Until the bombing of Pan American World Airways Flight 103 over Lockerbie, Scotland, last December, few American travelers were aware that the government routinely alerts airlines to the possibility of such acts of terrorism.

The disclosures that official warnings preceded the Pan Am bombing, in which 270 people died, and subsequent press reports of other security bulletins discussing potential hijackings and bomb threats, have raised a demand among many travelers for access to the advisories.Such warnings are sent only to security officials at law enforcement agencies, airlines and airports.

But while the federal government operates services to answer consumer questions about traveling safely, none will tell a consumer anything very specific about terrorist threats and how to avoid them.

There are a number of unofficial sources you might ask about your own travel plans.

Some people who believe they are special targets of terrorists - usually the wealthy or political figures - hire security consultants.

Most large corporations, especially those with international offices, have their own security offices, and it is worth a call to headquarters to see if your company is giving advice to employees who travel.

Al Spivak, a spokesman for General Dynamics, one of the nation's biggest defense contractors, said the company retained a consultant who ranked areas of the world, and even particular airlines, for relative security.

He said that executives traveling on company business were encouraged to seek advice from the corporate security office.

But could an employee of General Dynamics call for advice before embarking for a trip, say, to the pyramids of Egypt?

After checking, Spivak said, "The answer to your question is, yes. Our security personnel will provide whatever information we have to an employee, whether traveling for personal reasons or on company business. We already have the information - it's no extra work. We care about their safety as employees, and as individuals."

The advice you get this way probably is not based on secret information.

Rather, it is likely to be based on judgments reached by combing through information that is available to any assiduous researcher.

Security officers at a growing number of companies are linked to a computerized data base prepared by the State Department's Overseas Security Advisory Council, an organization that seeks to distribute information that could assist in security for the overseas employees of American companies.

Because the department's computer phone lines are limited and special software is needed, individuals are not able to tap directly into this data base.

But when I recently spent some time operating the computer terminal at the State Department, I saw nothing pertaining to terrorist attacks on aviation.

Most of the facts in the system could be found simply by reading the newspapers.

Ralph F. Laurello, who runs the system, noted that the bulletins contain no advice or analysis.

They simply repeat what is publicly available about topics ranging from street crime to political unrest.

Because this raw intelligence can be interpreted in many ways, you will find that the advice given by one supposed expert could contradict what another one says.

For example, experts disagree whether it is safer to fly on U.S. airlines or foreign ones.

Some people believe that American companies are particular targets, but others point out that there have actually been more attacks against foreign airlines, and that American companies are subject to tight security regulations by the Federal Aviation Administration.

"As far as I know, there is no channel of information that is at all useful, other than what the government chooses to let out," said Ed Perkins, the editor of the monthly Consumer Reports Travel Letter.

"If you ask for advice, you will either get an honest answer, which is `I don't know,' or you will get baseless information and ethnic prejudices."

Security officials say precautions are taken when a specific flight is in danger, and that the government's warnings about threats rarely mention a specific flight in any case.

"We understand and appreciate the desire of many to publicize threats and let the public pick and choose as to which is applicable to their flight," said Transportation Secretary Samuel K. Skinner in a recent press conference.

"We disagree with the policy of releasing all threats, and believe it would be flatly at odds with a proper discharge of our responsibility to insure safety in the skies. Publication of all threats will undoubtedly increase the number of hoax threats. A security community and the public, accustomed to daily threat information, also will be less likely to pay attention to the specific, credible threat. Publication of threat information will also dry up valuable sources of intelligence."

If the U.S. government knows about a "specific and credible" threat to a particular flight, and no measures can be taken to prevent the act, the airline in question would be advised - or, in the case of a U.S. airline, required - to cancel the flight, Skinner said.

If the flight is not canceled, he said, the State Department would publicize the threat widely, through the press, embassies and the travel industry.

If your flight is delayed, you can ask the ticket agent whether it was for security reasons. Recently, some airlines have on occasion let passengers know if a delay was caused by a bomb scare.

The State Department does maintain a list of travel advisories for dissemination to the public, but these never include details about threats of terrorist actions.

The quickest way to hear these advisories is to call the department's Citizens Emergency Center at 202-647-5225.

By using a touch-tone phone, a caller can hear whether there are advisories issued for travel to a particular country, or more generally within a geographic region.

It will take a while to wend your way through the hotline's menu of recorded instructions and itemized lists of countries, which are repeated from the beginning if information on more than one country is needed.

And the information is rarely detailed.

In the Middle East region, for example, callers are advised to "avoid" traveling in the Israeli-occupied West Bank and Gaza, and to check with the U.S. Embassy before entering East Jerusalem, where the situation is "unpredictable."

And the travel advisory for Kuwait points out that while hostilities have ceased between Iran and Kuwait's neighbor and ally, Iraq, there is no formal peace agreement and "the potential for terrorist activity exists."

But the State Department's listings for Europe make no mention of a warning by the Federal Aviation Administration in March, and subsequently revealed by the British press, that said three Arabs were suspected of planning to hijack an American airliner somewhere in Europe.

Initial reports about that security bulletin had some details wrong - for example, the London press reported that the threat pertained to the Easter weekend.

To correct the record, the Federal Aviation Administration issued a statement noting that no specific airline, airport or time period was specified in its warning.

The aviation agency's own hot line, reached by a toll-free call at 800-255-1111, is set up to hear passenger's complaints about safety violations by airlines, not to provide information about terrorist threats.

But if callers ask about threats they will be read a long statement, most of which explains why the agency will give no specific information about terrorist threats.

The statement says: "Travelers on U.S. air carriers should be confident that all reasonable precautions are being taken to insure that the highest level of security exists."