The UK’s Air Accident Investigation Branch has issued a report on what it describes as a “serious incident” involving an Ikarus C42 FB80 Bravo (G-CICF) after a lithium-ion main battery caught fire shortly after takeoff from Headcorn Aerodrome, Kent on 8 December 2022.

The two-seat high-wing microlight was originally equipped with a 12 V sealed lead-acid battery used for engine starting and power for the avionics, electric fuel pump, electric trim and aircraft lighting; the li-ion battery involved in the fire was a replacement.

According to the AAID, the fire created significant quantities of smoke and hazardous gases within the aircraft cabin that affected the ability of the pilot to safely control the aircraft. A passenger, sitting in the right seat, was able to open the cabin door in flight, which reduced the level of smoke in the cabin and the aircraft landed safely.

The investigation did not identify the cause of the battery fire. The location of the battery within the aircraft’s cabin exposed the occupants to significant hazards when the battery caught fire, as the battery box did not contain the combustion products or heat from the fire.

A similar airborne battery fire to the same aircraft type and lithium-ion battery type was found to have occurred in Germany, resulting in destruction of the aircraft.

One Safety Recommendation is made relating to reviewing the installation requirements of lithium-ion main batteries in cabin areas of Non-Part 21 aircraft, to minimise the effect to aircraft occupants following a battery fire.

The AAIB’s report can be downloaded here.
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