When must continuous engine ignition be used?

• A. Takeoff and landing on contaminated runways
• B. Flight through moderate or heavier rain
• C. Flight through moderate or heavier turbulence
• D. Flight in vicinity of thunderstorms

Answer: (A)

Continuous ignition is provided to keep a stable flame in the engine when conditions make flame-out or surge more likely, especially during critical phases of flight. The scenario that requires it is takeoff and landing on a contaminated runway, where water, slush, or debris can be ingested or disrupt the combustion process as thrust changes rapidly. Keeping the igniters on during these moments helps ensure the engine remains lit and reduces the risk of an uncommanded shutdown at a vulnerable time. In other listed conditions, ignition may be considered based on procedures or operator guidance, but the mandatory situation highlighted here is contaminated-runway takeoff and landing.