Tjor I. Eklund, Joeph A. Wright

The purpose of this test program is to devise and evaluate techniques for modeling aircraft cabin fires. A rotatable model fuselage section, 3 feet in diameter and 10 feet long, was placed adjacent to a height-adjustable 4-foot square pan of JP-4 for fire tests in a quiescent indoor environment. One door on the fuselage side was opened and exposed to the pool fire, while another door in the end of the fuselage remained either opened or closed during the fire test to create natural ventilation effects in the interior. Rotation of the fuselage and raising or lowering the fuel pan provided variations in the resultant interior hazard and led to the following four conclusions: (1) the opening of an additional door always decreases the measured hazard from an external pool fire covering an open doorway in a windless environment; (2) for the specific rotational positions tested on the model, the hazard to the interior form the external fire is increased as the fire base is lowered on the side of the fuselage; (3) when the fuel fire base is maintained at a fixed height with respect to the fuselage, the hazard peaks at the position where actual doorways are installed; (4) noted discrepancies among past tests with a variety of fuselages can be explained by accounting for differences in door location on the fuselage perimeter and height of the fuel bed.

Thor I. Eklund, Joseph A. Wright, Franklin D. Fran, Joseph F. Berenotto

The effort described herein was a quick-reaction evaluation of the performance of advanced aircraft windows in a model fire environment. The purpose was to provide a timely response to a request by Dr. John Parker, Chief of the Chemical Research Projects Office at AMES Research Center. Under this request, advanced epoxy/polycarbonate windows provided by the National Aeronautics and Space Administration (NASA) would be tested in the National Aviation Facilities Experimental Centers’ (NAFEC) quarter-scale model of the C-133 aircraft fuselage. An additional purpose was to provide some preliminary information to be used in planning a broader project on aircraft windows in fiscal year 1981.

George B. Geyer, Lawrence M. Neri, Charles H. Urban

The objective of this effort was to establish the feasibility of replacing a potentially lethal aircraft cabin environment with a cool habitable atmosphere which is nonsupportive of combustion during passenger evacuation in fire emergencies. For this purpose, carbon tetrafluoride (CF4) was chosen as the fire extinguishant because of its very low toxicity and high molecular stability under thermal insult.

Four large-scale experiments were performed in the completely instrumented cabin of a DC7 aircraft employing both Class A and B combustable materials. Three experiments were performed using the habitable inert atmosphere (27-volume percent CF4) discharging at the rate of 3,300 cubic feet per minute into the aircraft cabin through,a window exit. For comparative purposes, the fourth experiment was performed using neat CF4 discharged from two simulated points of fuselage penetration by a ballistically-powered aircraft skin penetrator nozzle. Both of these prototype fire extinguishing systems were designed to be employed by airport crash-fire-rescue services to extinguish aircraft cabin and compartment fires.

The CF4-air atmosphere was capable of extinguishing no survivable Class A and B cabin fires within 125 seconds or less during which time the cabin temperature was rapidly reduced and visual acuity slowly improved by smoke dilution during the Class A fire tests. Fire extinguishment by means of neat CF4 at the same discharge rate required approximately twice as long, and visibility within the cabin did not improve during the duration of the experiment.

G.B. Geyer

The principle objective of this investigation is to determine the fire extinguishing effectiveness of a fixed onboard, dry-pipe foam/water sprinkler system in terms of the solution discharge rate and application density, required to control and extinguish full-scale cabin fires involving seats, carpets, and the side/ceiling panels. Means will be developed for coupling the onboard foam/water sprinkler system to an adjacent crash-fire-rescue {CFR} foam truck through a permanent. fixture mounted in the aircraft fuselage. Additionally, methods will be devised to utilize the potable onboard water supply in the system pending the arrival of the CFR services.

Richard G. Hill, George R. Johnson, Constantine P. Sarkos

This report describes results obtained utilizing a full-scale, wide-body test article for studying postcrash cabin fire hazards produced by an external fuel fire adjacent to a cabin door opening. Seventy-two tests were conducted at various ambient wind conditions and fire sizes in a fire-hardened cabin devoid of interior materials. This work was the first phase of a study to realistically characterize postcrash cabin f ire hazards. Temporal data, taken at a large number of cabfn locat ions, are presented and discussed pertaining to the effect of ambient wind on the rate of hazard accumulation inside of the cabin; stratification of heat, smoke, and toxic gases; the effect of fire size of thermal radiation through the opening; and the relative importance of heat, smoke, and carbon monoxide in a fuel-dominant fire. It is concluded that major stratification of hazards occurs in, the cabin when the hazards are created by an external fuel fire, and that ambient wind determines the amount of hazards entering a cabin due to a given external fuel fire.