Hydraulic Power Flashcards
Describe the components of the #1 Hydraulic system.
The #1 hydraulic system has an engine driven pump on the #1 engine propeller reduction gear box.
An electrical standby pump serves as the backup for the #1 system. This pump can be powered by either 115volt AC bus.
It also provides power to the Power Transfer Unit (PTU).
What systems are powered by the #1 Hydraulic system?
Flaps Anti-skid brakes Inboard spoilers Rudder Elevator PTU
Describe the components of the #2 Hydraulic system.
The #2 hydraulic system has an engine driven pump (EDP) on the #2 engine propeller reduction gear box.
The PTU which relies on pressure from the #1 system to pressurize the #2 system serves as a back up to the EDP.
What systems are powered by the #2 Hydraulic system?
Landing gear Outboard spoilers Nose steering Emergency brakes Rudder Elevator
Describe the #3 hydraulic system.
The #3 hydraulic system serves as a backup for elevator control in the event of the failure of either or both primary hydraulic systems.
Pressure is maintained in a gas charged accumulator by a DC Motor Pump (DCMP). The DCMP maintains the accumulator pressure between 2600 to 3250psi.
Describe the fourth hydraulic system.
The fourth hydraulic system is an alternate means of extending the main landing gear. A manual pump located in the cockpit can be used to extended the MLG.
What are the reservoir quantities for the hydraulic systems?
1 - 8qt
2 - 12qt
3 - 2.6qt
4 - 1.2qt
When will the Standby pump automatically activate?
If the #1 engine fails or then the flap selection lever is moved out of the 0 position with the parking brake off.
When will the PTU automatically activate?
On the ground: #1 EDP is producing normal pressure. #2 system has fluid Parking brake off Flaps selected more than 0
In the air: #1 EDP is producing normal pressure. #2 system has fluid
and
Flaps selected more than 0 or #2 system has lost pressure or #2 engine oil pressure is low
When will the #3 isolation valve automatically open?
Either or both of the #1 or #2 main systems fail.
or
Both engines fail.
Which systems has isolation or priority valves?
Both systems have isolation valves and the #1 system has a priority valve.
How do the isolation valves work?
The isolation valve will close if the system loses quantity.
The #1 system will still power: Elevator Rudder Flaps PTU
The #2 system will still power:
Elevator
Rudder
How does the priority valve work?
If the #1 system pressure drops below 2100psi it will de-power the PTU and flaps.
How is hydraulic fluid temperature controlled?
Both primary systems have a oil to fuel heat exchanger located in the collector bays which regulate fluid temperature.
Why would the #3 STBY HYD PUMP CWP light illuminate?
If the DCMP has been running for longer than 60 seconds on the ground or if the accumulator pressure falls below 900psi.
