Hydraulics Flashcards
What is the main source of hydraulic pressure for the hydraulic systems?
The No. 1 and No. 2 main hydraulic systems derive power from two engine-driven pumps, one on each engine.
What flow rate and pressure to the engine driven pumps provide?
9.5 gpm at 3000 psi
What is the purpose of the standby system?
To provide backup pressure for the No.1 & 2 hydraulic systems in the event of an engine-driven pump failure.
When will the STBY pumps operate with the STBY HYD switch set to normal?
When the flaps are out of the 0 degree position.
Where are the SPUs located? How are they powered?
No.1 is in the left main wheel well. No. 2 is in the rear bay.
Powered from the opposite side AC Gen. No. 2 can be powered from either as part of the ARPS mod.
What pressure can the standby pumps produce?
2900PSI
What does a HYD FLUID HOT light tell you?
Fluid over temp in the reservoir.
When will an ENG HYD PUMP caution light illuminate?
When the pressure drops below 2000PSI.
What does a STBY HYD PUMP HOT caution light tell you?
What can you do about it?
An overheat in the windings of the electric motors.
STBY HYD PUMP - NORM & Flap 0. Otherwise nothing.
Where is hydraulic reservoir quantity indicated?
Co-pilots instrument panel. This is the standby display not the primary.
What sub systems does #1 service?
Brakes, Flaps, Antacid, Inboard Roll Spoilers, Lower Rudder Actuator, PTU
What sub systems does #2 service?
Landing gear, Outboard roll spoilers, Nose wheel steering, Emergency brake/Parking brake, Upper rudder actuator.
Can hydraulic fluid supply ever be cut off from an EDP pump?
Yes, with the Pull Fuel Off handle.
How are the HYD reservoirs pressurized?
With a differential piston - maintained at approx 40PSI.
What is the purpose of the PTU?
To ensure gear retraction in the event of a No. 2 hydraulic system failure.
