Narrative:

ZLC cleared our flight direct to salt lake city about 400 NM out. I read back the clearance. I observed (in the large scale navigation display) that the 'direct to salt lake' course took us through the originally filed arrival, the SPANE4. Seeing how close it was to the 'direct to salt lake' and wanting to preserve the managed descent profile, I selected the point of spane on the arrival as the direct to point. Having done this flight a couple of times, I was confident that we were supposed to, and or were expected, to do the spane 4 arrival anyway because of the terrain. In this confidence, or perhaps complacency, I did not seek clarification. In the last of an 8 hour flight day and early in the morning there may have been an element of fatigue in this decision. 200 NM out ZLC called and asked us about a 15 degree course error in our 'direct to salt lake city' clearance. We adjusted our course immediately and advised center we had made the correction and nothing else was said. I don't know how I convinced myself that the arrival was required. I am always a little nervous about the high terrain and the night, having lost friends to both and perhaps I overcompensated. I remember thinking they said, 'direct to slc' but they meant 'direct to, via the arrival.' on the spane 4 arrival, spane is 42 NM south of salt lake and as we neared slc, the angular difference in our course increased. I was aware that we could have inserted an altitude over slc and used that for a managed descent. My hindsight has produced too many what if's and 'should of, could of, would of's' to list here. But, at the time, I was sure I had found an adequate solution to all the problems and did not properly assess the distance of spane away from slc. It won't happen again on my watch. Direct to means, direct to!

Google
 

Original NASA ASRS Text

Title: FLT CREW OF A320 MAKE THE ERRONEOUS ASSUMPTION THAT WHEN ZLC RADAR CLRED THEM DIRECT SLC THEY ACTUALLY INTENDED THEM TO FLY TO A FIX FROM WHICH THE STAR THEY HAD PREVIOUSLY ANTICIPATED BEGAN. ALERT CTLR CAUGHT THEIR TRACK DEV AND CORRECTED THEIR MISTAKEN ASSUMPTION.

Narrative: ZLC CLRED OUR FLT DIRECT TO SALT LAKE CITY ABOUT 400 NM OUT. I READ BACK THE CLRNC. I OBSERVED (IN THE LARGE SCALE NAV DISPLAY) THAT THE 'DIRECT TO SALT LAKE' COURSE TOOK US THROUGH THE ORIGINALLY FILED ARR, THE SPANE4. SEEING HOW CLOSE IT WAS TO THE 'DIRECT TO SALT LAKE' AND WANTING TO PRESERVE THE MANAGED DSCNT PROFILE, I SELECTED THE POINT OF SPANE ON THE ARR AS THE DIRECT TO POINT. HAVING DONE THIS FLT A COUPLE OF TIMES, I WAS CONFIDENT THAT WE WERE SUPPOSED TO, AND OR WERE EXPECTED, TO DO THE SPANE 4 ARR ANYWAY BECAUSE OF THE TERRAIN. IN THIS CONFIDENCE, OR PERHAPS COMPLACENCY, I DID NOT SEEK CLARIFICATION. IN THE LAST OF AN 8 HR FLT DAY AND EARLY IN THE MORNING THERE MAY HAVE BEEN AN ELEMENT OF FATIGUE IN THIS DECISION. 200 NM OUT ZLC CALLED AND ASKED US ABOUT A 15 DEG COURSE ERROR IN OUR 'DIRECT TO SALT LAKE CITY' CLRNC. WE ADJUSTED OUR COURSE IMMEDIATELY AND ADVISED CTR WE HAD MADE THE CORRECTION AND NOTHING ELSE WAS SAID. I DON'T KNOW HOW I CONVINCED MYSELF THAT THE ARR WAS REQUIRED. I AM ALWAYS A LITTLE NERVOUS ABOUT THE HIGH TERRAIN AND THE NIGHT, HAVING LOST FRIENDS TO BOTH AND PERHAPS I OVERCOMPENSATED. I REMEMBER THINKING THEY SAID, 'DIRECT TO SLC' BUT THEY MEANT 'DIRECT TO, VIA THE ARR.' ON THE SPANE 4 ARR, SPANE IS 42 NM S OF SALT LAKE AND AS WE NEARED SLC, THE ANGULAR DIFFERENCE IN OUR COURSE INCREASED. I WAS AWARE THAT WE COULD HAVE INSERTED AN ALT OVER SLC AND USED THAT FOR A MANAGED DSCNT. MY HINDSIGHT HAS PRODUCED TOO MANY WHAT IF'S AND 'SHOULD OF, COULD OF, WOULD OF'S' TO LIST HERE. BUT, AT THE TIME, I WAS SURE I HAD FOUND AN ADEQUATE SOLUTION TO ALL THE PROBS AND DID NOT PROPERLY ASSESS THE DISTANCE OF SPANE AWAY FROM SLC. IT WON'T HAPPEN AGAIN ON MY WATCH. DIRECT TO MEANS, DIRECT TO!

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.