amt 124

The Wright Flyer, for instance, took off from a ____ and landed on ____.

rail
skids

soon after the basic problems of flight were solved, attention was turned to providing better _____ and ____of the aircraft while it was operated on the ground.

control
stability

______ and _____ wheels were first used, which in turn, gave way to specially designed landing gear and wheels that absorbed the extreme loads imparted during takeoffs and landings.

Bicycle
motorcycle

were installed to provide safer and more efficient control for slowing an airplane after landing.

braking systems

were provided to allow the landing gear to be stowed during flight to reduce aerodynamic loads, or drag.

retraction systems

The first airplanes with wheels used a ______

tricycle landing gear

In a tricycle gear configuration, the main wheels are located _____ the center of gravity and an auxiliary wheel (nose wheel) is located at the _____ of the aircraft.

behind
front

was used in order to keep the propeller further above the ground.

tail-wheel landing gear

This configuration became so popular that it is called "conventional" landing gear, even though it has the disadvantage of being difficult for ground.

tail-wheel landing gear

The most prevalent arrangement on modern aircraft is the _____

tricycle gear configuration

are configured with the two main wheels located ahead of the aircraft's center of gravity and a much smaller wheel at the tail.

Tailwheel aircraft

are highly susceptible to ground loop

Tailwheel aircraft

Prior to World War II, almost all airplanes used the _______.

tailwheel-type landing gear

During WWII such airplanes such as the_______, the _____, and the _____, as well as the commercial ______, proved that the tricycle gear configuration was superior in ground handling ease.

Lockheed Lightning
Consolidated Liberator
Boeing Superfortress
Douglas DC-4

is seldom used on civilian aircraft other than gliders.

tandem wheel arrangement

The main wheels are located in line under the fuselage and outrigger wheels support the wings.

tandem landing gear

produced by the friction of the airflow over the structure

parasitic drag

is caused by the production of the lift.

induced drag

Parasitic drag ______ as the speed increases

increases

induced drag _______ as the speed increases because of the lower angle of attack required to produce the needed lift

decreases

Non-absorbing gear include _____, ____, ____, and _____ construction.

spring steel
composite
rigid
bungee cord

do not absorb shocks but rather accept the energy in some form of elastic medium and return it at a rate and time that the aircraft can accept.

spring steel and composites

transmit all the loads of landing touchdown directly to the airframe's structure.

rigid landing gear

Some aircraft use rubber to cushion the shock of landing.

bungee cord

The most widely used shock absorber for aircraft

oleo strut

The cylinder of this strut is attached to the aircraft structure, and a close fitting piston is free to move up and down inside the cylinder.

oleo strut

Aircraft wheels must be _____ and _____ .

lightweight
strong

Most wheels are made of either _______ or ______

aluminum
magnesium alloys

the most critical part of a wheel.

bead seat area

is the half of a two-piece wheel that houses the brake.

inboard wheel half

bolts to the inboard half and holds a shrunk-in bearing cup in which a bearing is installed.

outboard wheel half

cushions aircrafts weight force on the ground

shock absorbers

types of shock absorbers (3):

1. rigid struts

2. steel struts

3. oleo pneumatic shock absorber

1. air

2. hydraulic fluid

3. flow metering pin

4. orifice

shock absorber compressed = ______

on ground

shock absorber extended = _______

in flight

types of extension & retraction (4);

• mechanical link

• electrically operated

• electric-hydraulic

• hydraulic

main landing gear retracts ______

inboard

nose landing gear retracts ______

forward

extension sequence for landing gear

doors open - landing gear extends - doors close

retraction sequence for landing gear

doors open- landing gear retracts - doors close

engages when the landing gear is fully retracted into the fuselage

uplock

engages when the landing gear are fully extended

downlock

prevents accidental extension of landing gear

safety valve

uses gravity for the landing gear during loss of hydraulics, loss of landing gear control unit, or electrical control.

gravity extension

safety features (4);

1. downlock

2. uplock

3. safety valve

4. gravity extension

landing gear types (5);

• fixed landing gear type

• retractable landing gear type

• ski type

• skid type

• float type