Miles M-65 Gemini 1A, G-AKKH
Whilst flying close to Old Warden airfield, the left propeller detached in flight and the aircraft was subsequently landed without further incident. The tightness of the bolts retaining the wooden propeller had last been checked at the annual check, 24 flying hours previously. Of the two bolts recovered, both showed indications of fatigue failure and the propeller boss had evidence of movement relative to the hub. The investigation has revealed that the general application of the basic LAMS schedule to historic aircraft may leave some of their less usual features inappropriately maintained. Although in this particular case the maintenance involved was restricted to the propeller attachment, there may be several areas in which the methods of construction and materials may require more frequent maintenance than is usual with more modern constructions. As was seen in the original Gemini Service Manual, several items were scheduled for 10 hour, 20 hour and 40 hour maintenance intervals and it is most probably amongst these, and any items which may be seasonally affected, that requirements different from those of the basic LAMS may occur. It is therefore recommended that:- Recommendation 2004-104:- The Civil Aviation Authority should, when approving the application of the Light Aircraft Maintenance Schedule to historic aircraft, review the appropriateness of the resulting inspection intervals against those of the original Maintenance Schedule, if is available, and require out of phase maintenance actions where appropriate.
G-AKKH.pdf (150.58 kb)