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 abouve a definite pre-established level. Type III: Flame - Contact, an instrument which will actuate an alarm signal when exposed to physical contact with flame.