Landing Gear

TTP	B1-L3	ATA32
Cessna 172	B2-L1

   

                 

Fixed, tubular spring, steel main gear struts that are bolted into the fuselage bottom. Attached to the outboard end of each strut is a die-cast aluminum wheel and disc brake assembly.

Steering nose wheel that is linked through the rudder pedals to give ground control.

Shock Strut - The shock strut is made of top and bottom machined cylinders that contain a mixture of oil and air. The top and bottom cylinders give changes in the shock-absorb rates.

Torque Links - The torque links give a mechanical link between the top and bottom parts of the shock strut and help to keep the nose wheel aligned with the airframe.

Nose wheel Steering - operates through the use of the rudder pedals. The spring-loaded steering rod assemblies connect the nose gear steering arm assembly to the arms on the rudder pedals. The steering gives up to approximately 10 degrees each side of neutral, after which the brakes can be used to get a maximum deflection of 30 degrees right or left of the center.

Shimmy Damper ( Lord Shimmy Damper) - The shimmy damper uses rubber with a lubricant to absorb nose wheel vibration. The damper is connected between the shock strut and the steering arm assembly.

Shimmy Damper gives resistance to shimmy when it moves hydraulic fluid through the small orifices in a piston. The damper is connected between the shock strut and the steering arm assembly.

Hydraulic brake system is comprised of two master cylinders, located immediately forward of the pilot’s rudder pedals, brake lines and hoses, and single-disc, floating cylinder brake assemblies located at each main landing gear wheel.

Parking brake system is comprised of a pull-type handle and mechanical connections which are linked to the rudder pedal assembly. Pulling aft on the brake handle applies mechanical pressure to the rudder pedals, activating the brakes and locks the handle in place. Turning the handle 90 degrees will release the parking brake and allow for normal operation through the rudder pedals.

Brake operation is accomplished by pushing on the upper part of each rudder pedal. This motion is mechanically transmitted to the respective brake master cylinder, and through fluid-carrying lines out to the brake assembly where fluid pressure acts to exert friction (through brake pads) against brake discs.

Brake Line Removal -Brake lines in the system are mostly metal, with flexible rubber lines installed near the master cylinders. Rigid lines may be replaced in sections using pre-formed parts available from Cessna. Flexible lines should be inspected for cracks, deterioration wear and damage, and are also available in replacement assemblies through Cessna.

Brake System Cessna 172 

PTP Cessna 172	B1	LOC	FOT	SGH	R/I	MEL	TS
	B2	LOC	FOT	SGH	R/I	MEL	TS

321002 Main Gear Spring Assemblies - Examine for cracks, dents, corrosion, condition of
paint or other damage. Examine for chips, scratches, or other damage that lets corrosion
get to the steel spring. Examine the axles for condition and security.B 05-12-02 721, 722
321007 Inspect main landing gear axle.
322001 Nose Gear - Inspect torque links, steeringrods, and boots for condition and security
of attachment. Check strut for evidenceof leakage and proper extension.
Check strut barrel for corrosion, pitting, andcleanliness. Check shimmy damper and/or
bungees for operation, leakage, and attach points for wear and security.
322003 Nose Gear Fork - Inspect for cracks, general condition, and security of attachment.

C 05-12-04 720
322004 Nose Gear Attachment Structure - Inspect for cracks, corrosion, or other damage and security of attachment.
322006 Nose gear trunnion, steering assembly, torque link assembly, nose gear fork and
axle. Make sure you inspect these areas: 1. Nose gear trunnion surface. 2. Steering collar
and steering collar attach bolt. 3. Torque link, torque link attach pin and attach bolt. 4.

Nose gear fork. 5. Nose gear axle.
324001 Brakes - Test toe brakes and parking brake for proper operation.

B 05-12-02 230
324002 Brakes, Master Cylinders, and Parking Brake - Check master cylinders and parking
brake mechanism for condition and security. Check fluid level and test operation

of toe and parking brake.
324003 Brake Lines, Wheel Cylinders, Hoses,Clamps, and Fittings - Check for leaks, condition, and security and hoses for bulges and deterioration. Check brake lines and

hoses for proper routing and support.
324004 Tires - Check tread wear and general condition. Check for proper inflation.
324005 Wheels, Brake Discs, and Linings - Inspect,for wear, cracks, warps, dents, or other
damage. Check wheel through-bolts and nuts for looseness.
324006 Wheel Bearings - Clean, inspect and lube.

 SHIMMY DAMPER – SERVICING PROCEDURE

                               

(1) Remove the shimmy damper from the airplane.

(2) While you hold the damper in a vertical position with the fitting end pointed down, pull the fitting end of the damper shaft to its limit of travel.

(3) While you hold the damper in this position, fill the damper through the open end of the cylinder with hydraulic fluid.

(4) Push the shaft up slowly to seal off the filler hole.

(5) Clean the damper with solvent. Make sure that the shaft comes out through the filler hole until the damper is installed on the aircraft.

(6) Install the damper on the airplane.

Shimmy damper cleaning

(1) Clean the shimmy damper with a clean, lint-free cloth to prevent the collection of dust and grit.

(2) Make sure that the part of the damper piston shaft that you can see is always clean.

(3) Clean the machined surfaces of the shimmy damper.

(a) Use a clean, lint-free cloth soaked with hydraulic fluid to clean the machined surfaces.

(b) After the surfaces are clean, remove the remaining hydraulic fluid from them with a clean, lint-free cloth.

Shimmy Damper Servicing (On Airplanes with the Lord Shimmy Damper)

                 Lord Shimmy Dampers do not need special servicing. However, you must lubricate the nose wheel shimmy damper pivots with general purpose oil MIL-L-7870.

 Shimmy damper cleaning

(1) Clean the shimmy damper with a clean, lint-free cloth to prevent the collection of dust and grit.

(2) Make sure that the part of the damper piston shaft that you can see is always clean.

(3) Clean the machined surfaces of the shimmy damper with a clean, lint-free cloth to prevent the collection of dust and dust.

C. If necessary, exercise a shimmy damper before installation.

(1) If a shimmy damper has been in storage for a long period, make sure that it moves freely before you install

CAUTION: Make sure that you do not push or pull on the shaft of the shimmy damper after it has reached its limit in either the up or the down position. If you continue to push a fully

compressed, bottomed-out shaft, you can cause damage to the shimmy damper. If you

continue to pull on a fully extended shaft, you can cause damage to the shimmy damper.

(2) If the shimmy damper does not move freely, push and pull the shaft through complete cycles until it does move freely. When the shimmy damper shaft has come to its limit of travel up and down as you push and pull, make sure that you do not continue to push or pull it beyond that limit of travel