Straight from the Ground School Manual, minus the drawings
The static braking is achieved through a parking brake handle located in the Landing Gear Control Panel which is used to trap pressure provided by the brake pedals by operating, through a push-pull cable, a parking brake valve such to keep the brake assembly engaged.
Pressure is trapped by operating a shuttle valve provided with two check valves. A spring loaded pin locks the push-pull cable in the engaged position every time the handle is pulled. To remove the locking action is required to push left brake pedal such that the hydraulic pressure overcome the spring load of the locking pin which retracts and allows cable movement.
A hydraulic accumulator in the parking brake valve is provided for each hydraulic pipeline to compensate for fluid leaks and/or pressure changes due to temperature effect.
The parking brake valve can keep the helicopter parked for at least 8 hours on a ground with a 12% slope with a change of temperature of 45°C (to be confirmed). A pressure switch in installed on each hydraulic pipeline
supplying the brake assembly. A position microswitch is installed in the parking brake valve.
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