Steven M. Summer

While it is well established that the shipment of a large quantity of flameless ration heaters poses a significant fire safety risk, this report examines the potential hazard associated with the use of these flameless ration heaters in an aircraft cabin and with the accidental activation of them in a confined area aboard an aircraft, such as in overhead storage bins or a cargo compartment.

Tests were performed both with individual Meals, Ready-to-Eat containing flameless heaters in an open environment and multiple Meals, Ready-to-Eat in a confined space to examine their potential hazard. Temperatures in excess of 215°F and violent ignition events were observed. It is evident from the tests performed that the release of hydrogen gas from these flameless ration heaters is of a sufficient quantity to pose a potential hazard on board a passenger aircraft.

Dave Blake

This report documents the development and testing of a standardized fire source for cargo compartment fire detection systems. Note that currently, these fire sources cannot be used in actual certification flight tests. The intent of this work was to define a fire source in terms of heat release rate, mass loss rate, and smoke and gas species production rates, and then devise a safe method to simulate whichever aspect of the fire signature that the particular detection system was designed to respond to in the certification tests. This could be done singly or in some combination with smoke generators, heat guns, and the controlled release of actual or surrogate gas species. This report discusses how this fire source is used in a computational fluid dynamics model to predict the transport of smoke, gases, and heat throughout a cargo compartment. The testing concluded that the fire source used in a simulated smoldering fire mode does not produce a fire signature that would be useful in developing multicriteria fire detectors with a better capability to resist false alarms. This report also documents the amount of smoke that would be detectable in various size cargo compartments and the resultant responses of currently in-use aircraft smoke detectors from the simulated smoldering and flaming fires.

Richard E. Lyon, Louise Speitel, Robert Filipczak, Richard Walters, Sean Crowley, Stanislav Stoliarov, Lauren Castelli, and Michael Ramirez

The chemistry and properties of polymers containing the fire-smart moiety 1,1-dichloro-2,2-diphenylethene (DDE) are described. These polymers are typically derived from the bisphenol of chloral and are low-cost, easily processed, and have good mechanical properties and toughness under normal conditions. Under fire conditions, the DDE group undergoes an intramolecular rearrangement to diphenylethynyl with the elimination of hydrogen chloride (a noncombustible gas) and intermolecular cross-linking to form an aromatic char residue in high yield. The flammability and mechanical properties of DDE-containing polymers are described.

Patricia Cahill, Timothy Marker, & John Reinhardt

Intermediate-scale flammability testing of Hypalon™ RB71, a thermal acoustical insulation primarily used to insulate ducts, was conducted in a section of a wide-body aircraft. The aircraft section was configured to represent the attic area of a transport category aircraft. Baseline tests were also conducted using metallized Tedlar™ film cover over fiberglass to wrap the ducts. Temperature versus time and the relative energy release rate versus time were evaluated and are presented in this report.

Paul M. Hergenrother, Craig M. Thompson, Joseph G. Smith Jr., John W. Connell, Jeffrey A. Hinkley, Richard E. Lyon, and Richard Moulton

As part of a program to develop fire-resistant exterior composite structures for future subsonic commercial and general aviation aircraft, flame-retardant epoxy resins are under investigation. Epoxies and their curing agents (aromatic diamines) containing phosphorus were synthesized and used to prepare epoxy formulations. Phosphorus was incorporated within the backbone of the epoxy resin and not used as an additive. The resulting cured neat epoxy formulations were characterized by thermogravimetric analysis, propane torch test, elemental analysis, microscale combustion calorimetry, and fire calorimetry. Several formulations showed excellent flame retardation with phosphorous contents as low as 1.5% by weight. The fracture toughness and compressive strength of several cured formulations showed no detrimental effect due to phosphorus content. The chemistry and properties of these new epoxy formulations are discussed.