Current testing requirements for high temperature alloys are defined in general industry specifications (ASTM, AMS), as well as in user specifications. Many of these requirements were established in the 1960's when production practices were yet to be refined.
cowling - protective covering consisting of a metal part that covers the engine; there are powerful engines under the hoods of new cars; the mechanic removed the cowling in order to repair the plane's engine.
Place the cowl back onto the engine and insert the mounting bolts. Tighten the cowl bolts with a socket and wrench. Pull the rope to start the engine. Remove the two screws on the screen with a screwdriver or small socket to access a defective ratchet spinner. Pull the spinner cap off.