Fire in Flight
An in-flight fire is a "land now" emergency, with three distinct sub-types — engine, electrical, and cabin — that differ in how they're recognized and how they're fought. The common thread: get on the ground as soon as practical, isolate the source, and accept that any landing site you can reach is preferable to flying with an uncontained fire.
Treat any in-flight fire as immediately threatening. Smoke that you can smell or see in the cabin is a fire that has already established somewhere; the rate at which it can become unsurvivable is measured in minutes, sometimes seconds. The procedure here is general — your POH emergency checklist is the authoritative source for your specific aircraft.
Engine fire
An engine fire is most likely during start, but can occur in flight from a fuel leak, oil leak onto hot exhaust, or mechanical failure.
General response (verify in your POH — procedures vary):
- Execute the engine fire emergency shutdown per POH — typically mixture to idle cut-off, fuel valve off, magnetos off, master off (in that aircraft-specific order).
- Enter autorotation — once the engine is off, you're descending under autorotation regardless of intent.
- Land immediately — any clear area within glide range. Don't try to reach a better field if it costs you altitude.
- Evacuate after touchdown and rotor stop. Move upwind, away from the aircraft.
Some helicopters have engine fire detection systems with an annunciator; many do not. In aircraft without detection, recognition comes from smoke, smell, oil/fuel smell, or visible flame from the engine cowling.
Electrical fire
Electrical fires are usually preceded by the smell of burning insulation, and often by a circuit breaker popping or visible smoke from an avionics stack.
General response:
- Master switch OFF — removes power from the bus, isolating the source. This is the single most effective action for an electrical fire.
- All avionics OFF — secondary action to ensure no live circuits remain.
- Ventilate the cabin — open vents or windows to clear smoke. Beware that on some aircraft, opening vents can feed an active flame; the smoke-versus-flame trade-off is in your POH.
- Land as soon as possible. "As soon as possible" is more lenient than "immediately" — you can choose a better landing site, but don't continue to destination.
- If possible, isolate the failed circuit by turning off individual avionics or pulling specific breakers (POH-specific). Do not reset a popped breaker on a circuit suspected of fire.
The trade-off with master-off: you lose your radio, intercom, transponder, and any electric instruments. If you've made an emergency call, get position and intentions out before flipping the master.
Cabin fire
Cabin fires are caused by passenger or cargo items igniting (rare but documented), electrical fires that breach into cabin space, or fuel/hydraulic leaks reaching cabin sources of ignition.
General response:
- Identify the source if possible — visible flame is treated differently than smoke without visible flame.
- Use a fire extinguisher if installed. Most light helicopters carry a small Halon or dry-chemical extinguisher; aim at the base of the flame.
- Ventilate — open vents or windows. The trade-off between fanning a flame and clearing smoke depends on whether the fire is contained or spreading; visibility to fly the helicopter is the priority.
- Land immediately — even more aggressively than electrical fire. A cabin fire near the pilot is a few breaths from incapacitating.
- Evacuate after touchdown. Move upwind. If you can, take the extinguisher with you.
"Land now" vs "land soon"
Fire procedures distinguish levels of urgency. The general taxonomy:
- Land immediately — engine fire, cabin fire, any uncontained flame. The next clear area is the best one. Do not weigh "could I make it to the airport" against ground risk.
- Land as soon as possible — electrical fire after master-off, contained smoke. You can pick a better field, but don't fly to destination.
- Land as soon as practical — smoke gone, situation under control, abnormal but stable. Typically used for residual concerns after a primary emergency.
The phrasing matters because it controls how aggressive your landing-site selection should be. "Immediately" means accept risk on the ground side of the trade. "As soon as practical" gives you margin to choose a friendlier site.