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| DOT/FAA/AR-99/57 [169 PAGES 1.3Mb] | TOP OF PAGE |
FUSELAGE
BURNTHROUGH PROTECTION FOR INCREASED POSTCRASH OCCUPANT SURVIVABILITY:
SAFETY BENEFIT ANALYSIS BASED ON PAST ACCIDENTS
The objective of this analysis was to assess the potential benefits, in terms of reduction of fatalities and injuries, resulting from improvements in fuselage burnthrough resistance to ground pool fires. The process employed for assessing benefit is considered to give reasonably accurate and consistent results within the limitations imposed by the available data. The methodology gives a reasonable assessment of the tolerance on the predicted levels.
| DOT/FAA/AR-TN99/65 [14 PAGES 934Kb] | TOP OF PAGE |
MASS LOADING
EFFECTS ON FUEL VAPOR CONCENTRATIONS IN AN
AIRCRAFT FUEL TANK ULLAGE
AIRCRAFT FUEL TANK ULLAGE
This report discusses experiments performed within a simulated fuel tank approximately 1/20 the size of a typical B-747 center wing fuel tank (CWT). The vapors generated within the ullage of this tank were analyzed under different mass loadings in an effort to determine the effects of the mass loading and fuel distribution. It was determined from these tests that in order to have a substantial effect on the flammability of the vapor within the CWT, the mass loading would have to be somewhere between 0.08 and 0.15 kg/m 3 . A substantial effect was defined as a minimum 20% decrease in the maximum hydrocarbon count when compared to the average of all tests conducted with larger mass loadings. In addition, it was found that while the distribution of the fuel has no effect on the peak flammability (vapor composition) that is reached, it does have a significant effect on how long it takes to reach the final state. The less dispersed the liquid fuel is, the longer it will take the vapor to reach its maximum flammability point.
| DOT/FAA/AR-TN98/32 [25 PAGES 605Kb] | TOP OF PAGE |
CARGO COMPARTMENT
FIRE PROTECTION IN LARGE COMMERCIAL
TRANSPORT AIRCRAFT
TRANSPORT AIRCRAFT
This report describes recent research by the Federal Aviation Administration (FAA) related to cargo compartment fire protection in large transport aircraft. A gaseous hydrofluorocarbon, HFC-125, was compared to Halon 1301 in terms of fire suppression effectiveness and agent decomposition levels in the cargo compartment and passenger cabin during full-scale tests involving a bulk-loaded cargo fire.
| DOT/FAA/AR-TN99/29 [11 PAGES 515Kb] | TOP OF PAGE |
(To view the figures you must have Adobe Acrobat Reader 4.0 or later.)
Effectiveness
of Flight Attendants Attempting to Extinguish Fires in an Accessible
Cargo Compartment
This technical note documents the results of a project to evaluate the ability of flight attendants to extinguish cargo fires in small Class B cargo compartments. Thirteen fire tests were conducted in a modified Shorts 330 airplane in which flight attendants attempted to extinguish cargo fires. Some of the selected test variables included the cargo compartment size, the width of the access door, the size and type of fire extinguishers available, the presence and absence of an unobstructed center aisle in the cargo compartment, the type of Protective Breathing Equipment (PBE), and the delay between the smoke detector alarm and the start of the firefighting efforts. The results of the testing indicated that in most cases the flight attendants were unable to successfully extinguish these fires.
| DOT/FAA/AR-TN98/29 [16 PAGES 1.2Mb] | TOP OF PAGE |
(To view the figures you must have Adobe Acrobat Reader 4.0 or later.)
Oxygen
Enhanced Fires in LD-3 Cargo Containers
Four tests were conducted inside a 169-cubic-foot LD-3 cargo container to demonstrate the hazards associated with the release of gaseous oxygen during suppression of a smoldering fire with Halon 1301. The cargo fires were allowed to burn for a short duration before Halon 1301 was discharged into the container. After the suppressant concentration stabilized to about 3%, the minimum design concentration for inerting, a quantity of oxygen was discharged to simulate the relief of oxygen from an overpressurized cylinder. During the first three tests, 11 cubic feet of oxygen was bled into the container from a remote cylinder. A fourth test was conducted in which 22 cubic feet of oxygen was introduced which produced a severe fire that destroyed the container. Temperature, toxic gases, and halon concentration were measured continuously inside the container and video cameras recorded the tests from three locations external to the container.
| DOT/FAA/AR-TN98/30 [19 PAGES 409Kb] | TOP OF PAGE |
Evaluation
of Oxygen Cylinder Overpacks Exposed to Elevated Tempature
Tests were conducted inside a large industrial convection furnace to determine the temperature and time required to cause pressure relief activation of three different size oxygen cylinders commonly used in commercial transport aircraft. The cylinders were first emptied of gaseous oxygen for safety reasons and refilled with nitrogen to the original pressure. The furnace temperature was ramped to 400°F, which represented the temperature reached during a Halon 1301 suppressed deep-seated cargo compartment fire. Cylinder pressure relief activation typically occurred after the surface temperature had reached only 300°F.Additional tests were conducted using a 76.5-cubic-foot oxygen cylinder placed inside several types of cylinder cases, commonly referred to as overpacks. The overpacks were available in a variety of constructions, all for the purpose of protecting the cylinder from impact damage that may occur during shipment. The tests were run to determine the level of thermal protection, if any, that the overpacks might provide when the cylinders are subjected to elevated temperatures. Two custom-made overpacks were also tested that contained insulating materials aimed specifically at providing thermal protection. Tests showed that some common overpacks have the ability to protect the cylinder from pressure relief activation for nearly 60 minutes while other types designed specifically for thermal insulation can provide significant additional protection.
