FAA AC 33.4-2:2001
FAA AC 33.4-2:2001 Instructions For Continued Airworthiness: In-service Inspection Of Safety Critical Turbine Engine Parts At Piece-part Opportunity Gives guidance and acceptable methods, but not the only methods, that may be used to demonstrate compliance with the requirements of section 33.4 of Title 14 of the Code of Federal Regulations, Instru