- Author
- Marker, T.
- Title
- Development of Improved Flammability Criteria for Aircraft Thermal Acoustic Insulation. Final Report.
- Coporate
- Federal Aviation Administration, Atlantic City International Airport, NJ
- Report
- DOT/FAA/AR-99/14, September 2000, 86 p.
- Distribution
- AVAILABLE FROM National Technical Information Service (NTIS), Technology Administration, U.S. Department of Commerce, Springfield, VA 22161. Telephone: 1-800-553-6847 or 703-605-6000; Fax: 703-605-6900; Rush Service (Telephone Orders Only) 800-553-6847; Website: http://www.ntis.gov
- Keywords
- thermal insulation | flammability | burnthrough (failure) | heat release rate | small scale fire tests | fuselages | radiant panel test method | flammability testing
- Identifiers
- vertical bunsen burner; cotton swab test; burnthrough test; in-flight fire tests; postcrash fire tests; proposed in-flight flammability test standard for aircraft thermal acoustic insulation; proposed postcrash burnthrough test standard for aircraft thermal acoustic insulation materials
- Abstract
- This report discusses the development of new flammability test standards for aircraft thermal acoustic insulation. Currently, a vertical Bunsen burner test is the only Federal Aviation Administration (FAA) requirement for fuselage thermal acoustic insulation materials, including those used to insulate ductwork beneath floors, behind the sidewall, and in the cheek areas. Several in-flight and ramp fires between 1993 and 1995 focused attention on the flammability of the insulation materials. Consequently, a series of tests were conducted which exposed the inability of the vertical Bunsen burner test method to discriminate between materials that allow flame propagation and materials that do not. A test originally developed and used by the aircraft manufacturers, involving the placement of flaming cotton swabs on the film surface, was evaluated. However, large-scale tests and in-service experience indicated that the cotton swab test was not severe enough, prompting additional research to develop a more realistic test. After conducting a variety of mock-up tests in small-, intermediate-, and full-scale test rigs, the flame characteristics of the very thin moisture barrier films were more fully understood, leading to the selection of a radiant panel test apparatus as an appropriate method for determining the in-flight fire resistance characteristics. In addition to fire resistance, the ability of the insulation to resist flame penetration, or burnthrough, by a postcrash fuel fire was also studied. A number of postcrash fire accidents have occurred in which the spillage of jet fuel and the ensuing fire have destroyed aircraft and caused fatalities. A full-scale test rig was developed to evaluate the burnthrough resistance of current materials and to determine if alternate materials could be used to prevent or delay the occurrence of fuselage burnthrough. Test results indicated that significant gains in fuselage burnthrough resistance could be realized by altering or replacing the existing fiberglass-based insulation. Select materials are capable of increasing the fuselage burnthrough resistance by several minutes when exposed to a fully developed fuel fire. Based on the full-scale tests, a laboratory test was developed and numerous insulation material combinations were tested. The new test method employs an oil-fired burner, which is currently used for other flammability tests, including the seat fire-blocking and cargo liner tests. Insulation materials compliant with the new burnthrough test method will provide a minimum of 4 minutes of protection against a postcrash fuel fire.