HYDRAULIC POWER SUPPLY AND SYSTEMS
This chapter discusses the hydraulic power supply and systems installed on the aircraft. The
information is designed to provide you with an understanding of these systems to aid in
understanding operating procedures and limitations.
The hydraulic power supply system supplies hydraulic pressure to operate the flaps, speed
brakes, power brakes, and landing gear. Two engine-driven variable displacement hydraulic
pumps are used to supply the hydraulic operating pressure. Each engine drives one pump. In the
event of an engine failure, either pump is capable of operating all the hydraulically operated
A pressure relief valve and a bypass valve are incorporated to relieve any excessive hydraulic
The hydraulic power supply system includes three hydraulic fluid filters, a bleed air filter, and a
pressurized reservoir for fluid storage to ensure an adequate supply of fluid under all flight
conditions. Shutoff valves are incorporated to stop hydraulic fluid flow in an emergency.
501. ENABLING OBJECTIVE
Recall the basic description, related components and systems, limitations, and functions of the
hydraulic power supply system.
502. ENABLING STEPS
List the hydraulically powered systems.
Recall conditions required for illumination of the HYD LEVEL LO annunciator.
Describe the effects of a single hydraulic pump failure.
State the indications of flap asymmetry.
Recall all flap operating limits.
Discuss the operation of the speed brake system.
List the subsystems of the landing gear system.
Recall the power source for normal and emergency gear extension.
Discuss emergency gear extension.
HYDRAULIC POWER SUPPLY & SYSTEMS