The Aviation Mechanic Powerplant (AMP) written test is one of the FAA's mechanic knowledge tests. It covers piston and turbine engines and the systems around them: ignition, fuel, lubrication, fire protection, instruments, electrical power, air and exhaust systems, and propellers.
The format
- 100 multiple-choice questions, each with a single correct response (FAA-G-ACS-1).
- 2 hours to finish (FAA-G-ACS-1).
- 70 percent to pass (14 CFR 65.17; FAA-G-ACS-1).
The thirteen subjects
The FAA publishes the share of questions in each subject as a range. Reciprocating Engines and Engine Electrical Systems are each 5 to 15 percent of the test. The other eleven are 5 to 10 percent each: Turbine Engines; Engine Inspection; Engine Instrument Systems; Engine Fire Protection Systems; Engine Lubrication Systems; Ignition and Starting Systems; Engine Fuel and Fuel Metering Systems; Reciprocating Engine Induction and Cooling Systems; Turbine Engine Air Systems; Engine Exhaust and Reverser Systems; and Propellers (FAA-G-ACS-1).
What the questions are like
Many questions ask what a mechanic should do, check or expect. Examples from the subject areas: shutting down a turbine engine whose start has exceeded its EGT limit, what a red disc on a fire extinguisher's thermal discharge indicator means, or why a wet-sump oil system does not suit inverted flight. Others call for a calculation with every value given, such as a compression ratio, indicated horsepower, net thrust or bypass ratio.
Where the answers come from
The primary source is the FAA's Aviation Maintenance Technician Handbook for the Powerplant subjects, FAA-H-8083-32B. Inspection questions also draw on current 14 CFR, including parts 39, 43 and 91. The FAA's Aviation Mechanic ACS lists the knowledge elements the test can draw on, and its companion guide (FAA-G-ACS-1) gives the format and blueprint.
Handbook figures are for illustration
The handbook states that its engine procedures, pressures, temperatures and rpm figures are typical examples with no general application, so on a specific engine the manufacturer's instructions govern (FAA-H-8083-32B). That is a useful habit for the test too: when a question asks what governs the values on a specific engine, the answer is the manufacturer's instructions.
Practice FAA Aviation Mechanic Powerplant questions with explanations and timed mock tests.