Advanced Fire Detection Systems

 
Aircraft Fire Detection
 
The luggage and cargo compartments under the floor are now required to be equipped with fire detectors and extinguishers. One of the major challenges of fire detection in cargo compartments is the minimization of false alarms. The current detectors being used in aircraft cargo bays use either photoelectric or ionization sensors to detect the smoke particles produced by a fire. While smoke detectors work well at detecting the presence of fire, they can be fooled by the presence of other particles, such as dust, fog and other aerosols that sometimes form in the cargo compartments. It has been estimated that as many as 200 false alarms occur for every actual fire. In-flight fires are relatively rare events. However, there are no provisions for the pilot or crew to verify the presence of a fire in the under-floor cargo compartment. Any alarm has to be treated as an actual fire, forcing the pilot and crew to follow emergency procedures, such as landing at the nearest airport, discharging extinguishing equipment, etc.

 
Makel Engineering in conjunction with NASA Glenn Research Center, Case Western Reserve University and Ohio State University have developed a fire detection system based on MEMS (Micro-Electro-Mechanical Systems) technology that combines particle detection with chemical sensing. The unique combination of sensing technologies enables effective detection of fires, while minimizing false alarms. This technology was recently demonstrated at the Federal Aviation Administration (FAA) Cargo Compartment Fire Testing Facility in Atlantic City, NJ. The fire detection system was exposed to standard fire tests and false alarm triggers, such as dust and fog, and compared to a conventional smoke detector used in cargo compartments. Both systems showed similar ability to detect actual fires. However, when exposed to dust and fog, our fire detection system did not alarm, while the conventional detector did.

 

 
Early Fire Detection for Space Applications
 
For Space Flight, there is a need to detect and identify potential hazards before they become a fire. For instance, when electrical wires overheat, the insulation starts to release trace amounts of chemical compounds well in advance of a fire. As there are many materials used in a spacecraft, there are many different characteristics associated with them, including the amount of smoke and the chemicals released when overheated. The combination of particle and multiple chemical species detection enables not only the early detection, but also the identification of the type of fires or fire precursors. This information, in turn, enables the crew to take appropriate measures to prevent and/or contain the fire hazard.