Oral Prep - Hydraulic Flashcards
How are the primary flight controls actuated?
Hydraulic power.
The rudder system is powered by which hydraulic system?
All three systems.
How many hydraulic systems are on the CRJ?
3
The CR2 has how many hydraulic systems? In cruise flight you experience a left engine failure. How many hydraulic systems are lost? How many hydraulic pumps are lost? Will the ACMPs that are selected to AUTO come on in this situation? What will cause them to become operative? On the overhead Hydraulic Panel, what is different about 9 the 3A switch? What is unique about where 3B can get electrical power? During single engine taxi with the left engine operating, if you select the 1B pump ON will it operate?
There are three systems with two pumps each. System one and two have an engine driven pump, EDP, mechanically driven by the accessory drive of the engine, and a backup electrically driven ACMP, powered from the opposite side IDG. Therefore losing one engine will take out two pumps, the EDP for that engine and the backup ACMP for the opposite system that is powered from the IDG driven by the failed engine. Due to redundancy the loss of one engine results in the loss of two pumps but all three hydraulic systems are still powered. System 3 has two ACMPs with 3A as the main pump. The 3A switch has only two selections, ON & OFF, whereas the rest have ON, OFF, & AUTO. The B pumps do not automatically turn on after an engine or EDP failure. They may be manually selected ON inflight so long as their respective bus is powered and the associated generator is operating. On the ground an interlock circuit allows the B pumps to operate when the applicable B switch is turned ON even though the associated generator is not operating. When deployed the ADG automatically energizes ACMP 3B regardless of switch position, powering the primary flight controls.
Which of the hydraulic systems have engine driven pumps as well as electric pumps?
Systems 1 and 2
What does the AUTO position on the HYD 1, 2 and 3B do?
Causes the B pumps to operate when their respective bus is powered, the associated generator is operating and the flaps are not at 0°
Do the B pumps activate automatically after an engine failure?
No
What happens to ACMP 2B if the left engine fails?
Cross side ACMPs are load shed when the opposite side generator fails
Which ACMPS run continuously during normal operations?
3A & 3B, (since the AD)
How is hydraulic system fluid cooled?
Systems 1 & 2 are cooled by a ram-air/oil heat exchanger and system 3 hydraulic pumps are located in the wheel well area and do not require dedicated cooling.
With both IDGs operating and pumps 1B and 2B selected to the AUTO position, when will the pumps operate?
When the flaps are out of the 0° position.
Which hydraulic pump automatically operates from the ADG Bus during ADG deployment?
Pump 3B.
How does the crew know there is adequate hydraulic fluid quantity?
By checking the HYD synoptic page and verifying fluid quantities are green
What is the Normal/usual Hydraulic quantities?
Green quantity indications.
If the left engine fails or is shutdown, which hydraulic pumps will be unavailable?
Pumps 1 EDP and 2 B.
