Lawrence J. Curran, Jr.

This report evaluates fire test methodologies for aircraft flight data and cockpit voice recorders. The current fire test requirements consists of a 30 minute exposure to a propane burner calibrated to the heating conditions created by a jet fuel fire. A comparison was made of the internal temperature of flight recorder models subjected to the propane burner standard and a jet fuel fire. The internal temperature was approximately 40 percent higher during the fuel fire tests which were 6-8 minutes in duration. Although the fuel fire duration was limited, it appears that a 60-minute propane burner test exposure is a feasible and conservative means of evaluating the thermal resistance of a flight recorder subjected to a 30-minute fuel fire. An additional fire test condition (500 F/10 hours) has been proposed to simulate a smoldering fire which may persist for a long period of time at remote site. A state-of-the-art magnetic tape of the cockpit voice recorder was subjected to this condition in an oven and failed the test, demonstrating the severity of this exposure environment.

Richard M. Johnson

A comparison was made between data produced by Heat Release Apparatus complient with present FAA/JAA standards and data produced by Heat Release Apparatus designed and used by the All-Russian Institute of Aviation Materials (VIAM). Results show little or no correlation between the two.

National Transportation Safety Board

Volume I contains the Safety Board's responses to a number of recommendations made by the aviation industry during the Safety Board's Aviation Accident Investigation Symposium held at Tyson's Corner, Virginia, from March 29 through 31, 1994. Volume II contains presentations made by symposium participants. The symposium provided a forum for the aviation industry to discuss and critique Safety Board programs and practices, as well as procedures used during aviation accident investigations. Participants included representative from U>S. air carriers, airframe and engine manufacturers, aviation associations and unions, government officials and interested parties, as well as foreign investigative and manufacturers.

Keith E. Crouch

The Navy and the Air Force recognized the need for improved test procedures for evaluating the lightning protection design of aircraft fuel systems. Under their sponsorship, a program to develop adjustable, standard ignition sources which could be used to calibrate techniques for detecting ignition sources during lightning testing was established. The minimum ignition levels of voltage sparks and hot spots were established under the program before it was terminated due to funding problems.

The present program, under FAA sponsorship, is a continuation of the original program. The Standard Voltage Spark Ignition Source and the Standard Hot Spot Ignition Source were completed and documented. The most promising approach for developing a Standard Thermal Spark Ignition Source was determined and is presented.

.Photographic detection techniques were investigated and the limitations determined. The presence of light on a photographic film indicated the possibility of an ignition source but can not confirm the ignition probability (if any).

Hydrogen mixtures appear to provide the ability to have adjustable ignition probabilities and low energy (low over-pressure) ignitions.

Richard M. Johnson

A series of 150 comparative tests were run by four currently operating laboratories using heat release apparatuses compliant with present FAA/JAR standards and the ATI-Russian Institute of Aviation Materials (VIAM) designed heat release apparatus. The evaluation of data showed little or no correlation between the subject apparatus and the four compliant apparatuses.