Hydraulic Power Flashcards
How many Hydraulic systems does the Q400 have, what do they power, and what are the power sources?
- They power Flight Controls, Landing Gear, Brakes, and Nose Wheel Steering. The Normal Power Souces are the two Engine Driven, Constant Pressure (3000psi), variable Delivery Pumps (EDPs), and the back up power sources are the AC Standby Hydraulic Pump, the PTU, a gas charged accumulator in conjunction with a DCMP (2600 - 3250 psi) and a hand pump.
What does the #1 Main Hydraulic System Power?
Flaps Anti Skid (Main Wheel Brakes) Inboard Roll Spoilers Rudder (Lower PCU) Elevators (Outboard PCU) PTU
What does the #2 Main Hydraulic System Power?
Landing Gear Outboard Roll Spoilers Nose Wheel Steering Emergency / Parking Brake Rudder (Upper PCU) Elevators (Center PCU)
What does the #3 Hydraulic System Power?
Left and Right Elevator (Inboard PCU)
What information is available in the Flight Deck, and where is it?
The Pressure and Quantitiy of the #1, 2, and 3 Systems, and the Parking Brake and STBY Hydraulic Pressures areindicated on the Co-Pilots MFD, or if disabled, in digital format on the Captain’s MFD. There is also indication of pump / valve activity on the Hydraulic Control Panel.
When does the STBY Hydraulic Pump activate?
- When you press the STBY HYD PRESS Switchlight
- No. 1 Engine Failure
- Flaps selected greater than 0° with the Parking Brake released.
(The Switchlight ON indication will only illuminate if the STBY PUMP is activated manually.)
Under what conditions does the PTU provide pressure to the #2 Hydraulic System, if selected on manually?
- The #1 EDP must supply normal pressure to the #1 System (#1 ENG HYD PUMP Caution Light out).
- The #2 System must have fluid.
Under what conditions does the PTU provide power automatically, on the ground?
(ON portion of Switchlight Illuminated)
- The #1 EDP must supply normal pressure to the #1 System (#1 ENG HYD PUMP Caution Light out).
- The #2 System must have fluid.
- Parking Brake Released.
- Flaps selected greater that 0°.
Under what conditions does the PTU provide power automatically, in flight?
(ON portion of Switchlight NOT Illuminated)
- The #1 EDP must supply normal pressure to the #1 System (#1 ENG HYD PUMP Caution Light out).
- The #2 System must have fluid.
- Flaps selected greater that 0°, OR
- The #2 hydraulic system has lost pressure, OR
- The #2 Engine Oil Pressure is Low.
What does the Green (/////) Bar indicate on the PTU Switchlight?
It indicates that the PTU is providing Hydraulic Power in either manual or automatic mode.
When will the PTU Fail portion of the PTU Switchlight illuminate?
When the PTU has failed to reach normal pressure, 5 seconds after being commanded automatically or manually.
Describe the HYD #3 ISOL VLV funciton.
- Opened manually by the HYD #3 ISOL VLV Switchlight.
- Opens automatically to maintain elevator control if either the #1 or #2 main systems fail, or both engines fail.
- Switchlight illuminates only if OPENed manually.
- ELEVATOR PRESS Caution Light Illuminates if selected on manually or if it fails open, and the #1 and #2 Main Systems are also supplying pressure to the Elevators.
What happens if the #1 Sytem loses pressure?
If the #1 Main System Pressure decreases below 2100 psi, the Priority Valve will close. This shuts off pressure to the - flaps and - PTU, and maintains pressure for the - elevators, - rudder, - inboard spoilers and - brakes.
Describe the #3 HYD System operation.
The #3 HYD System is a backup for the Elevators, in case the #1 or #2 HYD SYSs fail, or and enginge fails. It uses a gas charged accumulator to provide presure. The accumulator is maintained between 2600 and 3250psi by a DCMP. It is held in active standby by an ISOL VLV that is energized closed and that opens automatically or manually to account for a HYD or ENG failure.
When does the #3 STBY HYD PUMP Caution light illuminate?
If the #3 HYD SYS Accumulator falls below 900 psi, or if the DCMP runs for more than 60 seconds while on the ground.
Describe the #4 HYD SYS
- Used to Ensure the Main gear are down and locked.
- Uses a Hand Pump and an Auxilary Actuator.
- When you open the Landing Gear Alternate Extension Door on the Flight Deck floor, it closes the Alt. Lndg. Gear selector valve to allow pressure to build for the Aux. Acutator.
What are the Quantities for the HYD SYSs? What is needed for Dispatch?
- # 1 - 8 U.S. Quarts
- # 2 - 12 U.S. Quarts
- # 3 - 2.6 U.S. Quarts
- # 4 - 1.25 U.S. Quarts
- 40% for Dispatch.
Where is the #3 resevoirn and how is volumn indicated?
Environmental Compartment, up high, aircraft left. Gauge indication is in percent.
When does the #1 ISOL VLV close, what do you keep, and what do you lose?
The #1 ISOL VLV closes when inadequate fluid quantity is detected. Keep: - PTU - Rudder - Elevator - Flaps Lose: - Anti-Skid and Normal Brakes - Inboard Roll Spoilers
When does the #2 ISOL VLV close, what do you keep, and what do you lose?
The #2 ISOL VLV closes when inadequate fluid quantity is detected. Keep: - Elevators - Rudder Lose: - Outboard Roll Spoilers - Nose Wheel Steering - Landing Gear - Emergency / Parking Brake
Will the STBY HYD Pump Automatically activate in response to an EDP failure? Engine Failure?
#1 EDP Fail - No. #1 Engine Fail - Yes.
Will the PTU Automatically activate in response to an EDP failure? Engine Failure?
#2 EDP Fail - No. #2 Engine Fail - Yes.
Describe #1 or #2 HYD FLUID HOT.
- The HYD SYSs have oil-to-fuel heat exchangers.
- There is the tempurature controled bypass valve to control cooling of the HYD fluids.
- Each resevoir has 2 tempurature sensors.
- If the first detects and overtempurature condition, it illuminates the ## HYD FLUID HOT Caution Light and if the second resevoir sensor detects an overtem condition, it automatically closes the Firewall Shut-Off Valve (FSOV). to the EDP..
