Section XIII – Hydraulics Flashcards
Under what circumstances would a PRESS light illuminate on a Left Hydraulic Primary Engine Driven Pump switch?
The primary pump PRESS light illuminates and the EICAS advisory message L HYD PRIM PUMP displays when the pump output pressure is low.
Upon performing the FO’s before start flow, you observe a PRESS light illuminated on the Primary C2 center hydraulic system pump. In addition you observe a C HYD PRIM 2 EICAS message. Given this information, what action would you need to take?
No action necessary. The C2 pump may be load shed automatically to reduce electrical loads with the C1 pump operating on the ground. You may see an associated EICAS message C HYD PRIM 2
Describe a scenario where the Left Hydraulic Electric Demand Pump is inhibited?
To reduce electrical load, the left electric demand pump is inhibited on the ground during engine start of either engine, when only one electrical generator is operating. The left demand pump and SYS press may illuminate when starting engines on the ground.
What scenario would cause a “QTY” light to illuminate on the hydraulic overhead panel?
The light illuminates when the reservoir quantity is low.
How could one interpret that a hydraulic reservoir quantity is not sufficient for flight?
By observing a “QTY” OR “RSVR” light on the Hydraulic Panel, and also by observing a magenta ‘RF’ on the lower EICAS status page adjacent to the associated hydraulic system.
When would the center hydraulic demand pump (ADP) automatically operate on the ground or in flight with the associated selector in AUTO?
Center air demand pump operates automatically when both center electric pump pressures are low, or when heavy load items are selected (flaps/slats, landing gear).
List some items that are powered by the Left Hydraulic System.
a. Flight Controls (including spoilers) b. Stabilizer Trim ( one of the modules )
c. Rudder Ratio (9.20.8)
d. Left Auto Pilot Servo
e. Left Thrust Reverser (-200 only) f. Right Yaw Damper
Upon performing the FO’s preflight procedure, you observe an UNLKD light illuminated on the Ram Air Turbine switch. What action should you take if any?
a. Contact maintenance. The light indicates that the RAT is not stowed and locked.
List some items that are powered by the Center Hydraulic System.
a. Flight Controls (including spoilers)
b. Nose Wheel Steering
c. Flaps and Slats
d. Alternate Brakes
e. Landing Gear
f. HDG
g. Tail Skid (-300 aircraft)
h. Left Yaw Damper
i. Stab Trim ( one of the modules )
g. Center Autopilot Servo
List some items that are powered by the Right Hydraulic System.
a. Flight Controls (including spoilers)
b. Normal Brakes
c. Pitch Enhancement System (PES)
d. Right Autopilot Servo
e. Right Thrust Reverser (-200 only)
T/F: The RAT is inhibited from manual deployment on the ground.
False; it is prohibited from AUTO deployment on the ground.
In the event of a Center System hydraulic leak, will nose wheel steering capability be lost?
The reservoir maintains reserve hydraulic fluid for the use of brakes and steering in the event of a center system hydraulic leak. In addition, the center number one electric primary hydraulic pump is isolated to provide hydraulic pressure to the reserve brakes and steering system.
From which hydraulic system does the Hydraulic Driven Generator receive hydraulic pressure? When would it automatically be powered?
It receives pressure from the Center Hydraulic System. It would automatically operate when electrical power is lost from both AC busses.
With the Ram Air Turbine deployed in flight, how could you interpret that it is producing sufficient hydraulic pressure?
Once the RAT is producing pressure, a PRESS light illuminates on the RAT switch.
When would a hydraulic ACMP run continuously ?
In the ground mode the right ACMP will run continuously whenever the slats are commanded to takeoff either by the flap handle or the alternate position selector and slat arming switches, as sensed by the flap / slat electronics unit.
Can reserve brakes work without selecting the reserve brakes / steering switch ?
The center number one electric primary hydraulic pump is automatically isolated, if system quantity is sensed low, to provide hydraulic pressure to the reserve brakes and steering system INFLIGHT only.