DOT/FAA/AR-98/52 [41 PAGES. 1.8 Mb] |
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Full-Scale
Test Evaluation of Aircraft Fuel Fire Burnthrough Resistance
Improvements
This report summarizes the research and full-scale tests undertaken by the Federal Aviation Administration (FAA) to evaluate the fuselage burnthrough resistance of transport category aircraft that are exposed to large postcrash fuel fires. Twenty-eight full-scale tests were conducted in a reusable fuselage test rig to determine the effectiveness of thermal-acoustical insulation improvements in preventing or delaying fuselage burnthrough. The testing showed that the method of attaching the insulation to the fuselage structure had a critical effect on the effectiveness of the insulation material. In addition, the composition of the insulation bagging material, normally a thermoplastic film, was also shown to be an important factor. A number of fiberglass insulation modifications and new insulation materials were shown to be effective in varying degrees. For example, a heat-treated, oxidized polyacrylonitrile fiber (OPF) encased in a polyimide bagging material prevented burnthrough for over 8 minutes. When contrasted with current insulation materials, which were shown to fail in as little as 2 minutes, effective fire barriers such as the OPF insulation offer the potential of saving lives during a postcrash fire accident in which the fuselage remains intact.
DOT/FAA/AR-98/26 [62 PAGES. 1.04 Mb] |
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A Review
of the Flammability Hazard of Jet Fuel Vapor in Civil Transport
Aircraft Tanks
This report documents the findings of a Fuel Flammability Task Group made up of recognized fuel and combustion specialists investigating the flammability and explosiveness of fuel within an aircraft fuel tank. The task group reviewed all available reports on the subject and met and discussed the data with technical experts from Boeing Commercial Airplane Co., California Institute of Technology, and the National Transportation Safety Board. The scope of the report includes jet fuel definitions and specifications, jet fuel flammability data, influences of various factors on fuel flammability, and predictive analyses and models for flammability. The report discusses the impact of this knowledge on the needs for in-flight fuel fire prevention.
DOT/FAA/ARTN-97-103 [16 pages 500k] |
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Initial
Development of an Exploding Aerosol Can Simulator
A device was constructed to simulate an exploding aerosol can. The device consisted of a cylindrical pressure vessel for storage of flammable propellants and base product and a high-rate discharge (HRD) valve for quick release of the constituents. Simulator tests were conducted using representative constituents and propellant quantities for comparison with actual cans heated to the point of rupture and ignition. This report describes the tests conducted with the simulator in unconfined spaces, a B-727 cargo compartment, and an LD-3 Unit Loading Device (ULD). Subsequent work is planned with the aim of matching the ressure pulse produced by the exploding aerosol can simulator with that measured during an overheated aerosol can explosion.
DOT/FAA/AR-97/58 [23 pages, 82k] |
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Evaluation
of Fire Test Methods for Aircraft Thermal Acoustical Insulation
Round robin flammability testing was performed by eight laboratories on thermal acoustical insulation blankets and films used as insulation coverings. Test samples were subjected to vertical Bunsen burner testing and cotton swab testing. The test data indicated that the cotton swab test produced consistent test results, whereas the vertical flammability test did not.
DOT/FAA/AR-97/9 [20 pages 228KB] |
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An Acoustic
Emission Test for Aircraft Halon 1301 Fire Extinguisher Bottles
An acoustic emission test for aircraft Halon 1301 bottles has been developed, a prototype acoustic emission test system constructed, and over 200 used bottles tested at the repair facilities of the two manufacturers of these bottles. The system monitors a bottle with six acoustic sensors while the pressure of the bottle is raised by heating it in an oven. The sensors are held in position, with a fixed relationship between them, by a special fixture. This fixture is designed to fit spheres with diameters between 5 and 16 inches. Results of the tests on used bottles indicate that over 95 percent of the bottles showed no indication of significant defects. The rest had some indication of flaws or corrosion. However, all bottles tested to date have passed the hydrostatic test required by the U.S. Department of Transportation. Based upon this data, the Air Transport Association (ATA) requested an exemption from the DOT to allow their members to use this acoustic emission test in place of the hydrostatic test. This exemption, DOT-E 11850, was granted to the ATA on December 11, 1997.
DOT/FAA/AR-96/122 [62 pages, 713k] |
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Development
of a Minimum Performance Standard for Lavatory Trash Receptacle
Automatic Fire Extinguishers
This report contains a summary of the work performed during the development of a minimum performance standard for lavatory trash receptacle automatic fire extinguishers. The developmental work was performed under the direction of the International Halon Replacement Working Group.
DOT/FAA/AR-96/15 [38 pages, 158k] |
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The Development
of a Flammability Test Method for Aircraft Blankets
Flammability testing
of aircraft blankets was conducted in order to develop a fire
performance test method and performance criteria for blankets
supplied to commercial aircraft operators. Aircraft blankets
were subjected to vertical Bunsen burner testing, 4-ply vertical
testing, full-scale match and cigarette testing, and single-
and 4-ply horizontal testing. It was found that the 4-ply horizontal
test correlates well with the full-scale match tests, produces
consistent test results, and realistically evaluates ease of
ignition.
ARAC Report:
Fuel Tank Harmonization Working Group - FINAL REPORT
Executive
Summary
TOR
Organizational
Chart
Task
Group 1 – Service History/Fuel Tank Safety Level Assessment
Final Report
Task Group 2 – Explosion Suppression
Final Report
Task Group 3 – Fuel Tank Inerting
Final Report
Task Group 4 – Foam Final Report
Task Group 5 – Fuel Vapor Reduction
Final Report
Task Group 6/7 – Fuel Properties
- Effect on Aircraft and Infrastructure Final Report
Task Group 8 – Evaluation Standards
and Proposed Regulatory Action Advisory Group Final Report
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LAST UPDATED 9/24/99