G. R. Slusher, J. Wright, J. E. Demaree, & W. E. Neeses

Hand-held Halon 1211 fire extinguisher were evaluated in a four-place Cessna Model 210C aircraft. The aircraft was operated in an airflow facility under simulated flight conditions. Extinguishers of 2.5 pound capacity were discharged to determine the dissipation rate and toxicity levels of Halon 1211 extinguishing agents.

Agent concentration dissipated rapidly. Analysis of dose calculations demonstrated that 2.5 pound Halon 1211 extinguishers were safe in the four-passenger test aircraft. Dose calculations for the pilot were only 25 percent of the limit for Halon 1211. Ventilation airflow produced air changes in the cabin of 1.16 minutes at 120 miles per hour airspeed and 1 minute at 140 miles per hour. The high cabin ventilation rates together with the effects of agent stratification resulted in safe conditions. The effective air change time found in analysis was of the order of one-third of a minute. This quantity used in the procedures outlined in Advisory Circular AC-20-42B leads to the conclusion that discharge of Halon 1211 weights of 6 pounds can be safely withstood in the C120 under flight conditions.

Discharge of a 2.5 pound chemical powder extinguisher adversely affected visibility for over 22 seconds.

Richard Johnson

This study provides for an identification of accident scenario(s) and associated occupant risks and survival equipment needs, relating to the inadvertent or unplanned water contact of transport category airplanes. This identification was obtained. In part, from the results of contractual studies of transport accident data. The subject study concludes that while the unplanned water contact of a transport airplane occurs less frequent than corresponding ground contact, the impact loads are often higher, leading to greater fuselage damage. Also, the unplanned water contact occurs more frequent than a planned water landing (ditching) and usually involves adverse flooding conditions. These conditions, in turn, affect the ability of occupants to retrieve, deploy, and/or don on-board floatation equipment.

US Department of Transportation

The objective of this project is to develop improved fire protection measures for transport aircraft lavatories.

R. Filipczak

The Ohio State University (OSU) Rate of Heat Release Calorimeter has been modified to measure selected toxic gases in the combustion products from an aircraft material test specimen. Through application of simple fire and survival models, an index for rating the fire hazard of a material tested in the OSU Calorimeter has been proposed pased on the heat and toxic gases measurements taken (Combined Hazard Index, or CHI). This technical note presents the theory and documents the software used to calculate a CHI using OSU Calorimeter data.

Louis J. Brown, Jr. Charles R. Cole

The Federal Aviation Administration Standard 2-gallon/hour burner was adapted to measure the burn-through resistance of aircraft cargo compartent lining materials. Thislaboratory test can subject lining samples to the fire conditions found in full-scale class D cargo compartment tests. A 5-minute test period is of adequate duration to evaluate the performance of cargo lining materials, bsed on full-scale test results which showed that class D fire intensity is reduced to a smoldering state after several minutes. It ws determined that the 2/gallon/hour burner test is superior to vertical and 45 degree bunsen tests specified in Federal Air Regulations (FAR's) 25.853 and 25.855 for evaluating the flammability and burn-through resistance of cargo compartment lining materials. The following criteria for Class D cargo compartment lining materials using 2-gallon/hour burner test are proposed: Sample must prevent burn-through for 5 minutes, and peak temperatures at 4 inches above the upper surface of a horizontal test sample should not exceed 400 degree Fahrenheit. Based on results with this laboratory test, it is concluded that fiberglass lining materials provide sufficient protection to prevent burn-through in a class D cargo compartment fire, Nomex and Kevlar lining materials will not contain a class D compartment fire.