A series of tests was conducted to determine the effect that concentrations of hydrogen below its lower flammability limit can have on the burning of other materials. The vertical Bunsen burner test cabinet was set up to run tests with hydrogen concentrations varying between 0% and 4% by volume. Three different materials were tested: a 1/16″ thick woven carbon fiber, a fabric aircraft seat cover, and an 8-ply unidirectional carbon fiber. All three materials showed significantly increased after-flame times and burn lengths as the concentration of hydrogen increased. The burn rate of both carbon-fiber materials also significantly increased with increased hydrogen concentrations, whereas the burn rate of the seat-cover fabric remained relatively constant for all concentrations.
This report summarizes the research effort undertaken by the FAA to determine any differences in occupant survivability during a simulated post-crash fire when using thermoplastic paneling located in the lower seating area that meets current heat release rate requirements versus paneling that does not meet the current heat release rate requirements. The heat release requirement is based on the Ohio State University (OSU) Rate of Heat Release Test Method.
Two full-scale tests were conducted in the Full-Scale Fire Test Facility at the FAA’s William J. Hughes Technical Center in Atlantic City, New Jersey. The full-scale tests were conducted with a large external fuel fire adjacent to a B-707 narrow-body aircraft fuselage, which simulated a severe but survivable accident in which the fire entered the cabin through a simulated fuselage rupture. The fuselage was instrumented with thermocouples, gas-sampling lines, heat flux transducers, and smoke meters to monitor conditions during the test. The fuselage was also outfitted with flat honeycomb panels installed as sidewalls, stowage bins, and ceiling, and four simulated triple seats constructed of steel angle.
The upper section of the seats contained fire-hardened seat-cushion bottoms and backs that met current FAA flammability requirements, and the lower area contained thermoplastic sheet material on the aft and side areas. During the initial test, thermoplastic paneling that met the current FAA heat release requirements was used, whereas, during a second test, the thermoplastic paneling did not meet current requirements. The tests determined that the use of the noncompliant paneling resulted in more hazardous conditions late in the test.
These conditions were determined using a fractional effective dose model, using temperature and gas data collected during the tests.
This study has been carried out at the request of the Federal Aviation Administration (FAA) and the United Kingdom Civil Aviation Authority (UK CAA) under the provisions of a UK CAA contract. The broad objectives of the study are to collect and analyze data relating to in-service occurrences involving fire, smoke or fumes on US registered aircraft. This involved the compilation of data into a Fire, Smoke or Fumes Occurrence (FSF) Database compiled in Microsoft Excel. The analysis compares genuine and false occurrences by source of fire, smoke, fumes or odors and consequences (diversions, overweight landings, etc.). The data has also been analyzed to derive any likely trends in rates of occurrence. These objectives have now been achieved for data collected over the period 2002 to 2011 and are addressed in this report. A further objective of the study is to analyze the data to determine the monetary impact of the occurrences and any trends in these impacts, which is also addressed in this report.