B737-300 crew had track deviation while flying the skebr 2 RNAV approach into las.

Attributes
ACN	571948
Time
Date	200301
Day	Sun
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : l30.tracon
State Reference	NV
Altitude	msl single value : 13000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : l30.tracon
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Navigation In Use	ils localizer & glide slope : 25l other
Flight Phase	descent : approach
Route In Use	approach : instrument precision arrival star : skebr
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 10000 flight time type : 6000
ASRS Report	571948
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : less severe non adherence : clearance non adherence : far non adherence : published procedure non adherence : company policies other spatial deviation
Independent Detector	aircraft equipment other aircraft equipment : legs page of fmc other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance other
Consequence	other
Supplementary
Problem Areas	FAA Flight Crew Human Performance Aircraft Company
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were flying the skebr RNAV 2 arrival into las. As we crossed the clarr intersection, the LNAV legs page went from clarr to shand intersection on the runway 25L ILS. Seeing that we were now going to shand instead of skebr, the first officer, who was PF, went to re-enter skebr, as I told ATC what had happened, and we were given vectors for the approach. On the ground in lax, and once again inbound to daggett, we both looked to see that the skebr 2 arrival was programmed. Everything had been normal from dag to misen to clarr, I don't know while going from the legs page to the descent page and back, if we inadvertently deleted part of the arrival or what happened. We did notify ATC as soon as we started to go toward shand intersection.

Original NASA ASRS Text

Title: B737-300 CREW HAD TRACK DEV WHILE FLYING THE SKEBR 2 RNAV APCH INTO LAS.

Narrative: WE WERE FLYING THE SKEBR RNAV 2 ARR INTO LAS. AS WE CROSSED THE CLARR INTXN, THE LNAV LEGS PAGE WENT FROM CLARR TO SHAND INTXN ON THE RWY 25L ILS. SEEING THAT WE WERE NOW GOING TO SHAND INSTEAD OF SKEBR, THE FO, WHO WAS PF, WENT TO RE-ENTER SKEBR, AS I TOLD ATC WHAT HAD HAPPENED, AND WE WERE GIVEN VECTORS FOR THE APCH. ON THE GND IN LAX, AND ONCE AGAIN INBOUND TO DAGGETT, WE BOTH LOOKED TO SEE THAT THE SKEBR 2 ARR WAS PROGRAMMED. EVERYTHING HAD BEEN NORMAL FROM DAG TO MISEN TO CLARR, I DON'T KNOW WHILE GOING FROM THE LEGS PAGE TO THE DSCNT PAGE AND BACK, IF WE INADVERTENTLY DELETED PART OF THE ARR OR WHAT HAPPENED. WE DID NOTIFY ATC AS SOON AS WE STARTED TO GO TOWARD SHAND INTXN.

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.