An Emergency Airworthiness Directive (AD) has been issued for Rotax 915/915 engines by the European Aviation Safety Agency (EASA) and the UK CAA.
The AD follows a Service Bulletin issued by Rotax and concerns a deviation in the manufacturing process of an exhaust valve.
A broken exhaust valve has been reported on a non-certified Rotax 914 UL2-01 engine. Subsequent investigation identified deviation in the manufacturing process of the affected exhaust valve.
“This condition, if not corrected, could lead to in-flight shut down, possibly resulting in a forced landing with consequent damage to the aeroplane and injury to occupants.,” says EASA.
Due to similarity of design, this condition may affect also Rotax 915 iSc3 A, 915 iSc3 B engines and Rotax 914 F2, 914 F3 and 914 F4 engines. The AD requires replacement of affected exhaust valves.
The AD can be found here.