The nation's airlines, beset by terrorist attacks, are doing their best to convince passengers that security measures -- for their own protection -- are being beefed up.

Pan American Airways has even taken the bold step of establishing a new subsidiary, Alert Management Services, to operate its own protection and inspection system, instead of contracting outside guards. And in its advertising, Pan Am is publicizing the steps it is taking, hoping to restore passenger confidence. In the old days, of course, airlines shunned any reference to the hazards of flying -- whether from terrorists, or unsafe aircraft or procedures.

But after going through Dulles here, Heathrow in London and Zurich International Airport within the past two weeks, I doubt that the new security measures live up to their billing.

My experience taken alone, of course, does not qualify as an adequate sample. But a check with a dozen colleagues who have traveled all over the country and in Canada indicates few significant changes in observable procedures.

The only exceptions these Washington Post reporters have spotted are occasional closer inspections of hand luggage at the shuttle terminal at LaGuardia Airport in New York, and the requirement at some National Airport gates in Washington and in Syracuse, N.Y., that tickets be shown before putting luggage on the X-ray conveyor belt.

This is not to say that the airlines are not trying other strategies and improved technologies to counteract terrorism. Pan Am, for example, has hired as consultants employes of Israel's El Al national airline, known for its tough security checks of passengers and luggage.

Pan Am contends that the quality of its security personnel will improve and that many safety measures now being provided are subtle, and therefore not necessarily obvious to passengers.

"Our intelligence is better than it was a month ago," Pan Am security chief Fred Ford told me. Over the July Fourth weekend in New York, Pan Am followed up on a tip and installed a security check at its Manhattan heliport. Normally, the basic security check occurs after the helicopter flight to J. F. Kennedy International Airport in Queens.

Ford said that Pan Am's new security staff at three principal American gateways -- Washington, New York and Miami -- are backstopping the procedures followed by the airport authorities. "Our people are watching, and even though you get by the government people, you may not satisfy Pan Am," Ford said.

He cites the case of a Pan Am flight from Charles deGaulle Airport in Paris to New York last week that was held up for 75 minutes when two passengers who had checked luggage did not board. The crew noted the empty seats, and were about to have the others disembark to identify and claim their luggage, when the two missing passengers -- who had not heard the final call for the flight -- showed up. If they hadn't, Ford said, their luggage would have been deboarded.

Nonetheless, my colleagues and I suspect that much of what we are told about improved security is a noble goal, as yet unrealized, and exaggerated for public relations. There seems, for example, to be little real difference in the X-ray checking procedure for hand luggage.

At Dulles, Heathrow and Zurich's airports, I didn't see a single bag taken off the X-ray conveyor for a hand-inspection. Colleagues traveling to and from Washington National Airport, Boston, Dulles, Dallas, Minneapolis, Los Angeles, Miami and Toronto in the past week confirmed that most procedures continue to be quite casual.

At Heathrow during a routine hand inspection of carry-on luggage in the boarding lounge for Pan Am's Flight 107 to Washington on July 2, an over-eager inspector had me remove four batteries from a portable computer, while a friend passed through totally unchecked. Ford told me when I asked about the battery removal that the inspector had probably misunderstood instructions relating to potential triggering mechanisms for explosives. In any real question about such a triggering device, a supervisor should have been called; at Heathrow, the agent put the batteries back in my bag.

It seems clear that the airlines have barely scratched the surface in training their personnel in what to look for, and what to do when they have suspicions. Most important, security people need to ask questions, Israeli-style.

When El Al foiled a plot recently in London in which a woman unknowingly was carrying a specially rigged pocket calculator designed to explode a plastic bomb, they succeeded because of their well-devised grilling routine: How many days did she plan to stay in Tel Aviv? Did she have friends there? If not, where did she plan to stay? How much money did she have?

When she said it would be 10 days at the Tel Aviv Hilton, but said she only had 50 British pounds (which couldn't cover more than a single day), the agents got suspicious.

Enhanced security will cost the airlines money, and passengers will pay the freight. I can't imagine anyone who will object to the higher fares that will result. All seasoned travelers also understand that there can be no absolute guarantee of their safety. But a false sense of security can be created if the new procedures don't live up to the way they're being hyped.