FAR Part 25 Standards
Prior to 1990, most cabin composites were epoxy-based. But in 1987, the U.S. Federal Aviation Admin. (FAA) mandated slower burn rate/flame spread in aircraft seat cushion materials in its Federal Aviation Regulation (FAR) Part 25 standards. Then, in 1990, it also established regulations that mandated stringent flame/smoke/toxicity (FST) and heat release characteristics for all other cabin interior components. Equivalent European regulations have been formulated by the European Aviation Safety Agency (EASA). Further, OEMs Boeing and Airbus followed suit and often require even more rigorous fire resistance to ensure that the entire interior will work in concert to meet the agency specifications. As a result, interior suppliers have switched to phenolic resins and high-performance thermoplastic resins to ensure compliance with FST rules. According to the FAA, the 1990 regulations provide an additional two to four minutes for escape in the event of fire. The ultimate goal of FAA's Fire Safety Branch is cabin interiors made with "zero heat release"materials (that is, completely fire resistant) by the year 2010, according to the group's Web site. While research is progressing, wholesale changes are likely a long way off.
Interior materials undergo destructive testing to determine their fire performance as dictated by FAR 25.853, as part of the qualification process. The Ohio State University (OSU) Rate of Heat Release test is the accepted measure of heat evolution energy during burning. Generally reported as peak heat release (kilowatts per square meter) and total heat release (kilowatts per minute per square meter), the FAA regulatory peak/total requirement number is 65/65. All suppliers today easily meet that goal and many have products that surpass it. Assuming the materials can meet the mechanical and fire tests, OEMs also evaluate material odor, tack level, handling, shelf life, cosmetics and processibility to complete the qualification process.