Narrative:

We departed north las vegas and were assigned heading 220 degrees and 4000 ft. After we contacted approach he cleared us into class B at 4000 ft (we were planning on departing the area to the south). When he cleared us into class B at 4000 ft, for some reason I assumed own navigation. No reference was made toward maintaining our current heading. We had rising terrain ahead of us and I instructed the owner to fly on course. About 1 min later, las approach asked if we were still heading 220 degrees. I responded no, and that we were heading 154(?) degrees on course. I apologized and said we'll turn back. He said too late and revectored us. He was very nice about it. I fly into sfo class B several times a week and am diligent about following vectors, altitudes, etc. This time, I let the terrain (my fear of it) allow myself to misinterpret the controller's instructions. The owner is also a low time pilot in an advanced single who has trouble staying ahead of the plane and I let his nervousness question what we were doing. Alone, I most likely would not have done this (therefore, pressure to perform and act professional).

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Original NASA ASRS Text

Title: DURING A TRAINING FLT IN A MOONEY M20-M THE INSTRUCTOR DIRECTED THE STUDENT TO TURN BACK TO THE DEPARTING HDG RATHER THAN MAINTAINING THE ASSIGNED VECTOR HDG. ATC INTERVENED AND REDIRECTED THEM ON COURSE.

Narrative: WE DEPARTED N LAS VEGAS AND WERE ASSIGNED HDG 220 DEGS AND 4000 FT. AFTER WE CONTACTED APCH HE CLRED US INTO CLASS B AT 4000 FT (WE WERE PLANNING ON DEPARTING THE AREA TO THE S). WHEN HE CLRED US INTO CLASS B AT 4000 FT, FOR SOME REASON I ASSUMED OWN NAV. NO REF WAS MADE TOWARD MAINTAINING OUR CURRENT HDG. WE HAD RISING TERRAIN AHEAD OF US AND I INSTRUCTED THE OWNER TO FLY ON COURSE. ABOUT 1 MIN LATER, LAS APCH ASKED IF WE WERE STILL HDG 220 DEGS. I RESPONDED NO, AND THAT WE WERE HDG 154(?) DEGS ON COURSE. I APOLOGIZED AND SAID WE'LL TURN BACK. HE SAID TOO LATE AND REVECTORED US. HE WAS VERY NICE ABOUT IT. I FLY INTO SFO CLASS B SEVERAL TIMES A WK AND AM DILIGENT ABOUT FOLLOWING VECTORS, ALTS, ETC. THIS TIME, I LET THE TERRAIN (MY FEAR OF IT) ALLOW MYSELF TO MISINTERPRET THE CTLR'S INSTRUCTIONS. THE OWNER IS ALSO A LOW TIME PLT IN AN ADVANCED SINGLE WHO HAS TROUBLE STAYING AHEAD OF THE PLANE AND I LET HIS NERVOUSNESS QUESTION WHAT WE WERE DOING. ALONE, I MOST LIKELY WOULD NOT HAVE DONE THIS (THEREFORE, PRESSURE TO PERFORM AND ACT PROFESSIONAL).

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.