Narrative:

When cleared for takeoff on runway 17R at dfw the tower stated '100 at 17 cleared for takeoff.' I read back 'left 100, cleared for takeoff runway 17R.' departure controller questioned our heading and said the tower did not give the 100 degree heading. The SID called for 174 degree heading which would have placed us in WX. We thought the 'turn' was to avoid thunderstorm cells. Apparently, what I misheard was the wind readout of '100 degrees at 17 KTS.' what I heard was: '1-0-0, 1-7 cleared for takeoff.' I thought he said '100 degree heading' and runway 17R cleared for takeoff. Callback conversation with reporter revealed the following information: crew was flying a DC9-30. Both crew members did not hear any reference to 'wind' mentioned. Since there were thunderstorms immediately south of the airport it seemed the thing to do was turn to avoid them. The clearance they thought did just that. The tower local controller did not correct the readback.

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Original NASA ASRS Text

Title: DC9 CREW HAD TRACK DEV DEPARTING DFW.

Narrative: WHEN CLRED FOR TKOF ON RWY 17R AT DFW THE TWR STATED '100 AT 17 CLRED FOR TKOF.' I READ BACK 'LEFT 100, CLRED FOR TKOF RWY 17R.' DEP CTLR QUESTIONED OUR HEADING AND SAID THE TWR DID NOT GIVE THE 100 DEG HDG. THE SID CALLED FOR 174 DEG HDG WHICH WOULD HAVE PLACED US IN WX. WE THOUGHT THE 'TURN' WAS TO AVOID TSTM CELLS. APPARENTLY, WHAT I MISHEARD WAS THE WIND READOUT OF '100 DEGS AT 17 KTS.' WHAT I HEARD WAS: '1-0-0, 1-7 CLRED FOR TKOF.' I THOUGHT HE SAID '100 DEG HDG' AND RWY 17R CLRED FOR TKOF. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: CREW WAS FLYING A DC9-30. BOTH CREW MEMBERS DID NOT HEAR ANY REF TO 'WIND' MENTIONED. SINCE THERE WERE TSTMS IMMEDIATELY S OF THE ARPT IT SEEMED THE THING TO DO WAS TURN TO AVOID THEM. THE CLRNC THEY THOUGHT DID JUST THAT. THE TWR LCL CTLR DID NOT CORRECT THE READBACK.

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.