Narrative:

Approaching phx from the northeast, we were told by approach control to identify the traffic we were to follow for a visual approach. Spotting the aircraft that I felt met the description the controller had given, we called the aircraft in sight and were cleared for the visual approach runway 26L to follow the traffic we had idented. This was not the runway we had anticipated and our FMC was updated to reflect the runway change. As we neared the airport, I continued to maintain visual contact with the aircraft ahead of us and spacing seemed more than adequate. The controller then told us we were 40 KTS ground speed faster than the aircraft ahead of us. I slowed the aircraft and shortly thereafter the captain saw traffic at our left moving to our 12 O'clock position turning final ahead of us. He immediately inquired with the controller and the controller said this was the aircraft we were to be following. Sensing that the spacing would be too tight, the controller turned us 90 degrees left and had us climb to 5000 ft (?) and had us vectored for another approach which occurred without further incident. In the future, I will take greater care when calling an aircraft in sight -- especially in an area where there can be multiple aircraft. Positive identify is a must! Additionally, knowing the runway which will actually be assigned at the earliest moment possible will keep an extra set of eyes outside the cockpit where they are often needed as opposed to making an FMC change inside the cockpit.

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Original NASA ASRS Text

Title: AN A320 CREW LOSES SPACING FOR LNDG WHEN FOLLOWING THE WRONG ACFT FOR A VISUAL APCH TO RWY 26L AT PHX, AZ.

Narrative: APCHING PHX FROM THE NE, WE WERE TOLD BY APCH CTL TO IDENT THE TFC WE WERE TO FOLLOW FOR A VISUAL APCH. SPOTTING THE ACFT THAT I FELT MET THE DESCRIPTION THE CTLR HAD GIVEN, WE CALLED THE ACFT IN SIGHT AND WERE CLRED FOR THE VISUAL APCH RWY 26L TO FOLLOW THE TFC WE HAD IDENTED. THIS WAS NOT THE RWY WE HAD ANTICIPATED AND OUR FMC WAS UPDATED TO REFLECT THE RWY CHANGE. AS WE NEARED THE ARPT, I CONTINUED TO MAINTAIN VISUAL CONTACT WITH THE ACFT AHEAD OF US AND SPACING SEEMED MORE THAN ADEQUATE. THE CTLR THEN TOLD US WE WERE 40 KTS GND SPD FASTER THAN THE ACFT AHEAD OF US. I SLOWED THE ACFT AND SHORTLY THEREAFTER THE CAPT SAW TFC AT OUR L MOVING TO OUR 12 O'CLOCK POS TURNING FINAL AHEAD OF US. HE IMMEDIATELY INQUIRED WITH THE CTLR AND THE CTLR SAID THIS WAS THE ACFT WE WERE TO BE FOLLOWING. SENSING THAT THE SPACING WOULD BE TOO TIGHT, THE CTLR TURNED US 90 DEGS L AND HAD US CLB TO 5000 FT (?) AND HAD US VECTORED FOR ANOTHER APCH WHICH OCCURRED WITHOUT FURTHER INCIDENT. IN THE FUTURE, I WILL TAKE GREATER CARE WHEN CALLING AN ACFT IN SIGHT -- ESPECIALLY IN AN AREA WHERE THERE CAN BE MULTIPLE ACFT. POSITIVE IDENT IS A MUST! ADDITIONALLY, KNOWING THE RWY WHICH WILL ACTUALLY BE ASSIGNED AT THE EARLIEST MOMENT POSSIBLE WILL KEEP AN EXTRA SET OF EYES OUTSIDE THE COCKPIT WHERE THEY ARE OFTEN NEEDED AS OPPOSED TO MAKING AN FMC CHANGE INSIDE THE COCKPIT.

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.