of being over the limit for alcohol before flying. abc s senior transportation correspondent david kerley with that story. reporter: british authorities detained the american airlines flight crew member in manchester before the a-330 took off for philadelphia. an aviation source telling abc news, it was one of the three pilots, but it is unclear if it was the captain or one of the first officers who tonight is being investigated for suspicion of performing an aviation function when over the prescribed limit of alcohol. american canceled that flight, rebooking passengers and saying in a statement, safety is our highest priority and we apologize to our customers. the limit for alcohol in pilots is half that for drivers, .04. this pilot arrested two years ago in detroit. and some like this former jetblue pilot faced federal charges. did you put 270 passengers at risk? no comment. this is an ongoing issue you ve reported on before. david kerley with us again tonight. we re aware