Carbon Monoxide in Piston Engine Aircraft

In February 2024 the UK Civil Aviation Authority (CAA) launched a 4-week public consultation on carbon monoxide (CO) in piston engine aircraft, seeking stakeholder views on the barriers facing pilots in obtaining an active CO detector, the role that maintenance plays in combatting CO, the importance of protecting passengers from CO, and whether active CO detectors ought to be mandatory for some operations.

The CAA has now published the Comment Response Document for this consultation, which includes a summary of the responses received, the decisions made, as well as the next steps being taken.

The CAA will be issuing a Safety Directive requiring an active CO detector to be present in specified piston engine aircraft when operating with passengers on board who do not possess a recognised pilot qualification. The directive will be published later this month and will come into effect from 1 January 2025.

These are the three decisions that the CAA have made:

CAA Decision 1

The CAA will introduce a requirement to have a functioning active carbon monoxide detector, capable of alerting via aural and/or visual means, in specified piston engine aircraft when operating with passengers on board who do not possess a recognised pilot
qualification. The comments provided in this consultation will be taken into account when developing the requirement.

CAA Decision 2

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).

CAA Decision 3

The CAA will publish additional guidance on topics including: 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.