PARKING BRAKE SYSTEM -PARKING BRAKE LEVER
EFFECTIVITY BEJ ALL 32-44-00
Page 9
D633W101-BEJ Jan 05/2002
PARKING BRAKE SYSTEM -PARKING BRAKE LATCH MECHANISM AND LATCH AND PEDAL POSITION SWITCHES
Purpose
The parking brake latch mechanism mechanically locks the brake pedals in the applied position.
These are the parking brake latch mechanism components:
*
Latching pawls (2)
*
Pawl stops (2)
*
Latch spring.
Two parking brake latch switches control the parking brake valve and parking brake indications.
Two pedal position switches control the brake-off light.
Location
The parking brake latch mechanism is in the forward equipment center below the captain’s rudder pedals.
The parking brake latch switches are on both sides of the latch mechanism.
The pedal position switches are on the captain’s and the first officer’s brake pedal cable quadrants.
Functional Description
When you push on the brake pedals and pull the parking brake lever up, the latching pawls hold the brakes in the applied position. The pawls engage stops on the captain’s left and right brake lower bellcranks.
The parking brake latch switches send signals to close the parking brake valve. They also send lever position data to AIMS and to the brake system control unit (BSCU) for control and indication.
The latch spring pulls the pawls up and releases the parking brake latch when you push the pedals forward.
When you release the brake pedals, the parking brake latch switches send signals to open the parking brake valve.
The pedal position switches turn on the brake-off light when both brake pedals are in the not-applied position.
EFFECTIVITY BEJ ALL 32-44-00
Page 10
D633W101-BEJ Sep 05/2002
PARKING BRAKE SYSTEM -PARKING BRAKE LATCH MECHANISM AND LATCH AND PEDAL POSITION SWITCHES
EFFECTIVITY BEJ ALL 32-44-00
Page 11
D633W101-BEJ Jan 05/2002
PARKING BRAKE SYSTEM -BRAKE METERED PRESSURE SWITCHES
Purpose
The brake metered pressure switches control the brake-on light when the airplane is on the ground.
Location
The right brake metered pressure switch is on the forward wall of the right main landing gear wheel well below the right autobrake shuttle and brake metering valves.
The left brake metered pressure switch is on the forward wall of the left main landing gear wheel well similar to the right.
Functional Description
When the left and the right switches sense high metered brake pressure, they turn on the brake-on light.
EFFECTIVITY BEJ ALL 32-44-00
Page 12
D633W101-BEJ Sep 05/2002
PARKING BRAKE SYSTEM -BRAKE METERED PRESSURE SWITCHES
EFFECTIVITY BEJ ALL 32-44-00
Page 13
D633W101-BEJ Jan 05/2002
PARKING BRAKE SYSTEM -PARKING BRAKE VALVE
Purpose
The parking brake valve closes to prevent brake accumulator pressure leakage through the normal antiskid valve modules.
Location
The parking brake valve is on the right main landing gear beam outboard of the right main gear trunnion. It is outboard and aft of the normal antiskid shuttle valve module.
Physical Description
The valve is a brushless dc motor-operated valve. It has a manual override lever to move the valve.
Functional Description
When the parking brake valve closes, it blocks the return lines from the normal antiskid modules. This prevents brake system pressure loss caused by internal leakage in the normal antiskid valve modules.
An internal switch in the valve sends position information to the BSCU and controls the parking brake close relay.
EFFECTIVITY BEJ ALL 32-44-00
Page 14
D633W101-BEJ Sep 05/2002
PARKING BRAKE SYSTEM -PARKING BRAKE VALVE
EFFECTIVITY BEJ ALL 32-44-00
Page 15
D633W101-BEJ Jan 05/2002
PARKING BRAKE SYSTEM -BRAKE STATUS INDICATION LIGHTS
General Parking Brake Set Light
Three brake status lights show people on the ground the The parking brake set light shows when the parking brake valve condition of the brakes. is in the closed position.
These are the three brake status indication lights:
*
Brake-off light
*
Brake-on light
*
Parking brake set light.
Location
The brake status indication lights are on the nose landing gear landing and taxi light brackets.
中国航空网 www.aero.cn
航空翻译 www.aviation.cn
本文链接地址：777 AMM 飞机维护手册 起落架 Landing Gear(47)
