BOMBARDIER BD-100-1A10, Руководство по эксплуатации

Страница: 445 / 544

LANDING GEAR
Sep 13/2004 Flight Crew Operating Manual Volume 2
REV 1 CSP 100-6
15-01-11
TIRES AND BRAKES
DESCRIPTION
The Challenger 300 uses dual wheel assemblies and brakes on each main landing gear. The speed limit of all tires is 182 kt.
The nose gear has two wheels and uses chine tires to eject the ground water away from the aircraft engines.
To prevent tire burst, each main wheel has four heat sensitive fusible plugs. They melt when heat buildup in the wheel/tire
assembly exceeds a preset value, permitting the tire to deflate safely.
The PARK/EMER BRAKE handle, located on center pedestal, is controlled from within the flight compartment. Anti-skid
is not available when utilizing emergency brakes.
Wheel and brake overheat protection is provided by the MLG bay overheat detection system and indicated by CAS mes-
sages.
COMPONENTS AND OPERATION
Each wheel of the main landing gear is equipped with self-adjusting multidisc carbon brakes that provide stable braking
control under all operating conditions.
The brake control system is partitioned into two separate braking channels. One channel controls the braking and anti-skid
operation for the inboard wheels while the second controls the outboard wheels. Each braking channel is powered by an
independent hydraulic system and an independent electrical power source. The brake control system provides brake pres-
sure application, antiskid protection, touchdown protection, locked wheel crossover protection, gear retract braking and
pressure control functions.
The system is armed when the landing gear is selected down or when ground mode is detected, by energizing the inboard
and outboard shutoff valves, permitting hydraulic pressure to reach the inboard and outboard brake control valves. Ground
mode is established by confirmation of either left or right weight on wheels inputs from the proximity sensors that indicates
ground for more than 5 seconds or when wheel spin-up of greater than 50 kts is achieved. Full braking authority and dif-
ferential braking is available to both the pilot and copilot. The brake control unit (BCU) uses the greater input of the two
for the pedal brake command. The system provides low initial pressure gain to provide suitable pedal force to brake torque
characteristics for adequate directional control during taxi.
Each braked wheel is fitted with a wheel speed transducer. The BCU monitors the wheel speed transducers to provide in-
dependent ant-skid protection down to 10 kts to each of the main wheels and to determine wheel speed thresholds for spin-
up override and locked wheel crossover protection. The BCU also uses the wheel speed transducers to provide wheel speed
outputs for spoiler and thrust reverser deployment.
The BCU commands a brake pressure of 350 psi for 4 seconds during gear retraction to ensure the main wheels have
stopped spinning as they enter the main landing gear bay.
The shutoff valves hydraulically disarm the BCS by removing hydraulic pressure to the brake control valves during flight
when the following requirements have been met:
- Weight-off -wheel on both main landing gears
- Landing gear handle is up
- Wheel speeds and velocity reference equal zero
Two brake wear indicator pins installed on each brake assembly provide a visual indication of brake wear. Before conduct-
ing the visual indication of the brake wear indicator pins, the parking brake must be set. Service the brakes when the end
of the wear indicator pin is flush with the top of the indicator housing.
NOTE: The brake wear indicator pins must be checked with the brakes applied and the left and right hydraulic systems
pressurized.
REV 1