A Boeing 747 was forced to make an emergency landing at Mirabel airport during a test flight this morning after there was a problem with one of its engines shortly after take-off.

"As a precaution, the pilots decided to return to the airport and landed. There was no fire or emergency declared. On landing, no visual damage was apparent," said Nancy German, vice-president of communications at Pratt & Whitney Canada — the aerospace company which owns the aircraft.

There were no injuries.  All 14 people on board were members of the test crew. 

Emergency personnel met the aircraft as a precaution. 

Mirabel airport spokesman François Asselin says companies frequently test flights at Mirabel, and there are a couple dozen emergency landings at the airport each year.

Officials at Pratt & Whitney say it is still not known what caused the possible engine problem, but they are investigating the situation.