RGW Cherry and Associates

The objective of this analysis was to assess the number of Serious Injuries and Fatalities that might be avoided from the use of ’16g dynamic seats configured without enhancements to head injury criteria’ and to compare this with the assessed benefit from ’fully compliant dynamic seats’.

John W. Reinhardt

This technical note provides the technical approach and test results of the evaluation of the currently used Federal Aviation Administration certification test, known as the 12-second vertical Bunsen burner test, to certify aircraft ducts and conduits.

Stanislav I. Stoliarov, Phillip R. Westmoreland, Huiqing Zhang, Richard E. Lyon, and Marc R. Nyuden

The applications presented here demonstrate the potential for using quantum chemical methods and molecular simulations to determine the mechanisms and rates of the thermal decomposition of polymers. The expectation is that these capabilities can be used to predict the flammability of materials and develop strategies to improve fire resistance. The thermal decompositions of poly(dihydroxybiphenylisophthalamide) and bisphenol C polycarbonate are investigated by performing density-functional calculations of potential energy surfaces of model compounds representing the polymers. Reactive molecular dynamics, a relatively new technique that extends conventional molecular dynamics to modeling chemical reactions, was used to simulate the thermal decomposition of polyisobutylene. The advantages and limitations of both computational approaches are discussed.

William M. Cavage

Recent Federal Aviation Administration research has illustrated that fuel tank inerting could be practical in the commercial fleet for the protection of center wing or body style tanks. The effect of pressure differences on the release of dissolved oxygen in a fuel load on an inert fuel tank ullage was studied. A test article was constructed and experiments were conducted to quantify the potential increase in oxygen concentration in an adjacent inert ullage as a result of gases in fuel during sea level stimulation, as well as at reduced atmospheric pressure. Different methods of stimulating the release of gases from the fuel were examined during laboratory experiments in an attempt to quantify the increase in oxygen concentration in an inert aircraft fuel tank ullage. This data was compared with flight test data in an attempt to gage the ability of laboratory tests and simple calculations to predict the resulting change in oxygen concentration of an inert commercial airplane fuel tank during a flight cycle.

The oxygen evolution from different fuel loads was measured to determine the resulting oxygen concentration on an adjacent ullage. At sea level, the increase in oxygen concentration can be as great as 7 percent for an ullage inerted to 6 percent with an 80 percent fuel load that was stimulated. Increasing altitude allows for an additional increase in the oxygen concentration of the ullage even if the ullage was at equilibrium at sea level. Inerting the ullage through fuel has the effect of scrubbing the fuel to some rudimentary level of protection that reduces or eliminates the increase in oxygen concentration due to fuel air evolution, depending upon fuel load. Flight test data illustrated a relatively small amount of oxygen evolving from fuel compared to the theoretical amount available. Any effect of oxygen concentration increase due to fuel tended to be obscured by the more dominant effect of air entering the vent due to fuel consumption. Oxygen concentration flight test data with consumed fuel loads and inert ullages were best duplicated in laboratory experiments by not stimulating the fuel. Calculations of oxygen concentration increase have poor agreement with flight test data, but the flight test oxygen concentrations results fall within the band of 0 and 100 percent oxygen evolution.

John W. Reinhardt

This technical note presents the second update to the minimum performance standards that a Halon 1301 replacement or alternate system for aircraft cargo compartment must meet as part of the aircraft certification procedures. This document replaces report number DOT/FAA/AR-TN03/6. This standard considers gaseous and nongaseous fire suppression systems for full-scale fire testing. This report update includes the corrections made to the aerosol can simulator specifications, acceptance criteria section, and the new criteria for the aerosol can explosion test. In addition, some sections were added to the test requirements to clarify some testing procedures.