For Immediate Release
March 24, 2006
Contact: Les Dorr, Jr.
Phone: (202) 267-3883
The Key to Survival
It’s rare that passengers have to evacuate a commercial airliner in an emergency, but when it’s necessary, they must do it as quickly and as efficiently as possible.
Before airliners receive Federal Aviation Administration (FAA) certification, the manufacturer must prove that passengers can exit the aircraft quickly enough to comply with regulations. And over the years, the agency has upgraded cabin safety requirements to make it more likely that passengers will survive an aviation accident. Most U.S. commercial airplanes have numerous FAA-required features— such as floor path emergency lighting, fire-resistant seat cushions, low heat and smoke release cabin materials, and improved cabin insulation — to give passengers and crew enough time to make a speedy evacuation.
Passing the Test
FAA certification requirements on emergency evacuations are relatively simple, and are intended to ensure that airplane design and crew training provide a consistent level of safety across all the airplane models in the commercial fleet.
Federal regulations specify that the manufacturer of an airplane with more than 44 passenger seats must show that the maximum number of crew and passengers can evacuate the airplane under simulated emergency conditions within a time specified in the regulations. An actual full-scale demonstration is required unless the applicant can demonstrate to the satisfaction of the FAA that a combination of tests and analysis will yield equivalent data.
The regulations also spell out detailed conditions under which a full-scale evacuation demonstration must take place. They specify things such as the lighting conditions, configuration of the aircraft and the age and gender mix of passengers. One of the most important conditions is that the passengers must be “naïve”, i.e., they may not have not participated in a similar type of demonstration for at least six months.
When the evacuation begins, the test passengers are directed to exit the plane just as they would in an actual emergency. The evacuation time period is up when the last person (passenger or crew member) has left the airplane and is on the ground.
Since the 1960s, the FAA’s Civil Aerospace Medical Institute (CAMI) in Oklahoma City, OK, has been recognized as a world-renowned center for research on technical issues and human behavior associated with emergency aircraft evacuations.
CAMI’s Cabin Safety Research Team supports FAA regulatory and airworthiness functions through studies on seating density, exit size and location, passenger flow rates through exits and flight attendant behavior. The studies are done using an aircraft cabin evacuation facility and human research subjects. For the future, a Boeing 747 evacuation facility is coming on line to enhance the study of exit problems encountered on larger aircraft with higher door sill heights and multiple aisles.
Improvements to Cabin Safety
A number of FAA-mandated improvements to cabin safety are designed to give passengers and crew more time to evacuate an airliner. Some examples are:
- Seat cushions: Air carriers had until Nov. 1987 to comply with a new regulation that required the installation of new fire-blocking layers on aircraft seat cushions. Air carriers replaced 650,000 foam seat cushions on the U.S. fleet. FAA research found that the new material did a better job retarding burning and provided 40 to 60 seconds of additional time for aircraft evacuation. All existing seats in the U.S. fleet meet the improved standards.
- Floor lighting: By 1986, the U.S. commercial fleet was retrofitted with floor proximity lighting, marking the completion of a two-year compliance schedule. Since smoke rises and can obscure overhead lighting, the FAA determined that floor lighting could improve the evacuation rate by 20 percent under certain conditions.
- Improved interior materials: In 1985, the FAA developed a new test standard for aircraft ceilings, walls, overhead bins and partitions. The agency required that all commercial aircraft built after Aug. 20, 1988 have panels with reduced heat and smoke emissions, delaying the onset of a fire “flashover.” Although there was no retrofit of the existing fleet, the FAA requires that these improved materials be used during major cabin refurbishment.