AAL Flight 648 from SFO to PHL landed normally and was then directed to a remote area of the airport because of a bomb threat that was phoned into the FAA. The crew knew nothing about the threat until told by the tower after landing. A search of the aircraft and luggage proved negative.
This is the press release “Police met U.S. Airways flight 648, with 88 passengers and five crew on board, when it landed at Philadelphia International Airport due to a “possible security threat,” said Victoria Lupica, a spokeswoman for U.S. Airways’ parent company, American Airlines Group Inc
A possible bomb threat prompted the search, Philadelphia’s 6ABC television reported. No explosives were found”