Narrative:

Went to dispatch to pick up flight release. Found release for a phx-pdx flight (my route). Signed release, went to aircraft. Completed preflight actions and departed for pdx. After departure, I called times back to operations, using the flight number off the release. I then realized that that was not 'our' flight number. Checking the paperwork more closely, I found I had picked up a release for an A319 flight from phx to pdx, and we were in an A320. I didn't realize the mixup because 1) the route was correct. The weights, fuel load, speeds, passenger load were what we were expecting -- or close enough not to make us suspicious. 2) the release I picked up was for a flight that had departed 2 hours earlier than ours, but for some reason the paperwork was still available for me to pick up in dispatch. 3) I neglected to xchk the aircraft on the flight release with the aircraft I was in, as I usually do.

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Original NASA ASRS Text

Title: LGT CAPT PICKS UP A FLT RELEASE BY MISTAKE FOR ANOTHER COMPANY ACFT GOING TO THE SAME DEST VIA THE SAME ROUTING WITH A SIMILAR MODEL ACFT.

Narrative: WENT TO DISPATCH TO PICK UP FLT RELEASE. FOUND RELEASE FOR A PHX-PDX FLT (MY RTE). SIGNED RELEASE, WENT TO ACFT. COMPLETED PREFLT ACTIONS AND DEPARTED FOR PDX. AFTER DEP, I CALLED TIMES BACK TO OPS, USING THE FLT NUMBER OFF THE RELEASE. I THEN REALIZED THAT THAT WAS NOT 'OUR' FLT NUMBER. CHKING THE PAPERWORK MORE CLOSELY, I FOUND I HAD PICKED UP A RELEASE FOR AN A319 FLT FROM PHX TO PDX, AND WE WERE IN AN A320. I DIDN'T REALIZE THE MIXUP BECAUSE 1) THE RTE WAS CORRECT. THE WTS, FUEL LOAD, SPDS, PAX LOAD WERE WHAT WE WERE EXPECTING -- OR CLOSE ENOUGH NOT TO MAKE US SUSPICIOUS. 2) THE RELEASE I PICKED UP WAS FOR A FLT THAT HAD DEPARTED 2 HRS EARLIER THAN OURS, BUT FOR SOME REASON THE PAPERWORK WAS STILL AVAILABLE FOR ME TO PICK UP IN DISPATCH. 3) I NEGLECTED TO XCHK THE ACFT ON THE FLT RELEASE WITH THE ACFT I WAS IN, AS I USUALLY DO.

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.