Narrative:

We were on a flight from pdx to rdd. About 15 mins out of pdx we were cleared direct rdd. North of mt shasta, ZSE gave us pilot's discretion to 7000 ft. We read back the clearance. A few mins later we asked direct milar for the localizer back course approach into redding and stated our altitude that we were descending out of and descending to. She stated that the next center would give us that clearance. We contacted ZOA and called out of 14500 ft descending to 7000 ft. ZOA said, 'confirm you're descending to 17000 ft, what's your present altitude?' we stated, '14500 ft.' ZOA then said, 'do you have the terrain in sight?' we said yes and that we were VMC. Center then said maintain 11000 ft. 1) we both later discussed if we could have misinterped 17000 ft for 7000 ft. We definitely both heard 7000 ft and read back 7000 ft, twice, to ZSE. 2) it was VMC, we could see our flight path took us over lower terrain to the west of mt shasta. Our FMS confirmed it. 3) the reasons we did not challenge the 7000 ft altitude: we read back the assignment twice. We both agreed we heard 7000 ft. We were VMC and could see our flight path took us over lower terrain.

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Original NASA ASRS Text

Title: ATC CLRED DH8 TO DSND TO 17000 FT. FLT CREW HEARD DSND TO 7000 FT. CTLR MISSED INCORRECT READBACK.

Narrative: WE WERE ON A FLT FROM PDX TO RDD. ABOUT 15 MINS OUT OF PDX WE WERE CLRED DIRECT RDD. N OF MT SHASTA, ZSE GAVE US PLT'S DISCRETION TO 7000 FT. WE READ BACK THE CLRNC. A FEW MINS LATER WE ASKED DIRECT MILAR FOR THE LOC BACK COURSE APCH INTO REDDING AND STATED OUR ALT THAT WE WERE DSNDING OUT OF AND DSNDING TO. SHE STATED THAT THE NEXT CTR WOULD GIVE US THAT CLRNC. WE CONTACTED ZOA AND CALLED OUT OF 14500 FT DSNDING TO 7000 FT. ZOA SAID, 'CONFIRM YOU'RE DSNDING TO 17000 FT, WHAT'S YOUR PRESENT ALT?' WE STATED, '14500 FT.' ZOA THEN SAID, 'DO YOU HAVE THE TERRAIN IN SIGHT?' WE SAID YES AND THAT WE WERE VMC. CTR THEN SAID MAINTAIN 11000 FT. 1) WE BOTH LATER DISCUSSED IF WE COULD HAVE MISINTERPED 17000 FT FOR 7000 FT. WE DEFINITELY BOTH HEARD 7000 FT AND READ BACK 7000 FT, TWICE, TO ZSE. 2) IT WAS VMC, WE COULD SEE OUR FLT PATH TOOK US OVER LOWER TERRAIN TO THE W OF MT SHASTA. OUR FMS CONFIRMED IT. 3) THE REASONS WE DID NOT CHALLENGE THE 7000 FT ALT: WE READ BACK THE ASSIGNMENT TWICE. WE BOTH AGREED WE HEARD 7000 FT. WE WERE VMC AND COULD SEE OUR FLT PATH TOOK US OVER LOWER TERRAIN.

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.