US Patent 9988160 Airplane fire detection system

A fire detection system includes a heat detector controller and a multiplicity of heat detectors. The heat detectors are positioned at predetermined locations along a ceiling of a cargo compartment and/or on an exterior side of a cargo compartment liner from an interior of the cargo compartment. Each of the multiplicity of heat detectors are configured to measure temperature and to transmit temperature measurements to the heat detector controller. The heat detector controller is configured to determine that a fire has breached the cargo compartment liner based on the temperature measurements.