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Clearing the propeller wash before warm-up

Aviation Mechanic General (AMG) practice question 15 of 26 on Ground Operations and Servicing. ACS element AM.I.F.R10 · difficulty: standard. Want to answer it in a timed quiz? Use the Aviation Mechanic General (AMG) practice mode.

Question bank updated 2026-09-22

QUESTIONBefore warming up a reciprocating engine on the ramp, the mechanic must ensure that

  1. Athe cowl flaps are closed to shorten the warm-up.
  2. Bnothing is in the propeller wash.
  3. Cthe propeller is set to full high pitch for cooling.
Show the answer and explanation

Correct answer: B. nothing is in the propeller wash.

  • A — incorrect Cowl flaps are not closed for warm-up; they are kept open while operating on the ground.
  • B — correct The handbook says that when warming up the engine, personnel, ground equipment that may be damaged, and other aircraft must not be in the propeller wash.
  • C — incorrect Ground running is done with the propeller in full low pitch, not high pitch.

BACKGROUND

Ground operation of an engine near other aircraft or ground support equipment creates a blast hazard. The before-starting rules require that no property damage or personal injury result from propeller blast or jet exhaust, and the warm-up rules require that personnel, ground equipment that may be damaged, and other aircraft are not in the propeller wash. The engine is run with the propeller in full low pitch, headed into the wind, cowling installed, and cowl flaps open, while the instruments are closely monitored. For turbine aircraft the run-up area around the aircraft is likewise cleared of personnel and loose equipment.

STUDY TIP

Before any run-up, look behind the aircraft as well as ahead; the propeller wash and jet exhaust are where other aircraft and equipment get damaged.

KEY POINTS

  • Keep personnel, equipment, and other aircraft out of the propeller wash during warm-up.
  • Prevent damage or injury from propeller blast or jet exhaust before every start.
  • Run up with cowl flaps open and propeller in full low pitch.

SOURCES

  • FAA-H-8083-30B ch01 "Reciprocating Engines" (ground running and warm-up)
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SkyDrill is not affiliated with the FAA. This is an original practice item based on FAA-H-8083-30B Aviation Maintenance Technician Handbook – General, 14 CFR part 43 and part 65. Regulations and handbooks are revised; confirm details against the current edition.