

Landing gear linkages

The interconnected components that transmit motion and force between different parts of the landing gear system.

Landing gear extension and retraction

The movement of the landing gear from the extended (down) position to the retracted (up) position and vice versa.

Landing gear doors

Panels or covers that open and close to allow the extension and retraction of the landing gear.

Alternate/emergency extension or retraction systems

Backup systems that can be used to manually extend or retract the landing gear in case of a failure in the primary system.

Rubbing, binding, chafing, or vibration

Unusual sounds or sensations that may indicate a problem or malfunction in the landing gear system.