AIRCRAFT ENGINE NACELLE FIRE
There are scenarios where fires develop in very restricted spaces, for example, in aircraft engine nacelles or other confined mechanical equipment spaces where the potential for the simultaneous presence of both flammable fluids and an ignition source are highly probable. In such cases ESI has developed a suppressant unit, referred to as the Self-Contained Fire Protection System (SCFPS), capable of high-speed fire protection for standalone applications.
This unit has been extensively tested within a full scale rotorcraft engine nacelle fire simulator, Figure 1, in which a range of internal air flows, fuel flow rates, and fire locations as specified in an original Halon Replacement study was considered.
Although the SCFPS is a standalone unit without the need for electric power or a fire extinguishing agent under normal operating conditions, some modifications had to be considered while using this nacelle fire simulator. However, the modifications did not prevent or assist the operation of the SCFPS, with all testing utilizing low pressure compressed air for delivery of the suppressant agent.
Figure 1: Schematic of the Full Scale Engine Nacelle
Figure 2: Typical Detection (Red Circle) and Extinguishment of a Fire in Confined Space in an Engine Nacelle Simulator
Evaluation of the performance of the SCFPS over a range of flight conditions as specified by the engine manufacturer from Hover to well over 100 Kts was undertaken. The ESI SCFPS clearly demonstrated the ability to extinguish 100 % of the fires in less than 300 milliseconds, Figure 2, and utilized less than 5.7 gms (0.2 ounces) of suppressant agent in each test, as shown in Figure 3.
Figure 3: Typical Amount of Fire Suppressant Needed to Extinguish Fire in an Engine Nacelle Simulator