WORLD : Radio-Cassette Hid Flight 103 Bomb

LOCKERBIE, Scotland — The bomb that blew up Pan Am Flight 103 on Dec. 21 was planted in a radio-cassette player and was probably loaded on the plane in Frankfurt, West Germany, the detective heading the investigation said today.

Chief Supt. John Orr refused to describe the size of the recorder, and he said it is not certain that the bomb was put aboard in Frankfurt, where the flight originated. But answering reporters’ questions, he said “the balance of probabilities” points to Frankfurt rather than London, where the New York-bound flight changed jets and took on new passengers. All 259 people on board the plane and 11 people on the ground were killed when the Boeing 747 exploded over Lockerbie.