Pumps 1 deliver hydraulic fluid from tank 2 to the hydraulic system and to pressure accumulator 4. Under normal braking operation, the brakes are applied by means of valve 3. When the brake pedal is depressed, fluid from the main hydraulic system of the plane or from accumulator 4 is delivered through valve 3 and switchover valves 5 to disk brakes 6, braking the wheels. The system provides for braking both wheels at once or for braking the right and left wheels separately. When the brakes are released, the fluid is discharged from the cylinders of brakes 6 through valve 3 back to tank 2. Accumulator 4 has relief valve 7. Valve 3 consists of two identical units in a single housing. In addition to the hydraulic system, the brakes can also be operated by an independent emergency pneumatic system. When lever 8 is turned, compressed air from tank 9 passes through valve 10 to switchover valves 5, which switch off the hydraulic mains and admit the air to the cylinders of brakes 6, performing the braking operation. When the brakes are released, the air is discharged through the same pipelines and valve 10 to the atmosphere.
$4298$CHP,Br$