A.M. Cobbett

Evidence from aircraft accidents indicates that cabin crew can have a positive impact on passengers’ ability to effectively evacuate an aircraft. A program of 24 competitive evacuations were performed in an attempt to determine the effect of cabin crew behavior upon rate of egress from a stationary aircraft simulator. Three cabin crew behaviors were assessed, two assertive cabin crew, two non-assertive cabin crew and no cabin crew. The evacuations were conducted on board a Boeing 737 cabin simulator.

A totals of 651 volunteers (64.4% male) with a mean age of thirty years participated. All volunteers received a f10 attendance payment. The first 75% off the aircraft received a f5 bonus payment in an attempt to simulate a rush for the exits and to motivate participants to try to egress as quick as possible.

Cabin crew behavior was found to have a significant effect upon passenger’s evacuation times. Two Assertive cabin crew produced the fastest mean evacuation times. The results indicated that assertive cabin behavior is of most importance in the initial stages of an evacuation as it sets the speed for the later stages. When passengers received no help from cabin members their evacuation times were significantly slower than those passengers who had received help from assertive and non-assertive cabin crew.

Passengers evacuated faster when two doors rather than a single exit were available however in the latter stages of the emergency evacuations individuals’ egress time was no longer affected by the number of exits available. At this stage fewer blockages and queues at exits occurred subsequently the number of exits available had no effect on passengers’ evacuation times. There was however, no significant difference between the two types of exits utilized in this study.

The number of bonuses a passenger received was found to be significantly affected by gender and age, males received more bonuses as did younger passengers. Passenger’s questionnaire responses also indicated that they perceived assertive cabin crew members to have greatly aided their escape.

J. Michael Barrientos

On April 6, 1993, China Airline’s MD-11 Flight 583 underwent severe turbulence caused by the inadvertent deployment of the wing leading edge slats. The aircraft experienced three violent pitch oscillations and a loss of altitude of about 5000 feet which significantly damaged the interior of the cabin. Upon examination of the passenger seats in the cabin interior, excessive wear was noticed with the fire-blocking layer (FBL) material which encapsulates the foam cushions that protect them in the even of a fire. Concerns arose with this FBL material manufactured by Testori of Italy, as well as other FBL material in service, with regard to their effectiveness in protecting the foam cushions from fire. Samples of this type of material underwent several flammability tests at the FAA Technical Center International Airport, NJ, and chemical analysis and microscopic examination at Du Pont Fibers Laboratory in Wilmington, Delaware.

Robert A. Filipczak

Halon 1301, Halon 1211, and eleven alternative fire-fighting agents were compared for extinguishment effectiveness and thermal decomposition product generation, using a laboratory-scale test apparatus having methane as the fuel. Chemical analysis was conducted using a magnetic sector mass spectrometer with simultaneous measurement of oxygen consumption and carbon dioxide, water and acid gas production. Chemical mechanisms are advanced to explain how halongenated hydrocarbons extinguish fires. The major conclusion was that the alternative agents were not as effective at fighting fires as Halons and those greater amounts of acid gases were produced during extinguishment. Hydrogen fluoride was found to be the predominant thermal decomposition product for all agents.

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.