First officer reports missing crossing restr at grnpa on the arrival to las after runway change take...

Attributes
ACN	790284
Time
Date	200806
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : las.airport
State Reference	NV
Altitude	msl single value : 11500
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : l30.tracon
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Route In Use	arrival star : grnpa
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
ASRS Report	790284
Events
Anomaly	altitude deviation : crossing restriction not met non adherence : published procedure
Independent Detector	other flight crewa
Resolutory Action	none taken : detected after the fact
Supplementary
Problem Areas	Flight Crew Human Performance
Primary Problem	Flight Crew Human Performance

Narrative:

During descent into las on the grnpa arrival; we crossed luxor at 12000 ft. After passing luxor; we were given our arrival runway; which was different than what we had expected. I started to change the arrival information in the FMS; while the captain was flying. When I finished updating the FMS; I looked up to see our altitude was about 11500 ft instead of 11000 ft as we crossed grnpa intersection. Right at the same time; we were cleared direct to troop intersection and down to 7000 ft. There was no traffic conflict and no aircraft in our area. I'm not really sure why the event occurred. I was rapidly changing inputs in the FMS and unable to determine afterwards what had happened. The captain; who was the PF; thought that we were in selected speed and managed descent prior to crossing grnpa. I was making changes to the FMS and did not see what had happened. If crews maintain managed speed and managed descent; these types of problems would be less likely. The situation was compounded by the changes that ATC gave us at a busy time.

Original NASA ASRS Text

Title: FO RPTS MISSING CROSSING RESTR AT GRNPA ON THE ARR TO LAS AFTER RWY CHANGE TAKES HIM OUT OF THE LOOP FOR FMGC CHANGES.

Narrative: DURING DSCNT INTO LAS ON THE GRNPA ARR; WE CROSSED LUXOR AT 12000 FT. AFTER PASSING LUXOR; WE WERE GIVEN OUR ARR RWY; WHICH WAS DIFFERENT THAN WHAT WE HAD EXPECTED. I STARTED TO CHANGE THE ARR INFO IN THE FMS; WHILE THE CAPT WAS FLYING. WHEN I FINISHED UPDATING THE FMS; I LOOKED UP TO SEE OUR ALTITUDE WAS ABOUT 11500 FT INSTEAD OF 11000 FT AS WE CROSSED GRNPA INTXN. RIGHT AT THE SAME TIME; WE WERE CLEARED DIRECT TO TROOP INTXN AND DOWN TO 7000 FT. THERE WAS NO TFC CONFLICT AND NO ACFT IN OUR AREA. I'M NOT REALLY SURE WHY THE EVENT OCCURRED. I WAS RAPIDLY CHANGING INPUTS IN THE FMS AND UNABLE TO DETERMINE AFTERWARDS WHAT HAD HAPPENED. THE CAPT; WHO WAS THE PF; THOUGHT THAT WE WERE IN SELECTED SPEED AND MANAGED DSCNT PRIOR TO CROSSING GRNPA. I WAS MAKING CHANGES TO THE FMS AND DID NOT SEE WHAT HAD HAPPENED. IF CREWS MAINTAIN MANAGED SPEED AND MANAGED DSCNT; THESE TYPES OF PROBLEMS WOULD BE LESS LIKELY. THE SITUATION WAS COMPOUNDED BY THE CHANGES THAT ATC GAVE US AT A BUSY TIME.

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.

First officer reports missing crossing restr at grnpa on the arrival to las after runway change takes him out of the loop for FMGC changes.