No 698/gov. from 31.05.02
to No . from
On the possibility of operation of M-14P engines after they had propeller impact against ground or other obstacle
At aircraft propeller impact against ground or other obstacles parts of gear box (propeller shaft, satellites, gears, propeller shaft bearing), crankshaft, gas distribution mechanism and supercharger drives receive sufficient non-evaluated shock loads. This makes impossible to evaluate their influence on engine workability in further operation without inspection.
Parts and units been overloaded (supercharger casing and parts, unit drives, gas distributor parts, connecting rods, parts of cylinder group) may be further used on condition that special inspection is carried out, which guarantees revealing the hidden defects, caused by overloading.
Engine cylinders, gearbox casing, rear cover, accessories, etc. may be used without special inspection, just according to conventional inspection procedure during overhaul.
According to the above stated, we consider that engine operation after propeller impact against ground or other obstacles is impermissible, as it may impinge flight security.
Such engines should be directed to OJSC OKB Motorostroyeniya or certified overhaul organizations to evaluate their technical condition and make decision on overhaul possibility and acceptance for further operation.
Vice-designer general [signature] V.D.Sherstiukov
Termikas Co Ltd