This Aeronautical Standard covers the following basic types of fire detection instruments@ or combinations thereof@ intended for use in protecting aircraft powerplant installation@ auxiliary powerplants@ combustion heaters and other installations where fuel@ oil or similar fires may occur. Basic Types: Definition of Type I Thermal - Fixed Temperature@ an instrument which will actuate an alarm signal when exposed to any temperature above a definite pre-established level. Type II Thermal - Rate of Rise@ an instrument which will actuate an alarm signal when exposed to any rate of temperature change above a definite pre-established level. Type III Flame - Contact@ an instrument which will actuate an alarm signal when exposed to physical contact with flame.