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

Attributes
ACN	571991
Time
Date	200301
Day	Mon
Local Time Of Day	1801 To 2400
Place
Locale Reference	airport : las.airport
State Reference	NV
Altitude	msl bound lower : 11000 msl bound upper : 13000
Environment
Flight Conditions	VMC
Light	Night
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	other
Flight Phase	descent : intermediate altitude
Route In Use	arrival star : skebr
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 200 flight time total : 15000 flight time type : 10000
ASRS Report	571991
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 290 flight time total : 5000 flight time type : 1200
ASRS Report	571992
Events
Anomaly	non adherence : clearance non adherence : company policies non adherence : far non adherence : published procedure other spatial deviation
Independent Detector	atc equipment other atc equipment : radar other controllera
Resolutory Action	controller : issued alert controller : issued new clearance flight crew : returned to intended or assigned course flight crew : overrode automation
Consequence	faa : reviewed incident with flight crew other
Supplementary
Problem Areas	Flight Crew Human Performance FAA Company Aircraft
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

During descent into las on the skebr RNAV 2 arrival, I changed the altitude in the CDU at misen to FL240 (vice the FL240A, which is never issued) and verified the rteing as far as skebr. I was behind the power curve getting the ATIS, so went off, recorded it, and computed the landing data. Distred now, I failed to return to the CDU and verify the rteing and approach the first officer had selected after skebr. After skebr, the aircraft turned direct shand on the ILS runway 25L. The controller quickly noticed we missed the turn to kepec and issued a heading of 320 degrees. We checked the CDU and saw that all the fixes after skebr on the arrival had been somehow deleted. We re-entered the arrival in the CDU and resumed the arrival direct ipumy. Fortunately, there was no traffic conflict or any problem caused by the deviation. The first officer, who had programmed the arrival, was unable to explain how the fixes were deleted. He recalled setting up the arrival, but said he did not line-select any fixes that would have caused the deletion of the RNAV fixes. I talked to a controller at las TRACON after the flight, and he told me he had seen aircraft proceed erroneously skebr-shand previously. He assured me there was no conflict and that no paperwork would be filed. Lesson learned -- I always verify the arrival rteing and approach, usually prior to descent. From now on, I will not allow any disruptions during this task.

Original NASA ASRS Text

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

Narrative: DURING DSCNT INTO LAS ON THE SKEBR RNAV 2 ARR, I CHANGED THE ALT IN THE CDU AT MISEN TO FL240 (VICE THE FL240A, WHICH IS NEVER ISSUED) AND VERIFIED THE RTEING AS FAR AS SKEBR. I WAS BEHIND THE PWR CURVE GETTING THE ATIS, SO WENT OFF, RECORDED IT, AND COMPUTED THE LNDG DATA. DISTRED NOW, I FAILED TO RETURN TO THE CDU AND VERIFY THE RTEING AND APCH THE FO HAD SELECTED AFTER SKEBR. AFTER SKEBR, THE ACFT TURNED DIRECT SHAND ON THE ILS RWY 25L. THE CTLR QUICKLY NOTICED WE MISSED THE TURN TO KEPEC AND ISSUED A HDG OF 320 DEGS. WE CHKED THE CDU AND SAW THAT ALL THE FIXES AFTER SKEBR ON THE ARR HAD BEEN SOMEHOW DELETED. WE RE-ENTERED THE ARR IN THE CDU AND RESUMED THE ARR DIRECT IPUMY. FORTUNATELY, THERE WAS NO TFC CONFLICT OR ANY PROB CAUSED BY THE DEV. THE FO, WHO HAD PROGRAMMED THE ARR, WAS UNABLE TO EXPLAIN HOW THE FIXES WERE DELETED. HE RECALLED SETTING UP THE ARR, BUT SAID HE DID NOT LINE-SELECT ANY FIXES THAT WOULD HAVE CAUSED THE DELETION OF THE RNAV FIXES. I TALKED TO A CTLR AT LAS TRACON AFTER THE FLT, AND HE TOLD ME HE HAD SEEN ACFT PROCEED ERRONEOUSLY SKEBR-SHAND PREVIOUSLY. HE ASSURED ME THERE WAS NO CONFLICT AND THAT NO PAPERWORK WOULD BE FILED. LESSON LEARNED -- I ALWAYS VERIFY THE ARR RTEING AND APCH, USUALLY PRIOR TO DSCNT. FROM NOW ON, I WILL NOT ALLOW ANY DISRUPTIONS DURING THIS TASK.

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.