Day 1 Lecture Flashcards
Fixed Landing Gear Purpose
Simple Design and Lightweight
Fixed Landing Gear are used for ____ powered aircraft
Recip
Fixed Landing Gear are not worried about ____ because they have ____ ____
Drag
Low Speed
Retractable Landing Gear Purpose
No Drag
Retractable Landing Gear are used on ____ ____ aircraft
Higher Speed
Most aircraft equiped with retractable Landing Gear are _____
Commercial
There are 6 configurations
Conventional
Tricycle
Seaplanes/amphibians
Skiplanes
Helicopter
Multiple wheeled
There are ____ Tandem and ____ Tandem Rows of landing gears.
Single
Double
Conventional Design Now incorporates a ______
tailwheel
Conventional Design ____ ____ carried majority of weight
Main Gears
Conventional Design Originally has “___ ___” on rear for stability for unpaved runways
tail skid
Conventional Design C.G. _____ wheel
behind
Conventional Design have ____ ____ for turning “S” Turns and Ground Loops!!
Differential Braking
Most common in use for transport aircraft
Tricycle Design
Tricycle Design C.G. is between ____ and ____ wheels
Main
Nose
What design Allows for heavier aircraft
Tricycle Design
What design Utilizes Nose Wheel Steering for turns
Tricycle Design
Hull watertight (Corrosion Largest Concern)
Landing Gear retract into fuselage
Amphibians
Wheels replaced with FLOATS
Aluminum or fiberglass
Rudders installed on back of floats for water taxi
Seaplanes
Used for artic or snow operations
Wheels replaced with SKIS
Aluminum or fiberglass
Some may incorporate retractable skies
Skiplanes
Most common design
Hydraulic dampeners may be used for shock absorption
Can incorporate ground handling wheels
Skid-Type
Helios that are not exposed to landing in unimproved areas
Caster-type nose wheel (tricycle design)
Fixed-wheel gear
Military and Heavy transport (possible)
Retractable-wheel gear
2 wheels attached to a beam on one strut
Seldom one bogie is used
Bogie
2 Bogies
Strut consist of an Air/Oil design (OLEO)
Truck
Usually used with Tricycle design
Heavy weight applications
Two or more wheels per strut
Multiple Wheeled Landing Gear
Also Called Shock Cord
Small airplanes (rubber band with fabric covering)
Requires special tooling to replace cords
Bungee Cord
So called “Cessna Type Gear Legs”
Made of Spring Steel
Leaf Type
Most common (and complex) type for Transport
Absorb heavy impact on landing and taxiing
Shock Strut (OLEO)
Compressible – absorbs shock during taxiing
Dry and non- combustible
Keeps strut extended (static)
Amount of Chrome showing (air in strut)
air
Incompressible – Fluid Contained in bottom chamber
Piston rises due to landing forces fluid through metered orifices to upper chamber (dynamic)
Oil
Designed to control the flow of fluid from one chamber to another.
Metering Pin or Plunger
Cheveron Seal– Prevents oil from escaping(one way)
Wiper/Scraper – keeps debris out of strut
Seals
Simple and Complex design (Aircraft use Complex)
Uses Air (N2) and Oil (usually MIL-H-5606)
Shock Strut Construction
Check for leakage, proper air pressure, and cleanliness IAW AMM
Lint-free cloth moistened with proper hydraulic fluid to wipe down exposed chrome
Shock Strut Maintenance
Medium Pressure (A)
Valve Core (similar to auto)
High Pressure (B)
No Valve Core Schrader Valve
AIR VALVES
Fluid level extremely low or entrapped air
Follow Aircraft AMM/Service manual for proper procedure
Typical Procedure
Construct a bleed hose to make an airtight connection to filler opening (tool part number)
Jack aircraft until struts extended
Release air pressure and remove air valve assembly
Fill strut to proper level with proper hydraulic fluid
Attach bleed hose and insert free end into a container of clean hydraulic fluid
Place exerciser jack under strut, compress and extend strut (allow to extend with own weight)
Remove jack and bleed hose, install air valve and inflate strut
Bleeding/ Servicing Shock Struts
Shock Strut Troubleshooting no chrome exposed while plane is still
Low Nitrogen
Shock Strut Troubleshooting Strut “bottoms out” during landing
Shock Strut Troubleshooting Strut “bottoms out” during taxiing
Low Nitrogen
