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A&P General oral: free sample

10 oral questions from across the General subjects. Say each answer out loud, reveal the model answer, and tick the key points you hit. The real oral is closed book and needs 70% of the whole section.

questions
10
questions
book, like the real oral
Closed
book, like the real oral
to pass the real oral
70%
to pass the real oral

Free practical project guide

Read and interpret aircraft electrical circuit diagrams, and symbols, including solid state devices and logic functions.

Fundamentals of Electricity and Electronics · AM.I.A.S7 · paper task

What you are likely to be given

An aircraft wiring diagram or schematic from a maintenance manual (or a testing supplement figure) containing protective devices, switches, relays, solid-state devices or logic gates, and a question about how the circuit works.

The standard to meet

Each symbol is named correctly, current is traced from the source through protection and control devices to the load and ground, and the circuit's response to the given switch, relay or logic input condition is stated correctly.

Steps

  1. 1Identify the kind of diagram: a schematic shows how the system works, not where parts are; a wiring diagram shows the coded wiring; a block diagram shows a simplified relationship.
  2. 2Read the title, notes and legend, check the model and revision, and note how wire crossovers and connections are drawn.
  3. 3Find the power source (battery or bus) and the ground symbols.
  4. 4Trace the path from the source through the fuse, circuit breaker or current limiter, then through switches and relay contacts to the load.
  5. 5For each relay, find the coil (X1, X2), work out what energizes it, and which contacts (NO or NC) close when it is energized.
  6. 6Identify solid-state devices: diode direction (anode to cathode) and transistor type (emitter arrow out is NPN, in is PNP).
  7. 7For logic gates, apply the gate rules (AND, OR, NAND, NOR, exclusive OR, inverter) and check whether the manufacturer states positive or negative logic.
  8. 8State what the circuit does for the given condition and where you would measure to confirm it.

Where to look

  • AMT General (FAA-H-8083-30B), ch. 4, p. 4-11 to p. 4-13 (Diagrams: installation, schematic, block, wiring)
  • AMT General (FAA-H-8083-30B), ch. 4, p. 4-24 (Figure 4-29, electrical symbols)
  • AMT General (FAA-H-8083-30B), ch. 12, p. 12-23 and p. 12-24 (schematic representation of components and wires)
  • AMT General (FAA-H-8083-30B), ch. 12, p. 12-120 to p. 12-122 (logic polarity, basic logic circuits, integrated circuits)
  • FAA-CT-8080-4G, Appendix 1, Figure 15 (p. 1-15), FAA-CT-8080-4G, Appendix 1, Figure 16 (p. 1-16) and FAA-CT-8080-4G, Appendix 1, Figure 18 (p. 1-18) for practice reading aircraft circuits

Safety

  • Use the diagram for the correct model, serial range and latest revision: the reading procedure starts with checking the model affected and the latest change letter.

Common mistakes that fail the project

  • Treating a schematic as if it showed where components are located in the aircraft.
  • Misreading a wire crossover as a connection (or the reverse).
  • Mixing up the normally open and normally closed relay contacts.
  • Confusing NAND with AND or NOR with OR outputs.

Practice questions

Like the two questions the examiner asks during each project. The practical is open book, so knowing where to look counts.

Q1. Does this schematic show where the components are located in the aircraft?Reveal

No. A schematic locates components with respect to each other and shows the principle of operation; an installation diagram shows where they are located.

AMT General (FAA-H-8083-30B), ch. 4, p. 4-11

Q2. A two-input AND gate in this circuit has one input high and one input low. What is the output?Reveal

Low. An AND gate output is high only when all of its inputs are high.

AMT General (FAA-H-8083-30B), ch. 12, p. 12-121

Q3. How do you tell an NPN transistor symbol from a PNP symbol?Reveal

By the arrow on the emitter: pointing out is NPN, pointing in is PNP.

AMT General (FAA-H-8083-30B), ch. 12, p. 12-106

FAA sources

  • AMT General (FAA-H-8083-30B), ch. 4, p. 4-11
  • AMT General (FAA-H-8083-30B), ch. 4, p. 4-13
  • AMT General (FAA-H-8083-30B), ch. 4, p. 4-19
  • AMT General (FAA-H-8083-30B), ch. 4, p. 4-24
  • AMT General (FAA-H-8083-30B), ch. 12, p. 12-23
  • AMT General (FAA-H-8083-30B), ch. 12, p. 12-33
  • AMT General (FAA-H-8083-30B), ch. 12, p. 12-106
  • AMT General (FAA-H-8083-30B), ch. 12, p. 12-121