On December 14 1988, the following warning was publicly posted at the U.S. Embassy in Moscow.
American Embassy, Moscow
December 13, 1988
To: All Embassy Employees
Subject: Threat to Civil Aviation
Post has been notified by the Federal Aviation Administration that on December 5, 1988, an unidentified individual telephoned a U.S diplomatic facility in Europe and stated that sometime within the next two weeks there would be a bombing attempt against a Pan American aircraft flying from Frankfurt to the United States.
The FAA reports that the reliability of the information cannot be assessed at this point, but the appropriate police authorities have been notified and are pursuing the matter. Pan Am also has been notified.
In view of the lack of confirmation of this information, post leaves to the discretion of individual travelers any decisions on altering personal travel plans or changing to another American carrier. This does not absolve the traveler from flying an American carrier
William C. Kelly, Administrative Counselor