Owners of aircraft powered by Gipsy Major engines are being contacted by the CAA after episodes of rough running engines and engine failures.
Analysis by the CAA shows an emerging trend of problems with the Gipsy Major engines. The use of 100LL Avgas fuel in these engines could be causing reliability problems particularly with cylinder heads, valves and valve seats.
Tiger Moths, Chipmunks and Austers are amongst the aircraft fitted with Gipsy Major engines. Photo (top) of a dh82 Tiger Moth by Tony Hisgett.
Owners of affected aircraft are advised by the CAA to ensure routine checks on these engines are carried out by a maintenance organisation or person experienced on the engine type.
Checks should also be carried out if incidents of low compression are noticed in the engine when turning the propeller by hand, or if the engine is found to be running rough.
Owners are also advised to ensure they are using the most appropriate fuel at all times – UL91 is the most appropriate, says the CAA.
As well as contacting all owners of affected aircraft types listed on the national aircraft register, the CAA is also issuing guidance material to continuing airworthiness maintenance organisations.