Medium Large Transport
Air Traffic Control Fully Certified
Air Traffic Control Time Certified In Pos 1 (yrs) 2
Situational Awareness; Workload; Communication Breakdown; Distraction
ATC Issue All Types; Conflict Airborne Conflict; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Published Material / Policy; Deviation / Discrepancy - Procedural Clearance; Ground Incursion Runway
Air Traffic Control Issued New Clearance; Flight Crew Returned To Clearance
Human Factors; Procedure
Aircraft X was in position on runway 8; Aircraft Y was in position on runway 9L. I told another aircraft to cross runway 9L at D hold short of runway 8. Then I cleared Aircraft X for takeoff on runway 8. Aircraft Y read cleared for takeoff runway 8. I stepped on Aircraft X; when telling another aircraft to hold short of taxiway A. Aircraft X called again saying they were cleared for takeoff on Runway 8 and I said affirmative. Then looked at 9L and saw Aircraft Y already rolling and almost airborne. Once he was airborne; I provided the visual separation and told him to fly runway heading and then I turned Aircraft X to 050 heading. I should have listened for the bad readback.
We were issued line up and wait runway 9L. Then; we were given 'Aircraft Y heading 050 cleared for takeoff 9L'. During upwind climb we received 'fly runway heading'. After some thought; having a 050 heading changed just after takeoff to runway heading; we found it odd. We thought this could possibly be a misheard clearance; or a wrong clearance given by tower. Later discussing the event we determined it was odd to receive 050 heading from runway 9L followed by a quick change to runway heading. Possible misheard clearance or tower issued the wrong clearance.Listen closer and confirm instructions.
PHL Tower Controller and a First Officer involved reported the First Officer took another aircraft's takeoff clearance.