The high value of military aircraft means strict operational procedures during maintenance and testing. However, there is a still fire risk. A malfunction or damage to the aircraft can cause a fuel, or hydraulic fluid leak, that can be ignited by hot surfaces or electric sparks. The fire protection system in an aircraft hangar is must, so as to extinguish or suppress flammable liquid fires on or underneath an aircraft with minimal damage to the plane. In addition the system should prevent the fire from spreading too, or damaging, adjacent aircrafts or equipments.