59-10-06 KAMAN: Applies to All K-240 Helicopters (Military HTK-1).
Due to associated adverse service experience, the wood type cheek plate rotor blades, P/N K411042-1, -2, -7, and -8 are ineligible for use. These blades modified to conform to, or replaced by, fiberglass type cheek plate rotor blades, P/N K411042-77 and -78, are acceptable with a 2,500-hour retirement life.