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
We 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.
The most recent trilateral meeting between the CAA/LAA/BMAA was held in September 2025.
From this recent meeting, it has been agreed that respective procedures surrounding standard modifications for LAA/BMAA aircraft require updating to ensure only batteries that meet the relevant Technical Standards Order (such as those meeting DO-311A standards) are to be located aft of the firewall. These procedural updates are anticipated during the first quarter of 2026 and will be customised as required to the respective LAA/BMAA fleets.
It has also been considered that where necessary, alternative means of compliance giving an equivalent level of safety would be considered via the normal modification processes for each respective organisation.
Additionally, mandatory technical directives and mandatory permit directives are being considered as a potential course of action. This would mandate the removal of any LiFePO4 batteries aft of the firewall unless of a type meeting the relevant Technical Standards Order (or otherwise approved by the CAA/LAA/BMAA). A sufficient timeframe for compliance is currently being considered by the CAA/LAA/BMAA.
Considering the above proposals focusing on evolving modification procedures, there is no current intention to amend initial airworthiness requirements for lithium ion batteries. There are however plans 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
March 2026