Cockpit doors may be bulletproofed with a unidirectional sheet made of an ultrahigh-molecular-weight polyethylene fiber
|called Dyneema UD-HB25 that is 15 times stronger than steel.|
The first bulletproof cockpit door to be officially certified by the FAA is made from a composite containing ultrahigh-molecular-weight polyethylene (UHMW PE) fiber. The Dyneema fiber from the High Performance Fibers Div. of Netherlands-based DSM (www.dsm.com) is reportedly 15 times stronger than steel on a weight-for-weight basis. The fibers have been used in other defense applications including lightweight bullet-resistant vests, helmets, and armored vehicles. But the fiber's use in the civil-aircraft industry is new.
The cockpit doors were designed by C&D Aerospace Inc., Huntington Beach, Calif. (www.cdaero.com), and are slated for use by American and United Airlines, Delta, Lufthansa, British Airways, and KLM. They will be used aboard Boeing 737s and 757s, various types of McDonnell Douglas aircraft, and planes manufactured by Bombardier and Embraer.
Cockpit protection now ranks high on the list of priorities for aviation authorities. The FAA has taken the lead by issuing the regulation that all domestic and foreign aircraft flying into and in the U.S. must soon be fitted with a bulletproof cockpit door certified by the agency.
DSM produces Dyneema fiber via a patented gel-spinning process. The material is also used in ropes, fishing lines, cordage, nets, and protective clothing.