Hydraulics Flashcards
What is on the Left Hydraulic System?
Rudder Ratio
Flight Controls
What is on the Right Hydraulic System?
Pitch Enhancement System
Flight Controls
Normal Brakes
What is on the Center Hydraulic System?
Flight Controls Flaps & Slats Tail Skid HDG Alternate Brakes Nosewheel Steering Gear
Tell me about the engine driven pump on the left hydraulic system.
The engine-driven pump is the primary pump of the left hydraulic system.
The pump controls are the engine pump switch and the respective engine fire switch on the fire control panel.
What are the Primary Pumps?
Left Engine, No 1 & 2 Center Electric, Right Engine
What are the Secondary Pumps?
Left Electric Demand, Air Demand, Right Electric Demand Pumps
When is the Engine Driven Pump in the left depressurized?
The pump is depressurized when the pump switch is off or when the fire switch is pulled.
Hydraulic OVHT light means what?
if the engine-driven pump casing temperature is too high
What does the ON switch do on the L ENG Primary?
The ON position activates the electric pump for continuous operation.
ON is not selected for normal operations.
What does the AUTO Selector do when engine starting?
For the left system, the demand condition occurs when the left engine driven pump output pressure is low.
The AUTO position is normally selected before engine start. This action makes the demand pump available throughout the flight.
What are the Four Pumps on the Center Hydraulic System?
2 Electric Driven Pumps - Pressurize the Center System
1 Air Driven Pump-
1 RAT
Tell me about the Air Dewmand Pump. (ADP)
Driven by bleed air and operates on demand only.
Failure of both electrical systems, ADP will provide pressure to the Center System. Must be in AUTO.
The Air Driven Pump provides an additional source of pressure to the Center system.
It is a high capacity pump that is driven by bleed air pressure from the center manifold of the pneumatic system.
Works when heavy loads are selected
Works when both center engine pumps have low pressure.
ADP has enough power to operate the HDG and the 11 essential components.
RAT
Can Pressurize Center System to get Flight Controls only when dual engine failure.
Can be manually deployed by pressing switch.
UNLKD: It has been deployed
PRESS: Adequate pressure is being created to power flight controls
-Must be above 130 kts for adequate pressure
Arms at 80 knots on takeoff
Has A/G logic to prevent deployment on Ground of Main Gear Tilt
What does QTY light mean
It has a QTY light to indicate low fluid level.
Tell me about the Center 2 Primary Electric Hydraulic pumps
The two electric hydraulic pumps provide the primary power for the center hydraulic system.
Two switches labeled ELEC 1 and ELEC 2 are used to control the pumps.
When the aircraft is parked, these pump switches are normally OFF.
Both of these switches are normally switched ON before engine start.
Why do I have just one Center Primary Electric Hydraulic light on
When only one electrical power source is available and both Center motor pumps are selected ON, the number 2 pump is inhibited to reduce the electrical load.
Therefore, with both pump switches selected to ON, the number 2 pump will show a PRESS light until a second electrical power source is made available.
What happens with the standpipe?
C1 pump receives fluid from below the standpipe level of the center reservoir. Alternate brakes are in the center system. If quantity is sensed low in the center system reservoir, an isolation valve automatically closes to direct the C1 pump to only pressurize the Alternate Brake components and Nosewheel steering.
This automatic isolation provides RESERVE brake operation through the alternate brakes on the 767.
When ADP is used to power HDG-what happens with the flaps?
The speed of retraction and extension is reduced.
When do you get a green PRESS light in the RAT switch?
When the RAT delivers adequate hydraulic pressure.
When is automatic RAT deployment inhibited?
automatic RAT deployment is inhibited below 80 kts., at taxi speeds and below, in order to keep the RAT from deploying after engine shutdown at the gate.
Hydraulic Quantity Display;
At or below ____ a QTY indication is presented
.50
Hydraulic Quantity Display;
A QTY above ____ is required for dispatch?
RF
RF Is Approx 75%
Hydraulic Quantity Display;
1.22 or more show _____ for _____and requires MX action.
OF- overfill
Overheat message for the Center system primary pumps is_______
C HYD 1 OVHT and C HYD 2 OVHT for the #1 and #2 primary electric pumps respectively.
