CIR Aviation Abbreviation

Circuit

An electrical arrangement requiring a source of voltage, a closed loop of wiring, an electric load and some means for opening and closing it. Or Optimum fire rating issued by Underwriter's Laboratories on roofing. The building codes in some areas require this type of roofing for fire safety. or The path of electrical flow from a power source through an outlet and back to ground.

Cockpit Image Recorders

Conformity Inspection Record (FAA 8100-1) 

All inspections conducted by an ASI or designee to determine conformity to an approved type design before an airworthiness certificate is issued must be recorded on FAA Form 8100-1.