Accident G-CICF

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.

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.

Further research has since taken place on thermal runaway, fire risk, least risk location and crashworthiness to ascertain the perceived event probability. Based on recent correspondence with the LAA and BMAA as of June 2026, advanced drafts of Technical Directives, Standard Minor Modification procedures, and associated Technical Leaflets are currently undergoing review by relevant subject matter experts. Subject to completion of this review, these documents will be issued by the LAA/BMAA imminently for consultation with A8-1/A8-21 organisations and relevant members.

Following the consultation period, final promulgation of all necessary documentation including service bulletins is currently planned to take place by the end of Q3 2026.

At the time of writing the expected compliance timescale for any directive issued by the LAA/BMAA is likely to be during 2027, but active discussions remain ongoing at this time.

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.

It is still the intention towards the conclusion of this process to remind organisations holding an A8-1/A8-21 approval of their obligation to disseminate safety information (such as service bulletins) issued by the aircraft manufacturer, ensuring that critical safety updates reach operators in a timely manner.

The CAA will provide a further update on the actions taken to address this Safety Recommendation by 31st October 2026.

Adequate - Open

31/10/2026