LOS ANGELES (AP) - For a nation shattered by an airborne apocalypse, no idea for boosting safety in the skies may seem too expensive or too far-fetched.
Computers that match the faces of airline passengers against databases of known terrorists? Fingerprint readers to secure cockpits? Planes that can be wrested from the control of hijackers and landed safely by pilots stationed on the ground?
The disaster will spark a wholesale review of airline security, aviation experts say. Potential solutions could be as simple as saturating flights with armed sky marshals - or as complex as technology that identifies passengers by the whorls of their fingerprints.
''One of the small benefits from huge disasters is a rethinking of where we are, and we must do that,'' said Tsahi Gozani, president and chief executive officer of Ancore Inc., a Santa Clara-based maker of advanced bomb-detection equipment. ''We must leap forward.''
Safety experts predict advanced technologies, some of which exist now only in concept, will play an increased role.
''It's conceivable that the next generation of airplanes may be able to have some feature where in the event of a catastrophic incapacitation of pilots ... maybe there's a way for the aircraft to lock up its cockpit and turn over to some kind of ground-based control,'' said James Coyne, president of the National Air Transportation Association in Alexandria, Va.
Grant Evans, executive vice president of Identix Inc., said fingerprint readers made by his Los Gatos, Calif., company could confirm the identity of passengers and keep cockpits locked to all intruders.
''One of the things you can avoid is plane hijacking, by knowing who's on the plane,'' Evans said. ''The technology's been there. There just hasn't been the cause.''
Some believe the attacks will prompt the use of biometric systems that scan faces of passengers in a digital hunt for possible terrorists.
Luggage scanners, like those being developed by Ancore, can measure the chemical composition of a bag's contents, sniffing out weapons and bombs. The U.S. Department of Energy is developing a holographic scanner that can image a passenger in three dimensions to reveal any hidden weapons.
The scanner uses wavelengths similar to radar or satellite signals, but not X-rays, to illuminate a person. The signals are then read by multiple detectors before being fed to a computer, which produces a 3D image of the person's unclothed body. To address privacy concerns, researchers program the computer to see only objects.
Others propose radically boosting the number of armed Federal Aviation Administration sky marshals (the current number is not publicly divulged but is believed relatively small) or adding armored cockpit doors.
Airlines could ban carry-on luggage or force passengers to place it in overhead bins that lock. Computer-assisted passenger profiling also could be stepped up.
Airlines have profiled some passengers since 1998. The programs identify those most likely to present a security risk but has come under fire by civil liberties groups.
Asked when advanced technology should be deployed, Rep. John Mica, R-Fla., said ''yesterday.'' Mica is chairman of the House aviation subcommittee, which will meet this week to considered heightened security measures that include the use of sky marshals and a ban on carry-on luggage.
Investigators, however, should determine what part of the system failed before completely overhauling airport security, said Richard Bloom, director of terrorism, intelligence and security studies at Embry-Riddle Aeronautical University in Prescott, Ariz.
''By changing things now, you could potentially make them worse,'' Bloom said. ''Or you might change things in a way that indeed makes a system that looks better, but you'd correct a system that has nothing to do with what happened.''
Indeed, even the most high-tech measures may be powerless against a low-tech approach taken by suicidal terrorists. The hijackers in last week's destruction of the World Trade Center and Pentagon attack are believed to have been armed with little more than knives and box cutters, pilot training and a will to die.
More stringent security measures already are in place at the nation's more than 400 airports, including a ban on knives. Previously, the Federal Aviation Administration allowed blades of less than four inches to be carried on board.
No matter what measures are taken, there never will be a system that can ensure complete safety, said Brian Jenkins, a Rand Corp. consultant and former member of the White House Commission on Aviation Safety and Security.
''If we want to fly commercial airlines, load them with hundreds of passengers, freight, baggage, make them a convenient form of travel, keep to tight schedules and get them to their destinations, we are going to make hundreds of compromises on security,'' he said. ''We can always increase security, but can we prevent all terrorist attacks? No.''
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AP Business Writer Brian Bergstein in San Jose contributed to this report.
