Rotor Brake

Question 1

Rotor Brake

Answer 1

Brake disc bolted to No. 8 sync shaft at rear of c box

3 piston hydraulic brake caliper bolted to airframe over disc and manual operated hydraulic master cylinder is mounted to cockpit overhead panel. Hydraulic fluid is supplied from reservoir located aft of forward gearbox

Electrical interlocks on ECLs prevent brake application at high engine power, mechanical interlocks prevent ECLs from being moved forward when brake is engaged

Question 2

Rotor Brake Arming Lever

Answer 2

Mounted on ECL quadrant, marked ROTOR BRAKE - ARM/DISARM

At ARM, lever inserts mechanical lock preventing ECL from being advanced beyond GROUND position. Lever also de energizes the depressurization valve, closing the valve and allowing master cylinder to pressurize the fluid.

At DISARM, depressurization valve is energized open and all fluid pressure is dumped to the reservoir. Mechanical lock in throttle quadrant is removed, allowing ECLs to move to FLIGHT

To remove rotor brake, place lever into stowed position (DISARM) which will release pressure in rotor brake, releasing the pucks

Question 3

Rotor Brake Operation

Answer 3

Arming lever set to ARM

Depress squeeze grip on lever handle, move handle forward to apply brake pressure. I full forward position the handle will lock into place

Action of moving lever forward moves a piston within master cylinder, causing rotor brake hydraulic fluid to pressurize and operate brake caliper

2 pressure switches (one on brake caliper and another on master cylinder) illuminate ROTOR BRAKE ON light when pressure exceeds 15psi

Third mechanical switch illuminates ROTOR BRAKE ON light when handle is out of stowed position

Question 4

Rotor Brake - Normal Application

Answer 4

Apply brake below 40% RRPM with light to moderate pressure. Set brake handle fully forward after rotors have come to a complete stop if rotors are to be locked. Rotor brake applications below 35% should not be rapid.

Question 5

Rotor Brake - Alternate Application

Answer 5

May be used if ground bounce (padding) is experienced.

ECLs... STOP
ROTOR BRAKE lever... ARM
APPLY... brake at 70% RRPM
RELEASE... at 60% RRPM
RRPM at 25%... apply brake again until rotors stop.

following use of rotor brake, a minimum interval of 15 minutes must be allowed before subsequent application