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.
Idler pulleys are engine pulleys that are responsible for guiding and tensioning the engine drive belts. The engine drive belts are routed in a specific manner around the various engine accessories, such as the alternator, water pump, power steering pump, and AC compressor.