Carbon Monoxide in Piston Engine Aircraft

We asked for feedback from the General Aviation (GA) community on the challenges facing pilots in obtaining an active carbon monoxide (CO) detector, the importance of protecting passengers from CO, the role that maintenance plays in combatting CO, and whether active CO detectors ought to be mandatory for some operations.

CAP 2975 was published in February 2024 and was consulted on over a four-week period. The consultation included nine specific technical questions as well as an opportunity for respondents to provide free-text comments.

We received a total of 271 separate responses to the consultation. The Comment Response Document (CAP 3024) provides a summary of the responses received and the decisions taken as a result.

Based on the findings from this consultation and the extensive work done in this area over the last four years, the CAA will be issuing a directive requiring an active CO detector to be present in specified piston engine aircraft operations. The requirement will follow closely the proposal set out in CAP 2975, but will be modified to take into account the comments received in the consultation.

The CAA will not, at this time, introduce mandatory CO concentration checks in piston engine aircraft maintenance programmes beyond what is already specified by aircraft manufacturers and UK Reg (EU) No.1321/2014 Annex Vb (Part-ML), Minimum Inspection Programme (MIP).

The CAA will publish additional guidance on selecting an appropriate active CO detector, where and how to securely position devices in aircraft, how to respond to alerts, as well as guidance on exposure levels and thresholds for alarms.