When must continuous ignition be used during operations?

Continuous ignition must be used during takeoffs and landings on contaminated runways as a precautionary measure to mitigate the risk of engine flameout or difficulties with engine performance that could occur due to reduced airflows or potential water ingestion. Contaminated runways can have conditions such as ice, snow, or standing water, which may cause unexpected changes in aircraft performance and handling. By engaging continuous ignition during these critical phases of flight, the crew ensures that the engines maintain reliable operation despite the challenging conditions.

The use of continuous ignition is particularly important during takeoffs and landings when the aircraft is transitioning through varying speeds and configurations. This added layer of precaution enhances safety and provides the flight crew with a better safety margin during these crucial operational phases.