Subject area F of 15
Hydraulic and Pneumatic Systems
5-10% of the A&P Airframe test, about 5 to 10 of the 100 questions. The FAA's test standard lists 11 knowledge elements and 5 risk management elements for this area. Here is every one, plus sample questions to try.
What the FAA tests
From the aviation mechanic test standard, FAA-S-ACS-1.
Knowledge: what you must know
- AM.II.F.K1Hydraulic system components and fluids.
- AM.II.F.K2Hydraulic system operation.
- AM.II.F.K3Hydraulic system servicing requirements.
- AM.II.F.K4Hydraulic system inspection, check, servicing, and troubleshooting.
- AM.II.F.K5Pneumatic system types and components.
- AM.II.F.K6Pneumatic system servicing requirements.
- AM.II.F.K7Servicing, function, and operation of accumulators.
- AM.II.F.K8Types of hydraulic/pneumatic seals and fluid/seal compatibility.
- AM.II.F.K9Hoses, lines, and fittings.
- AM.II.F.K10Pressure regulators, restrictors, and valves.
- AM.II.F.K11Filter maintenance procedures.
Risk management: hazards you must be able to spot and manage
- AM.II.F.R1Relieving system pressure prior to system servicing or disassembly.
- AM.II.F.R2High pressure gases and fluids.
- AM.II.F.R3Storage and handling of hydraulic fluids.
- AM.II.F.R4Cross-contamination of hydraulic fluids.
- AM.II.F.R5Compatibility between hydraulic seals and hydraulic fluids.
Try a sample question
Before checking hydraulic quantity on a large transport, the maintenance manual requires the spoilers retracted, landing gear down with doors closed, thrust reversers retracted and parking brake accumulator pressure at a minimum value. What can happen if the reservoir is serviced with the airplane in another configuration?
Practice all of hydraulic and pneumatic systems
The full course has questions on every element listed here, with an explanation and FAA source for each.