At Least One Aircraft Has Experienced An In-Flight Carbon Monoxide Alarm Event

We're becoming big fans of the work we've seen conducted by the UK's Light Aircraft Association... which has just issued a Mandatory Technical Directive... 

The MTD, MTD-03-2024 has been issued to introduce mandatory disabling of cabin heat on examples of the type fitted with Rotax 914 (and derivative) engines. This follows an in-service occurrence of carbon monoxide entering the cabin due to leaks from the exhaust system. The Directive applies to operators of the Aeropro Eurofox, more specifically all models fitted with Rotax 914 engines (or derivatives) and cabin heat.  

The Directive was instigated by an example of the type fitted with a Rotax 914-UL engine that experienced an in-flight carbon monoxide alarm event. Upon further investigation, it was found that the intake for the cabin heat was located downstream of a joint in the exhaust system which had started leaking, contaminating the cabin with carbon monoxide. 

Operators are being told to secure the cabin heat selector valve in the closed (off) position, and to then mark the cabin heat selector valve operating lever as ‘inop’. 

The MTD must have been carried out before flight on or after 5th June 2024. This MTD has reportedly been emailed to all affected owners. 

An LAA inspector must check that the above actions have been satisfactorily completed and record in the airframe logbook that this MTD has been complied with.

FMI: www.lightaircraftassociation.co.uk/infolibrary/4d821c0a-89a3-45f5-98d3-53e60b856f08