EGG HARBOR TWP., N.J. — Two fire safety researchers at the FAA's William J. Hughes Technical Center recently received a U.S. patent for an invention that will provide earlier detection of fires in aircraft cargo holds.
Dave Blake and Richard Lyon, of the FAA's Fire Safety Branch, developed a test that can simulate two types of fires that might develop in the cargo hold – a smoldering (early-stage) fire and a flaming (late-stage) fire.
The two also developed a combustion test sample for testing cargo compartment fire/smoke detectors. This test sample generates heat, smoke and gases – the same mixture of combustion products that would typify a cargo compartment fire under flaming or smoldering conditions.
"Dave Blake and Richard Lyon have demonstrated their skills and expertise by creating this tool and securing this patent," said Pat Lewis, FAA program director, Airport and Aircraft Safety Research & Development Division. "Their efforts will enhance the safety of aircraft cargo compartments, and will provide long-term benefits to aviation safety, overall."
Fires in aircraft cargo holds are difficult to detect before they reach the stage where they endanger the aircraft. The fires can begin very slowly, generating gases with little or no flames, heat or visible smoke. Most current cargo fire detectors are optical systems. They detect smoke, but by the time smoke is generated, the fire has advanced, and the threat to the aircraft is greater. To improve detection, sensitivity levels are turned up on the detectors, but this results in frequent false alarms – about 200 false alarms for every real fire detected. A reliable detector for this early stage of fire development would provide valuable time and opportunity for the crew to make a safe landing.
This combustion sample should simplify the development of new cargo compartment fire/smoke detectors with multiple sensors that can detect early-stage fires, and can discriminate between real fires and nuisance alarm sources, enhancing safety for air travelers.
To create the sample, the researchers combined a mixture of pellets of the plastics usually found in cargo compartments. They molded the pellets into small samples, with a heating element embedded in the center. When the heating element is energized, the pellets begin to smolder, generating the gases of an early-stage cargo fire. Increasing the power or adding a flammable liquid to the mix creates a late-stage flaming fire atmosphere.
Richard Lyon is a polymer engineer and the FAA program manager for fire research. He develops new polymers, material models for fire response and improved test methods and analyses for assessing fire hazards. Lyon holds several patents and has published more than 50 journal articles and book chapters on the physics, chemistry, mechanics and flammability of polymers and their composites. He holds masters' and doctoral degrees in polymer science engineering, and a bachelor's degree in chemical oceanography, all from the University of Massachusetts, Amherst. He is a former materials research engineer at the University of California's Lawrence Livermore National Laboratory.
Dave Blake is an aerospace engineer who conducts full-scale and lab-scale fire safety research projects, covering a broad variety of aircraft fire scenarios and materials. He has participated in the on-site investigations of more than 35 aircraft accidents that involved fire, worldwide. His focus is developing certification guidelines for cargo compartment fire detection systems. Blake holds a master's degree in aviation management from Embry Riddle Aeronautical University, and a bachelor's degree in mechanical engineering from Drexel University.