Hydraulics Flashcards
What are the components of the No. 1 Transfer Module? Which logic module controls the first stage tail rotor shutoff valve?
This module has a transfer valve, a pressure switch, a first stage primary servo shutoff valve, a first stage tail rotor shutoff valve, a restrictor, and check valves. / No.1 Logic Module (WP0026 Isolation Block Diag)
What are the major components of the hydraulic system?
The major components of these systems are three hydraulic pump modules, two transfer modules, a utility module, a pilot-assist module, three primary servos, a tail rotor servo, four pilot-assist servos, an APU accumulator, an APU handpump, and a refill handpump.
Describe the function of the depressurization valve on the backup pump module?
A depressurization valve in the backup pump module allows the motor to get up to rated speed before a load is applied. When the backup pump motor is turned on, the depressurization valve in the backup pump module destrokes the output pressure of the pump to 700 psi. This valve is held open by the logic module in the right relay panel for four seconds when either the APU generator or external power is supplying power, or for 1/2 second when the helicopter generators are supplying power. After the pump motor is started, the valve closes, allowing the pump to develop between 3000 and 3100 psi output pressure.
Are shutoff valves depicted open or closed in the hydraulic schematics? (Hint: You may have TROUBLE finding this.)
Open (WP 1718) Figure 1
What protects the hydraulic system from fluid loss if the pressure line to the APU accumulator ruptures?
Velocity fuse
Does the pilot-assist module require replacement if the pressure reducer indicator button is popped?
- Turn on backup hydraulic system to reset button. Check that button resets. a.If button resets, go to Step 2. b.If button does not reset, replace pilot-assist module (WP 1007). Go to Step 4.
- Do not engage/disengage solenoids or run No. 1 or No. 2 hydraulic systems. Go to Step 3.
- Run backup hydraulic system for two (2) minutes. If button is popped, replace pilot-assist module (WP 1007). Go to Step 4.
- Procedure completed.
What are the Three basic qualities of Hydraulics?
Incompressible, Expansion/contraction, pressure transmission
What are the authorized types of Hydraulic fluid?
Petroleum: MIL-H-5606
Synthetic Base: MIL-H-83282
What does the hydraulic systems provide?
Hydraulic pressure to operate the primary servos, tail rotor servos, pilot assist servos, and AUX power unit (APU) start motor.
What are the components of the hydraulic system?
Three hydraulic pump modules, two transfer modules, utility module, three dual primary servos, one dual tail rotor servo, pilot assist servos, APU accumulator, APU hand pump, and servicing hand pump
How is complete redundancy accomplished?
Complete redundancy is accomplished by the backup pump providing hydraulic power to both NO. 1 and/or No. 2 systems if one or both pumps fail.
What can be expected if two systems lose pressure?
Slight reduction in the max rate of flight control movement due to only one pump supplying both stages with hydraulic power.
Each pump has three internal check valves, where are they located?
External ground coupling, pressure side, return side
What caution lights are brought on by the NO 2 hydraulic logic module?
RSVR 2 Low, Backup RSVR LOW
During a No 1. RSVR LOW, the NO 1 Hydraulic logic module is responsible for bringing on the backup pump.
FALSE
