Narrative:

Talking with salt lake approach control, PNF misunderstood clearance and readback 'cross 14 out at 8000 ft.' we both understood that to mean cross 14 DME out of salt lake city international at 8000 ft. We were not questioned on the incorrect readback and therefore descended to 7100 ft before being questioned by approach control. Apparently approach had said cross 14 DME south of the ogden VOR at 8000 ft. There was no conflict, and we were told by approach that there was no problem. If we had been questioned or we had been given a distance from the airport (since we were cleared for the approach and at that point it is most common to have distances referenced from the airport of intended landing) this may not have occurred. We were actually 900 ft low at the distance specified by approach. Supplemental information from acn 307774: we were setting up for landing when we received the clearance (first officer flying) and I did not hear all the clearance and did not hear 'ogden.' I was unfamiliar with this arrival and assumed he said 'salt lake VOR.' for confirmation I read back '14 out at or above 8 -- cleared visibility 16' and he said roger. I explained we misunderstood the clearance and we never heard 'ogden.' I called on the ground and he said there had been no traffic, no conflict. I never read the clearance back correctly but he assumed I was familiar.

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Original NASA ASRS Text

Title: ALTDEV ALT EXCURSION. NON ADHERENCE TO ATC CLRNC INSTRUCTION. ALT XING RESTR NOT MET.

Narrative: TALKING WITH SALT LAKE APCH CTL, PNF MISUNDERSTOOD CLRNC AND READBACK 'CROSS 14 OUT AT 8000 FT.' WE BOTH UNDERSTOOD THAT TO MEAN CROSS 14 DME OUT OF SALT LAKE CITY INTL AT 8000 FT. WE WERE NOT QUESTIONED ON THE INCORRECT READBACK AND THEREFORE DSNDED TO 7100 FT BEFORE BEING QUESTIONED BY APCH CTL. APPARENTLY APCH HAD SAID CROSS 14 DME S OF THE OGDEN VOR AT 8000 FT. THERE WAS NO CONFLICT, AND WE WERE TOLD BY APCH THAT THERE WAS NO PROB. IF WE HAD BEEN QUESTIONED OR WE HAD BEEN GIVEN A DISTANCE FROM THE ARPT (SINCE WE WERE CLRED FOR THE APCH AND AT THAT POINT IT IS MOST COMMON TO HAVE DISTANCES REFED FROM THE ARPT OF INTENDED LNDG) THIS MAY NOT HAVE OCCURRED. WE WERE ACTUALLY 900 FT LOW AT THE DISTANCE SPECIFIED BY APCH. SUPPLEMENTAL INFO FROM ACN 307774: WE WERE SETTING UP FOR LNDG WHEN WE RECEIVED THE CLRNC (FO FLYING) AND I DID NOT HEAR ALL THE CLRNC AND DID NOT HEAR 'OGDEN.' I WAS UNFAMILIAR WITH THIS ARR AND ASSUMED HE SAID 'SALT LAKE VOR.' FOR CONFIRMATION I READ BACK '14 OUT AT OR ABOVE 8 -- CLRED VISIBILITY 16' AND HE SAID ROGER. I EXPLAINED WE MISUNDERSTOOD THE CLRNC AND WE NEVER HEARD 'OGDEN.' I CALLED ON THE GND AND HE SAID THERE HAD BEEN NO TFC, NO CONFLICT. I NEVER READ THE CLRNC BACK CORRECTLY BUT HE ASSUMED I WAS FAMILIAR.

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.