Narrative:

Reference jackson, wy VOR DME runway 26 approach. We were holding on the jac 186 degree right at 16 DME southeast, right turns at 15000'. ZLC told us we were cleared for the approach on our next turn inbound and that we were cleared to change to advisory frequency. Turning inbound at above 21 or 22 DME we started to descend to try to cross the 16 DME fix at 11500'. I didn't feel right about this, although I wasn't sure why, but we were in VFR conditions at that altitude, so I didn't say anything. We continued the approach, although it was very difficult to get down to each step-down altitude, even though we had slowed down very early. We broke out well above minimums and made a normal landing to the north. When we called center to cancel IFR they expressed concern about our early descent. Upon reviewing the approach, I realized that we had left our last assigned altitude before we were established on a segment of the approach. Our attention was so focused on trying to get down, we didn't consider what was outside the 16 DME. This approach is just about impossible to make if the 16 DME is crossed at 15000'. This was exaggerated by a 35 KT tailwind down through about 9000'. For this reason, in my opinion, this approach should not be attempted from straight in or on the 186 degree right. The next time we attempted this approach, we requested a vector to the 141 degree right 16 DME to join the arc. We crossed this fix at 15000' and descended on the arc to 11500' before joining the 186 degree right. This worked out much better. I feel that this should be recommended procedure, if not by a note on the approach plate itself, at least by our company. I plan to bring this up to the pilot's union safety committee and also a debrief to the flight department.

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Original NASA ASRS Text

Title: ACR MLG HOLDING ON JAC 186 DEGREE RADIAL AT 16 DME DESCENDS TOO LOW WHEN CLEARED FOR THE APCH.

Narrative: REF JACKSON, WY VOR DME RWY 26 APCH. WE WERE HOLDING ON THE JAC 186 DEG R AT 16 DME SE, RIGHT TURNS AT 15000'. ZLC TOLD US WE WERE CLRED FOR THE APCH ON OUR NEXT TURN INBND AND THAT WE WERE CLRED TO CHANGE TO ADVISORY FREQ. TURNING INBND AT ABOVE 21 OR 22 DME WE STARTED TO DSND TO TRY TO CROSS THE 16 DME FIX AT 11500'. I DIDN'T FEEL RIGHT ABOUT THIS, ALTHOUGH I WASN'T SURE WHY, BUT WE WERE IN VFR CONDITIONS AT THAT ALT, SO I DIDN'T SAY ANYTHING. WE CONTINUED THE APCH, ALTHOUGH IT WAS VERY DIFFICULT TO GET DOWN TO EACH STEP-DOWN ALT, EVEN THOUGH WE HAD SLOWED DOWN VERY EARLY. WE BROKE OUT WELL ABOVE MINIMUMS AND MADE A NORMAL LNDG TO THE N. WHEN WE CALLED CENTER TO CANCEL IFR THEY EXPRESSED CONCERN ABOUT OUR EARLY DSCNT. UPON REVIEWING THE APCH, I REALIZED THAT WE HAD LEFT OUR LAST ASSIGNED ALT BEFORE WE WERE ESTABLISHED ON A SEGMENT OF THE APCH. OUR ATTN WAS SO FOCUSED ON TRYING TO GET DOWN, WE DIDN'T CONSIDER WHAT WAS OUTSIDE THE 16 DME. THIS APCH IS JUST ABOUT IMPOSSIBLE TO MAKE IF THE 16 DME IS CROSSED AT 15000'. THIS WAS EXAGGERATED BY A 35 KT TAILWIND DOWN THROUGH ABOUT 9000'. FOR THIS REASON, IN MY OPINION, THIS APCH SHOULD NOT BE ATTEMPTED FROM STRAIGHT IN OR ON THE 186 DEG R. THE NEXT TIME WE ATTEMPTED THIS APCH, WE REQUESTED A VECTOR TO THE 141 DEG R 16 DME TO JOIN THE ARC. WE CROSSED THIS FIX AT 15000' AND DSNDED ON THE ARC TO 11500' BEFORE JOINING THE 186 DEG R. THIS WORKED OUT MUCH BETTER. I FEEL THAT THIS SHOULD BE RECOMMENDED PROC, IF NOT BY A NOTE ON THE APCH PLATE ITSELF, AT LEAST BY OUR COMPANY. I PLAN TO BRING THIS UP TO THE PLT'S UNION SAFETY COMMITTEE AND ALSO A DEBRIEF TO THE FLT DEPT.

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.