Main and Nose Gear Fairing Doors

T-34C AIRCRAFT SYSTEMS FAMILIARIZATION

CHAPTER NINETEEN

WORKBOOK

Nose Gear Centering Pin

The nose gear centering pin, located on the right side of the nose landing gear shock strut returns

the nose wheel to the center position as it is retracted, allowing the wheel to fit into the wheel

well. It also keeps the nose wheel centered when the shock strut is extended and the aircraft is

airborne to allow for a smoother touchdown upon landing. The centering pin only works when

there is no weight on the nose wheel and the strut is extended.

Shimmy Dampener

The shimmy dampener (Figure 19-2) is a small shock absorber located on the left side of the

nose landing gear shock strut that dampens out nose wheel vibrations during takeoff or landing.

Main and Nose Gear Fairing Doors

The main and nose gear fairing doors, which coincide with the gear movement, finalize the

covering of the gear wheel wells when retracted to provide a smooth aerodynamic surface.

When the gear is lowered actuating rods from the landing gear gearbox open the main gear

inboard doors, the main gear extends into place, and the actuating rods close the doors. When

the gear is raised, the reverse occurs. The main gear fairing doors attached to the strut move up

and down with the strut. The nose gear fairing doors consist of a panel attached to the nose gear

strut, and doors on the left and right side of the wheel well. These doors are closed by the

movement of the nose strut itself, and opened by the opposing spring action of a torque tube as

the strut begins to exit the wheel well.

Downlocks

Downlocks are located on both the nose and main landing gears to lock the landing gear in the

extended position and prevent unintended retraction of the gear when the aircraft is on the

ground. The nose gear is held down by mechanical advantage (locking action of gears in

gearbox), and an over center pivot (joining of bottom of V-brace and top of side/drag brace).

The main gear are held down by mechanical advantage, overcenter pivot, and positive

downlocks. When the main gear is down, the lock is held in position by a cable attached to the

main gear inboard door. When retracted, the positive downlock is removed by opposing spring

action. A mechanical downlock is not needed on the nose gear, since it does not experience the

large lateral forces sensed by the main gear on landing.

Uplocks

Uplocks are used to prevent unintended movement of the landing gear out of the wheel well

(landing gear "sag" or "creep"). The nose and main gear are held in the retracted position by

mechanical advantage and a positive uplock. On the main gear the positive uplock is held in

position by a cable attached to the main landing gear inboard door and removed by opposing

spring action. On the nose gear the uplock consists of an uplock receptacle (hole in an aft facing

metal tab) at the bottom of the shock strut and a torque tube operated by the landing gear

gearbox. When the gear retracts, the torque tube rotates a latch (hook) into the uplock

LANDING GEAR SYSTEMS 19-5