failure, a hydraulic brake, mounted on the motor, prevents the
projectile tray from falling.
This concludes the introduction to the primary/backup hydraulic system.
The next part of the lesson is an introduction to the major components of
the primary/backup hydraulic system.
PART B - DESCRIPTION AND FUNCTION OF THE PRIMARY/BACKUP
HYDRAULIC SYSTEM AND COMPONENTS
Primary Hydraulic Pump.
The APU powers the primary hydraulic pump via a chain and sprocket
arrangement, and supplies hydraulic fluid to all hydraulic circuits
whenever the APU is functioning. This pump is a rotary-gear type pump
The primary hydraulic pump is capable of delivering 4.5
gallons per minute of flow at a system pressure of 1550 pounds per square
APU Driven Primary Hydraulic Pump.
Backup Hydraulic Pump.
The backup hydraulic pump is an engine driven pump that provides
hydraulic fluid to all hydraulic circuits if the APU or primary hydraulic
pump fails. This pump is a rotary-gear type pump connected to the power-
pack by a manually operated pump and