Long After Lockerbie, Air Safety Still a Worry : Airlines: Despite improvements, security guards and conventional X-ray machines can still be fooled by the plastic explosive that blew up Pan Am Flight 103.

The terrorist bomb that blew apart a Pan Am 747 over Lockerbie, Scotland, two years ago last Friday exposed critical gaps in airline security that are not yet closed today, even as experts say Mideast tensions could heighten the prospects for disaster in the skies.

Aside from tedious and time-consuming hand searches, there is still no reliable way to find a bomb such as the one that destroyed Pan Am Flight 103 and left its 259 passengers dead.

Experts say the science of bomb detection continues to lag behind the dark talents of bomb makers, who have learned to defy a security network designed largely to frustrate hijackers. Scientists have yet to come up with a machine that can quickly and accurately spot deadly explosives.

The art of screening passengers to isolate potential terrorists--a technique pioneered by the vaunted Israeli security system--remains unsophisticated elsewhere and relies almost entirely on the questionable instincts of security guards.

Security is “totally inadequate,” said Washington security consultant Billie Vincent, a former Federal Aviation Administration security chief. “We are still extremely vulnerable to a (Lockerbie)-type device.”

Fortunately, the risk of a terrorist attack on an American airliner is extremely small, even on international flights. On average, there is just one bombing incident involving an American airliner on any of the 6.5 million departures a year.

“It is a statistically insignificant threat,” said Richard Lally, vice president-security for the Air Transport Assn., the industry lobby. “Of course, it is not so insignificant when you are the statistic.”

In the view of several experts, the terrorist threat--although still low within the United States--has increased generally since Iraq’s Aug. 2 invasion of Kuwait.

The man believed by some investigators to have invented the sort of bomb that blew up Pan Am Flight 103 lives in Baghdad, the Iraqi capital. Frank Maguire, a terrorism expert based in Washington, believes that terrorists are in place in strategic locations worldwide, waiting for the word from Iraqi leader Saddam Hussein to strike.

It is possible that Maguire’s vision exaggerates the potential danger, but few deny that a war involving the United States and Iraq would put American airliners at risk.

Clyde E. Robbins, a retired Coast Guard vice admiral who in June became the Department of Transportation’s first intelligence and security director, said the Persian Gulf crisis has indeed heightened the terrorist threat in Europe.

Although he believes that the threat in the United States at this time is low, Robbins has ordered the airlines to prepare “contingency plans for a higher (security) level.”

Citing a need for secrecy, Robbins would not say what intensified security measures would involve.

The government has taken a number of steps lately to tighten security, prompted in part by a presidential commission that took an exhaustive look at U.S. safety measures in the wake of the Lockerbie bombing.

The FAA has ordered tighter screening of bags on overseas flights--more X-raying and pairing baggage with passengers--and has deployed advisers to work out security kinks in foreign countries.

The agency has also stepped up its research into bomb detection and is working on tougher training standards for security guards. Transportation Secretary Samuel Skinner, who oversees the FAA, appointed Robbins as a sort of security czar, responsible for getting the system into shape.

In addition, the Aviation Security Act, passed in October, requires the FAA to draw up tougher safety regulations for foreign carriers that operate here.

A number of U.S. airlines have improved security beyond what is required.

Pan Am--highly criticized for security lapses in its inspection of bags loaded on its doomed Flight 103--has taken steps to make travel safer. It has, for instance, purchased a number of sophisticated X-ray machines that produce a color-coded image of the contents of a suitcase. An orange color may indicate a potential explosive, but the system is not foolproof.

Pan Am, the largest transatlantic carrier, said that since 1987 it has quadrupled the amount spent on security to $63 million this year.

Robbins said steps taken by the airlines and the government have helped produce a security system that is better than it was two years ago. But he added: “Let me hasten to say that it is not perfect. . . . There is considerably more work to be done.”

The task is a tricky one, complicated by a Byzantine structure in which the government makes the rules but leaves execution up to each airline. The airlines, in turn, generally don’t undertake security measures themselves, hiring outside contractors instead.

The situation is even more complex in international travel; it is not unusual for regulations in foreign countries to conflict with U.S. safety rules.

For instance: France until mid-1989 outlawed hand searches by non-government security forces, so American air carriers were forced to choose between loosening security or breaking French law.

“An airline has no bargaining position with a foreign government,” said Charles A. Adams, Trans World Airlines senior vice president-international. “We often have no choice but to comply.”

The airline industry has long argued that the U.S. government should get more involved in smoothing out international security conflicts. Four months ago, the FAA for the first time dispatched 27 advisers to Europe and the Middle East to work with governments in those regions.

The industry thinks more advisers are needed to cover such a geographic expanse. Nonetheless, the advisers helped with some thorny security problems.

At Madrid’s airport, for example, Spanish authorities allowed curbside parking outside a terminal used by TWA, Pan Am and American Airlines. Adams said TWA objected to the practice, because a bomb planted in a car parked outside the terminal “could level the whole building.”

