Narrative:

We were cleared for the ILS runway 35L during significant WX at the airfield. When we were about at the FAF; ATC offered us runway 36R. Since that was further away from the storms near the airfield; we accepted it. I then tried to switch the runway in the mcdu. However; in the process of doing so (runway change with no SID selected); it didn't switch all the way. Part of the old approach (35L) remained with all of the new one. And the old wouldn't clear out. This lead me to become 'heads down' as we got lower on the approach. It wasn't until ATC told us that we were still on runway 35L did we realize that we hadn't moved over the west runways. (The localizer still showed centered; but it was still for runway 35L.) we executed a go around and got vectored to runway 36R.

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Original NASA ASRS Text

Title: DIFFICULTY PROGRAMMING FMS IN RESPONSE TO A LATE RWY CHANGE PREDICATED ON PROXIMITY OF WX; FLT CREW OF A319 EXECUTES GAR AND STARTS OVER.

Narrative: WE WERE CLRED FOR THE ILS RWY 35L DURING SIGNIFICANT WX AT THE AIRFIELD. WHEN WE WERE ABOUT AT THE FAF; ATC OFFERED US RWY 36R. SINCE THAT WAS FURTHER AWAY FROM THE STORMS NEAR THE AIRFIELD; WE ACCEPTED IT. I THEN TRIED TO SWITCH THE RWY IN THE MCDU. HOWEVER; IN THE PROCESS OF DOING SO (RWY CHANGE WITH NO SID SELECTED); IT DIDN'T SWITCH ALL THE WAY. PART OF THE OLD APCH (35L) REMAINED WITH ALL OF THE NEW ONE. AND THE OLD WOULDN'T CLR OUT. THIS LEAD ME TO BECOME 'HEADS DOWN' AS WE GOT LOWER ON THE APCH. IT WASN'T UNTIL ATC TOLD US THAT WE WERE STILL ON RWY 35L DID WE REALIZE THAT WE HADN'T MOVED OVER THE W RWYS. (THE LOC STILL SHOWED CTRED; BUT IT WAS STILL FOR RWY 35L.) WE EXECUTED A GAR AND GOT VECTORED TO RWY 36R.

Data retrieved from NASA's ASRS site as of May 2009 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.