Narrative:

Our clearance out of phx was 'the dryheat 2' to dryheat J74-trw-tul, I entered this in the FMC an double-checked it with the filed route. Looking at the departure chart is where I made the mistake. Since we were given dryheat intersection in the clearance, this sounded like a departure transition. On the chart it depicts the 070 degree radial off of pxr to bayta, chopr, and so on. This radial coincides with the 075 degree heading off of runway 7L at 4 DME. The chart also shows a 100 degree heading vector at 4 DME as well. I mistakenly thought that the 100 degree vector was a separate transition and since we had been cleared to dryheat intersection, I intercepted the 070 degree radial and flew outbound. Departure questioned us at this point and then cleared us to bayta on course but asked us to call them. There were not any aircraft close by and we created no conflict. One other thing. Company had departed ahead of us and tower had given us the following: 'company ahead will be turning sbound, maintain visual with him, cleared for takeoff.' this reinforced my belief that we were going to be on different transitions and diverging at the 4 DME point. The blame is squarely on my shoulders for not thoroughly reading all of the textual procedure. I do, however, think the chart needs to be improved so that there is a more definite separation between the initial headings and the 070 degree radial. If there was more of a break on the chart there would have been no confusion on my part.

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Original NASA ASRS Text

Title: FLC MISINTERPRETED A DEP SID AND FAILED TO MAKE A REQUIRED TURN.

Narrative: OUR CLRNC OUT OF PHX WAS 'THE DRYHEAT 2' TO DRYHEAT J74-TRW-TUL, I ENTERED THIS IN THE FMC AN DOUBLE-CHKED IT WITH THE FILED RTE. LOOKING AT THE DEP CHART IS WHERE I MADE THE MISTAKE. SINCE WE WERE GIVEN DRYHEAT INTXN IN THE CLRNC, THIS SOUNDED LIKE A DEP TRANSITION. ON THE CHART IT DEPICTS THE 070 DEG RADIAL OFF OF PXR TO BAYTA, CHOPR, AND SO ON. THIS RADIAL COINCIDES WITH THE 075 DEG HDG OFF OF RWY 7L AT 4 DME. THE CHART ALSO SHOWS A 100 DEG HDG VECTOR AT 4 DME AS WELL. I MISTAKENLY THOUGHT THAT THE 100 DEG VECTOR WAS A SEPARATE TRANSITION AND SINCE WE HAD BEEN CLRED TO DRYHEAT INTXN, I INTERCEPTED THE 070 DEG RADIAL AND FLEW OUTBOUND. DEP QUESTIONED US AT THIS POINT AND THEN CLRED US TO BAYTA ON COURSE BUT ASKED US TO CALL THEM. THERE WERE NOT ANY ACFT CLOSE BY AND WE CREATED NO CONFLICT. ONE OTHER THING. COMPANY HAD DEPARTED AHEAD OF US AND TWR HAD GIVEN US THE FOLLOWING: 'COMPANY AHEAD WILL BE TURNING SBOUND, MAINTAIN VISUAL WITH HIM, CLRED FOR TKOF.' THIS REINFORCED MY BELIEF THAT WE WERE GOING TO BE ON DIFFERENT TRANSITIONS AND DIVERGING AT THE 4 DME POINT. THE BLAME IS SQUARELY ON MY SHOULDERS FOR NOT THOROUGHLY READING ALL OF THE TEXTUAL PROC. I DO, HOWEVER, THINK THE CHART NEEDS TO BE IMPROVED SO THAT THERE IS A MORE DEFINITE SEPARATION BTWN THE INITIAL HEADINGS AND THE 070 DEG RADIAL. IF THERE WAS MORE OF A BREAK ON THE CHART THERE WOULD HAVE BEEN NO CONFUSION ON MY PART.

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.