Experts: better air security possible. Closer check of bags, passengers suggested

Can international airport security be further tightened? Or have the heavy investments already made in airport security carried airline safety about as far as it can go?

In the minds of many travelers, that's the frustrating question that remains in the wake of Wednesday's bombing of TWA Flight 840 en route from Rome to Athens -- two airports which, in recent years, have seen more than their share of terrorist incidents.

``The level of frustration is not surprising when one thinks of the previous attacks along these routes,'' says Prof. Paul Wilkinson of the University of Aberdeen in Scotland and a widely respected specialist in international terrorism.

He insists, however, that ``there is much more that we can do'' -- and that airlines really can become more secure.

Last month's report by Vice-President George Bush's Task Force on Combatting Terrorism comes to similar conclusions. The report notes that, since 1972, the pre-flight screening of passengers and carry-on baggage have ``detected over 30,000 firearms and resulted in 13,000 arrests.'' It calls, however, for ``updated security procedures'' and generally tougher antiterrorism measures.

Harvey J. McGeorge, an explosives expert and former Secret Service officer at the White House, who now runs his own security firm, agrees. Fresh from organizing security for a conference at the Rome airport, he worries that security at European airports in general is much more lax than in US terminals. ``We take security much more seriously,'' he says, ``and are much less willing to compromise it.''

How can airport security be tightened?

``The model must be El Al,'' says Professor Wilkinson, referring to the Israeli national airline. ``They have been flying for years in the most dangerous part of the world with very few incidents,'' despite constant terrorist threats.

Recent attacks against El Al, he says, have not been in the air but at their airport facilities and offices, where responsibility for security has been partly in the hands of the host nations. Another successful example, he adds, is British Airways on its London-Belfast shuttle -- where, again, the risk of terrorism is high. Both these airlines push security on several fronts:

Tough baggage checks. Security experts acknowledge that the latest weaponry -- handguns and cartridges made entirely from plastic, as well as plastic explosives molded into odorless sheets -- can elude normal baggage-screening devices.

Some explosives can be assembled fairly easily from readily available chemicals. Police intelligence officers interviewed last month in Northern Ireland estimate that 80 percent of the terrorist bombs used there are made from agricultural fertilizer, which can be made to explode because of its high nitrogen content.

To prevent in-air explosions, say security experts, airlines will need to use a combination of measures in addition to the usual electronic screening measures. These include searches of carry-on luggage and body searches of passengers, plus sweeps of planes between flights by trained personnel.

Officials may also need to reexamine luggage checked through from prior airports -- especially from countries where security is thought to be lax.

El Al reportedly passes all its checked luggage through a pressure chamber that simulates a flight at 30,000 feet -- thereby detonating any pressure-sensitive suitcase bombs before they board the plane.

Better intelligence concerning passengers. Airlines are increasingly interested in knowing who is flying and why.

Emphasizing the importance of such an approach, Wilkinson points to the need for ``much tighter security checks on passengers.'' He says: ``There must be no question of anybody getting anything past [security officials] onto the flight.'' Such checks should also prevent passengers from checking baggage onto a flight and then leaving the plane, and passengers from carrying on packages given to them by strangers or unknowingly hidden in their luggage.

Tighter control over access to planes on the ground. In many airports, planes sometimes sit empty for hours in loosely guarded holding areas.

In some places, says Wilkinson, ``Anyone with a uniform on will be allowed to come out onto the airstrip.'' Improved background security checks on airline employees as well as a much tougher system of checking identification is needed.

``You just have to restrict absolutely the number of people who get out there onto the airport,'' says McGeorge. He cites a bomb search of a domestic plane following a tip in the 1970s. The bomb was in the first-aid kit in the cockpit -- obviously placed by an ``insider'' rather than a passenger.

Some airports have taken strong steps in this direction. Travelers arriving at Belfast airport at night, for example, notice that the entire runway is surrounded by high chain-link fence illuminated by bright lights.

What effect will such controls have on passengers? ``I think passengers are going to demand them,'' says Wilkinson. He notes that El Al, despite time-consuming procedures, continues to be profitable.