Narrative:

Pre departure clearance stated kennedy 6 departure, initial heading 205 degrees maintain 5000 ft. Pushed back and taxied to runway 31L. We were in a long line for takeoff. Prior to takeoff, each aircraft was given an initial heading or fix. After we were cleared into position to hold, I expected to be given a heading or fix if ATC wanted something different from the pre departure clearance. We were cleared for takeoff with no further instructions. At about 2500 ft and heading 205 degrees, ATC asked what our heading was. We told them 205 degree assigned. They immediately restr us to 3000 ft and turned us to heading 050 degrees. There was an aircraft crossing in front of us at approximately 4000 ft. When we pursued the matter of heading, we were told that the runway had changed and therefore the heading changed also. The pre departure clearance says nothing about the initial heading being tied to a specific runway and we had no way to know which runway they intended to use. Since they should have known of the runway change and therefore our incorrect heading assignment, tower should have given us correct instructions prior to takeoff. Had departure been busy and missed the traffic conflict a near miss or a midair collision could have resulted. We could have questioned tower prior to takeoff but since they had informed other flts of desired heading I presumed that we were to proceed as cleared. Perhaps initial headings on the pre departure clearance need to be paired with the intended takeoff runway.

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Original NASA ASRS Text

Title: ACR X WRONG PDC HDG AFTER DEP.

Narrative: PDC STATED KENNEDY 6 DEP, INITIAL HDG 205 DEGS MAINTAIN 5000 FT. PUSHED BACK AND TAXIED TO RWY 31L. WE WERE IN A LONG LINE FOR TKOF. PRIOR TO TKOF, EACH ACFT WAS GIVEN AN INITIAL HDG OR FIX. AFTER WE WERE CLRED INTO POS TO HOLD, I EXPECTED TO BE GIVEN A HDG OR FIX IF ATC WANTED SOMETHING DIFFERENT FROM THE PDC. WE WERE CLRED FOR TKOF WITH NO FURTHER INSTRUCTIONS. AT ABOUT 2500 FT AND HDG 205 DEGS, ATC ASKED WHAT OUR HDG WAS. WE TOLD THEM 205 DEG ASSIGNED. THEY IMMEDIATELY RESTR US TO 3000 FT AND TURNED US TO HDG 050 DEGS. THERE WAS AN ACFT XING IN FRONT OF US AT APPROX 4000 FT. WHEN WE PURSUED THE MATTER OF HDG, WE WERE TOLD THAT THE RWY HAD CHANGED AND THEREFORE THE HDG CHANGED ALSO. THE PDC SAYS NOTHING ABOUT THE INITIAL HDG BEING TIED TO A SPECIFIC RWY AND WE HAD NO WAY TO KNOW WHICH RWY THEY INTENDED TO USE. SINCE THEY SHOULD HAVE KNOWN OF THE RWY CHANGE AND THEREFORE OUR INCORRECT HDG ASSIGNMENT, TWR SHOULD HAVE GIVEN US CORRECT INSTRUCTIONS PRIOR TO TKOF. HAD DEP BEEN BUSY AND MISSED THE TFC CONFLICT A NEAR MISS OR A MIDAIR COLLISION COULD HAVE RESULTED. WE COULD HAVE QUESTIONED TWR PRIOR TO TKOF BUT SINCE THEY HAD INFORMED OTHER FLTS OF DESIRED HDG I PRESUMED THAT WE WERE TO PROCEED AS CLRED. PERHAPS INITIAL HDGS ON THE PDC NEED TO BE PAIRED WITH THE INTENDED TKOF RWY.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.