AAIB Report: Ikarus C42 FB80 Bravo, G-CICF, on 8 December 2022
Safety Recommendation: 2024-006
Safety Recommendation Text
It is recommended that the Civil Aviation Authority amends the design and installation requirements for lithium-ion main batteries that are located in the cabin areas of Non-Part 21 aircraft, to minimise the hazard to aircraft occupants following a thermal runaway.
CAA latest update
The CAA have been continuing to work with the Light Aircraft Association (LAA) and British Microlight Aircraft Association (BMAA) to review and, where necessary, amend their existing standard modifications for fitment of lithium main batteries in place of standard lead-acid batteries to ensure the installations comply with the relevant design and installation requirements.
Work continues to focus on revising and updating Standard Minor Modification procedures and associated technical leaflets. These are now anticipated to be completed by the end of April 2026.
Additionally, further research on thermal runaway, fire risk, least risk location and crashworthiness is being performed and correlated with the perceived event probability. Once the research has been concluded, revisions to modification procedures will be finalised and Mandatory Directives drafted and consulted on with a view to publishing by the end of May 2026.
It is worth re-iterating that considering the above proposals are focusing on evolving modification procedures, there is no current intention to amend initial airworthiness requirements for lithium-ion batteries.
Plans are also still in place to remind organisations holding an A8-1 approval of their responsibility to promulgate safety information (e.g. service bulletins) issued by the aircraft manufacturer to ensure that critical safety information is provided to operators in a timely manner.
Next update due
June 2026