Spanish authorities agreed to restrict parking, he said, only after the FAA advisers got involved.

In another case, TWA refused to move to a terminal at Paris’ airport set aside for high-security flights to Israel. “It is the worst thing you can do, isolate the target,” Adams explained. French authorities, again under pressure from the U.S. government, ultimately backed down.

These steps, although undoubtedly reducing risk, leave unchanged a security network that largely relies on low-paid security guards, metal detectors and conventional X-ray machines that readily spot guns or knives but are easily fooled by the sort of sophisticated plastic explosive that blew up Pan Am Flight 103.

Semtex, the explosive material used in the Lockerbie bombing, can be molded like clay to take on a shape that would not alarm an X-ray operator, such as that of a shoe. The explosive can also be rolled into a sheet less than one-quarter of an inch thick and used to line a suitcase.

Since the explosive itself is hard to spot, security guards must look for electronic devices that could double as detonators: radios, calculators, cameras or other gadgets commonly found in suitcases.

Tests conducted by the FAA don’t give security guards much practice at finding plastic explosives. Instead, Maguire said, the agency’s inspectors try to slip by guards a suitcase that contains three sticks of dynamite and an alarm clock.

“These people do not have the training, nor do they have the equipment,” to find a Lockerbie-type explosive, said Maguire, who publishes the Counterterrorism and Security Intelligence newsletter.

Robbins, the DOT security director, acknowledged that training for security guards needs to be improved. Security guards need “more formal training and should be tested more often,” he said. “And not just tested to catch FAA people with firearms.”

As for bomb-detection technology, several manufacturers have come up with complicated, high-technology machines to search for the new plastic explosives that are invisible to conventional X-rays. One machine bombards suitcases with atomic particles. Another “sniffs” baggage, looking for chemical traces of explosives. And there’s the color X-ray that is supposed to indicate explosives by an orange tint.

So far, none of these machines is a reliable bomb detector. Some are too slow. Others are easily tricked by molecules in perfumes or clothing.

Some security experts, such as Caltech Professor John Baldeschweiler, argue that some of these machines should be selectively deployed now anyway.

“If I were in charge, I’d deploy prototypes right now to see how they work in the field,” said Baldeschweiler, who chaired a National Academy of Sciences committee that looked into airport security. “The result from the field is never the same as in a laboratory.”

Baldeschweiler said several machines--such as a chemical sniffer and an enhanced X-ray--should be used in tandem to reduce false alarms. If the first machine makes a mistake, the second machine might catch it, he said.

“I don’t think there will ever be a single perfect technology,” he said.

But Robbins said he is reluctant to order airlines to buy equipment that is not fully effective. “I’d like to see more out there, and color X-rays are better than black-and-white X-rays,” he said. “But I’d hate to order their use and not look to the future” when a better device might be available.

Experts say even a perfect security system would strain under the enormity of the task. Airliners leaving U.S. airports carry 1 billion bags each year. Security equipment--normally metal detectors or X-rays machines--have just 4 to 6 seconds to scan each suitcase or carry-on parcel. A longer look could delay a flight.

It was the potential for delays, among other things, that derailed the so-called TNA machine, a 10-ton, $1-million contraption that bathes luggage with invisible neutrons to find explosives.

Touted as a breakthrough when it was introduced a year ago, the thermal neutron analysis machine is now widely dismissed as a dud. Though built to FAA specifications, the machines are not sensitive enough to detect bombs as small as the one that destroyed Pan Am Flight 103--without many false alarms.

The machines look for nitrogen, an element commonly found in explosives. The machines can be tricked by other nitrogen-rich items frequently packed in luggage, such as wool sweaters and ski boots. The high number of false alarms means that an average of 30 or more bags on a jumbo jet would have to be hand-searched, a situation that the airlines say would result in unacceptable delays.

The airlines also object to the machine’s cost and size. The ATA’s Lally said it would take 40 machines to screen TWA’s international luggage at New York’s John F. Kennedy International Airport alone.

The machines were advocated by the families of the victims of Pan Am Flight 103, who argued the detectors were better than nothing at all.

“It is not a perfect technology, but it is better than hand-searches and X-rays,” said Michael R. Lemov, the Washington lawyer who represents the families. Lemov said the device could be used to screen suspicious bags, and the Transportation Department’s Robbins says the machines--which are being fine-tuned--might eventually be used that way.

For now, the FAA has deployed four machines at airports in New York, Miami, Washington and London. But under pressure from the presidential commission and Congress, the agency has put on hold earlier plans to order their installation at 40 airports.

The commission members and others worry that wide deployment of the machines would stifle research on potentially better devices.

“What we have,” said Lee Grodzins, a Massachusetts Institute of Technology professor and adviser to the FAA, in a remark that could well describe the nation’s security system, “is a brilliant technology that unfortunately was designed for the last war.”