The recent crash of the Asiana Airlines Boeing 777 crash at San Francisco International Airport fortunately had a minimum loss of life. The plane carried 226 passengers and 16 crew and despite breaking up on impact and fire breaking out on board there was a loss of just two lives.
Part of the reason for this is that the US Federal Aviation Administration (FAA) has implemented many rules which have increased the ability for passengers and crew to survive crashes. These have to do primarily with seat structure and more stringent flammability controls.
A summary of those which directly affect the passenger section and fuselage are as follows:
• Improved flammability of seat cushions: An FAA rule required that cushions installed on passenger and flight attendant seats comply with a significantly more stringent flammability test standard using a 2 gallon per hour kerosene burner. The FAA found that the new material did a better job retarding burning and provided 40 to 60 seconds of additional time for aircraft evacuation.
• Floor Proximity Emergency Escape Path Marking: Since smoke rises and can obscure overhead lighting, the FAA determined that floor lighting could improve the evacuation rate by 20 percent under conditions when there is significant smoke in the cabin. The floor proximity marking system aids passengers by marking evacuation paths and identifying exits utilizing illumination sources located close to the floor.
• Lavatory smoke detectors: The FAA requires air carriers to install smoke detectors in lavatories.
• Lavatory fire extinguishers: The FAA also requires air carriers to install automatic fire extinguishers in the waste paper bin in all aircraft lavatories.
• Halon fire extinguishers: The FAA requires two Halon extinguishers per aircraft, in addition to other required extinguishers.
• Improved interior materials: The FAA has developed a new test standard for large surface area panels, e.g., ceilings, walls, galleys, overhead bins and partitions. This improvement in cabin material flammability has been demonstrated to delay flashover in the cabin. Flashover is the point in time, during a fire, when conditions are generally considered to no longer support life.
• Cargo compartment liners: In 1986, the FAA issued a new test standard using the 2 gallon per hour kerosene burner to improve fire safety in Class C and D cargo and baggage compartments. Maintaining the integrity of the Class C compartment liner allows the required extinguishing agent more time to extinguish the fire. Subsequent to this rulemaking class D cargo compartments were effectively banned from installation in passenger carrying airplanes.
• Cargo compartment fire detection/suppression: In 1998, the FAA required that all large passenger aircraft have fire detection and suppression systems installed in all cargo compartments.
• Thermal/acoustic insulation: In May 2000, the agency required that operators of more than 600 aircraft replace insulation blankets covered with metalized polyethylenteraphthalate (MPET) within four years. Replacement materials had to meet a new flame propagation standard that had been developed in 1999.
• 16G seats: In 1988, the FAA issued regulations requiring that all newly developed transport aircraft use “16g” seats. Using a test dummy, these seats undergo dynamic testing and evaluation regarding injury protection. Similar to automobile crash tests, the FAA tests are designed specifically for the aviation environment.
• Improved Access to Type III Exits: In 1994, the FAA improved the access to Type III exits, by specifying minimum standards for the passageway from the aisle to the exit for airplanes with 60 or more passengers. Egress rates through the exits were found to be approximately 14% faster than through the earlier allowed narrower passageways.