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Subject area K of 15

Aircraft Electrical Systems

5-10% of the A&P Airframe test, about 5 to 10 of the 100 questions. The FAA's test standard lists 17 knowledge elements and 9 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.K.K1Generators, DC generation systems, and DC power distribution systems.
  • AM.II.K.K2Alternators, AC generation systems, and AC power distribution systems.
  • AM.II.K.K3Starter generators.
  • AM.II.K.K4constant speed drive (CSD) and integrated drive generator (IDG) systems and components.
  • AM.II.K.K5Voltage regulators and over-volt and overcurrent protection.
  • AM.II.K.K6Inverter systems.
  • AM.II.K.K7Aircraft wiring sizes, types, selection, installation and circuit protection devices.
  • AM.II.K.K8Derating factors in switch selection.
  • AM.II.K.K9Aircraft wiring shielding.
  • AM.II.K.K10Aircraft lightning protection.
  • AM.II.K.K11Instrument or instrument panel removal and installation.
  • AM.II.K.K12Aircraft lighting systems.
  • AM.II.K.K13Electrical system troubleshooting.
  • AM.II.K.K14Soldering preparation, types of solder, and flux usage.
  • AM.II.K.K15Aircraft electrical connectors, splices, terminals, and switches.
  • AM.II.K.K16Electrical system measurement, adjustment, and testing.
  • AM.II.K.K17Aircraft battery troubleshooting and maintenance.

Risk management: hazards you must be able to spot and manage

  • AM.II.K.R1Testing/troubleshooting electrical systems or components.
  • AM.II.K.R2Connecting or disconnecting external power.
  • AM.II.K.R3Maintenance on energized circuits/systems.
  • AM.II.K.R4Maintenance in areas containing aircraft wiring.
  • AM.II.K.R5Routing and securing wires and wire bundles.
  • AM.II.K.R6Selecting the size of wire in an electrical circuit.
  • AM.II.K.R7Selection or installation of wire terminals.
  • AM.II.K.R8Effects of soldering.
  • AM.II.K.R9Soldering practices.

Try a sample question

Aircraft Electrical Systems ยท AM.II.K.K16

You have installed a new bonding jumper between an equipment rack and structure, after removing the paint under the terminal. What resistance should the finished connection not exceed, and what kind of instrument is needed to check it?

Practice all of aircraft electrical systems

The full course has questions on every element listed here, with an explanation and FAA source for each.

See the courseFree mock test