WHEEL BRAKE SYSTEM – GENERAL
The wheel brake system is composed by a brake assembly installed on each
main landing gear wheel. The system allows two different type of braking:
dynamic braking and static braking.
WHEEL BRAKE SYSTEM – MAIN COMPONENTS
PARK BRAKE CONTROL LEVER
The park brake control lever is a red lever positioned vertically. The lever
has to be pulled and turned clockwise to insert the park brake. On top of the
lever there is the white mark PULL AND TURN BRAKE.
RESERVOIR
The reservoir contains the hydraulic fluid of the circuit and is directly
connected to the brake master cylinders.
MASTER CYLINDERS (PILOT AND COPILOT)
The pilot left (right) master cylinders supplies the pressure necessary to
operate the left (right) brake of the main landing gear. When the pilot pushes
the left (right) brake pedal, the piston of the master cylinder extends and
removes the pressure from the brake. The (left and right) master cylinders of
the pilot are installed in series with those of the copilot.
When the pilot operates the brakes, the necessary hydraulic flow is supplied
through the related copilot master cylinder.
PARK BRAKE CONTROL VALVE
The park brake control valve is a direct-acting, mechanically operated valve.
The valve is designed to trap and maintain hydraulic brake pressure when
the helicopter is parked. The unit also provides automatic compensation for
change in hydraulic oil volume due to thermal variations or minor linkage in
the brake system. This is accomplished by means of spring loaded
accumulators.