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Timing of a turbine engine ignition system

Aviation Mechanic Powerplant (AMP) practice question 5 of 11 on Ignition and Starting Systems. ACS element AM.III.H.K9 · difficulty: recall. Want to answer it in a timed quiz? Use the Aviation Mechanic Powerplant (AMP) practice mode.

Question bank updated 2026-09-22

QUESTIONHow is a turbine engine ignition system timed to the engine?

  1. AIt is timed to compressor rotation speed
  2. BIt is not timed to the engine cycle
  3. CIt is timed to each burner light-off
Show the answer and explanation

Correct answer: B. It is not timed to the engine cycle

  • A — incorrect Compressor speed governs the start sequence, but no timing of the spark to rotor position is required.
  • B — correct A turbine ignition system does not need to spark at an exact point in the operational cycle; it lights the fuel in the combustor and is then switched off.
  • C — incorrect Once combustion begins, the flame is continuous, so there is no repeated firing event to time.

BACKGROUND

Turbine ignition systems run mostly for a brief period during the start cycle, which makes them more trouble-free than a reciprocating engine ignition system. Because the flame is continuous once combustion begins, the system does not need to be timed to a point in the operational cycle; it ignites the fuel in the combustor and is then switched off. Continuous ignition, at a lower voltage and energy level, is selected for critical flight modes such as takeoff, landing, and some abnormal or emergency situations, in case of a flameout. The typical installation is a capacitor discharge system built as two identical independent units firing two igniter plugs, so the system is dual for safety.

STUDY TIP

Contrast the two engine types in one sentence: reciprocating ignition must be timed to the crankshaft, turbine ignition only has to light the fire and shut off.

KEY POINTS

  • Turbine ignition is not timed to a point in the engine cycle.
  • It is used for start and for continuous ignition at critical flight modes.
  • The typical system is dual, with two exciters and two igniter plugs.

SOURCES

  • sources/amp-powerplant/ch04.txt "Turbine Engine Ignition Systems"
Practice the Aviation Mechanic Powerplant (AMP) test →Timed 100-question exam, by ACS area, or review your misses. Free.
MORE ON IGNITION AND STARTING SYSTEMS

SkyDrill is not affiliated with the FAA. This is an original practice item based on FAA-H-8083-32B Aviation Maintenance Technician Handbook – Powerplant, and 14 CFR part 43. Regulations and handbooks are revised; confirm details against the current edition.