Electrical Fire

An electrical fire results from short circuit, overload, or defective insulation. The first sign is usually a burning smell before visible flames.

Source: POH (binding), FAA-H-8083-3B Chapter 17.

Symptoms

Burning smell (insulation, plastic).
Smoke in the cockpit, often from the instrument panel.
Crackling or sparks.
Failure of individual avionics/instrument functions.
Ammeter shows very high current or negative.

Standard procedure (POH-specific)

Master switch OFF — disconnects all electric circuits → fire starves of power.
Avionics master OFF (if separate).
Cabin heat / vents OFF (prevents further smoke spread).
Have emergency extinguisher ready (halon or CO₂); water only as last resort (shock risk while system live).
Land ASAP — even if the fire is out, it may relight.
Mayday and squawk 7700 (radio still possible on battery).
Doors unlatched before touchdown.

Identifying the source

If the fire goes out after master OFF, cautiously reset individual circuits — if smell returns, leave that circuit off.

Ventilation

Open windows (slowly, no panic) to vent smoke.
Air-flush cabin through cabin air vents (if not the fire path).

Risk: cabin heat

Cabin heat in many light aircraft comes from the exhaust manifold (heat muff). If the manifold is leaky, CO (see next lesson) OR with severe damage even combustion gases can enter the cockpit. → at any suspicion, cabin heat OFF.

What not to do

No water on live electrical equipment (shock).
Do not hesitate with master OFF — modern avionics can take time to recover but that is acceptable.
Do not silence the radio before Mayday — other traffic can help.

Forced landing

With master OFF: altimeter (static) still works, airspeed indicator (pitot-static) works, magnetic compass works — basic instruments suffice for a forced landing.
Attitude indicator (vacuum) still works (vacuum pump is non-electric in most light aircraft).
GPS / radio lost → visual navigation.