bomb threat that forced a United Airlines flight bound for Los Angeles to return to Sydney was caused by a note scrawled on a sick bag and was definitely a hoax, officials said on Wednesday.
United flight 840, carrying 246 passengers including a senior US diplomat, returned to Sydney about 90 minutes after take-off on Tuesday.
"I'm quite confident that after all the risk assessment that was conducted by United Airlines, New South Wales Police and the Australian Federal Police that this is in fact a hoax," police superintendent Peter O'Brien told reporters.
Transport officials have so far refused to confirm the contents of the note but ABC (Australian Broadcasting Corporation) radio said on Wednesday that an air sickness bag with the letters "B O B" scrawled on it had been found in a toilet on board.
The pilot decided the note could have meant "bomb on board" and returned to Sydney, dumping almost a full load of fuel before the Boeing 747-400 landed safely.
Several other possibilities were being investigated, including that the note could have been a popular flight crew acronym for a good looking passenger, or simply a man named Bob.
Flight attendants said crews sometimes use "BOB" to refer to "best on board", or the most attractive passengers on the plane.
