While X-ray machines are severely limited in keeping modern explosives off airliners, researchers say they have developed a device that can detect bombs inside luggage with uncanny regularity. But no airline has ordered one of the devices, and with the exception of two prototype machines used in a yearlong test program in San Francisco and Los Angeles, no airports have put the machine into operation.
The confirmation Wednesday that a bomb detonated aboard a Pan Am jumbo jet last week over Scotland is likely to spur interest in the new explosives detection device, industry officials say. (Who bombed Flight 103?, Page 7.)
The machine is called Thermal Neutron Analysis device, or TNA, and is about twice the size of an airport X-ray machine. During the yearlong test under a contract from the Federal Aviation Administration it demonstrated a 95 percent detection rate with few false alarms, the agency says.
The FAA recently ordered five more TNAs at a cost of $8.4 million. The agency plans to put them into other United States airports beginning next summer.
``We are now in the production phase. The research and development is over,'' says Hadi Bozorgmanesh, a vice-president for Science Applications International Corporation of San Diego, the developer of the machine. He says the five machines will be used to monitor baggage checked on regularly scheduled flights.
Once the FAA and airlines are convinced of the machines' reliability, the agency will likely require the devices be installed at certain US airports. But that is expected to be several years away, according to agency sources.
Mr. Bozorgmanesh says his company also has had inquiries from foreign governments, including Britain, Japan, and Italy. ``But none of them have put in orders,'' he adds.
Bozorgmanesh says he is confident the machine can detect a variety of explosives, even the plastic type of explosive believed to have been smuggled aboard the Pan Am jetliner in a piece of checked luggage.
Security officials currently use conventional X-ray machines at airport screening points to detect metal parts or wiring that might resemble a bomb. But there are many explosives that can be shaped in a variety of innocent-looking forms, and they are so powerful that a few pounds can rip apart a jetliner.
However, the TNA machine does not look for certain sizes or shapes. Instead, it relies on the fact that all explosives contain large and concentrated amounts of nitrogen.
According to TNA's developers, the machine bombards a piece of luggage with neutrons, which pass through all types of material - even sheets of lead - without a significant reaction. But the nitrogen in explosives absorbs the neutrons and immediately gives off gamma radiation. The gamma radiation gives the luggage a unique signature that can be detected by the machine. The amount of radiation has no significant effect on the suitcase or its contents, Bozorgmanesh says.
The FAA - with a nudge from Congress - stepped up its development of bomb detection devices after a terrorist bomb apparently caused an Air-India jumbo jet to crash off the Irish coast in 1985 and a bomb detonated aboard a Trans World Airlines jet over the Mediterranean in 1986, killing four Americans.
While the technology soon became workable in a laboratory environment, adapting it for use at a crowded airport where thousands of pieces of luggage must be scanned in a short period was more of a challenge.
Raymond Salazar, director of aviation security at the FAA, says initially there were too many false alarms, but those problems appear to have been resolved. ``Our results have been very, very satisfactory,'' he says.
According to the FAA, the device is capable of scanning a piece of luggage in six seconds and can be adapted for use with a conveyor system that could handle large numbers of baggage in relatively short periods of time with a low rate of false alarms.
``You could do an entire Boeing 747 in a half hour or so,'' Bozorgmanesh says.
Each machine now costs more than $1 million, but eventually the cost is expected to range from about $500,000 to $900,000, depending on how many are produced, according to FAA and industry estimates.
``We could produce a lot of them in a short period of time,'' Bozorgmanesh says. But he adds, ``The airlines are not lined up right now to purchase these things. We have to demonstrate to them that it works.''