MD80 crw had track deviation in ZAB class a airspace.

Attributes
ACN	497850
Time
Date	200101
Day	Fri
Local Time Of Day	1801 To 2400
Place
Locale Reference	navaid : abq.vortac
State Reference	NM
Altitude	msl single value : 31000
Environment
Light	Night
Aircraft 1
Controlling Facilities	artcc : zab.artcc
Operator	common carrier : air carrier
Make Model Name	MD-80 Super 80
Operating Under FAR Part	Part 121
Navigation In Use	other other
Flight Phase	cruise : level
Route In Use	enroute : direct
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	497850
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : multi engine pilot : instrument pilot : commercial
ASRS Report	497851
Events
Anomaly	aircraft equipment problem : less severe non adherence : clearance other anomaly other other spatial deviation
Independent Detector	atc equipment other atc equipment : radar other controllera other flight crewa other flight crewb
Resolutory Action	controller : issued new clearance controller : issued alert
Consequence	other other
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

Heading deviation. Over abq, with autoplt and gfms on, the gfms failed to track outbound on the airway to zun. The aircraft began a slight left turn, which I did not notice immediately, instead of tracking outbound. Zun appeared as the active waypoint, but without a bearing or distance. By the time I realized the aircraft had turned, we had drifted south of the airway. The FMA remained in navigation track the entire time. I turned back to the airway as ATC called to verify our clearance. We returned to the airway and then to zun. The first officer was on raw data, which I should have looked at immediately, instead of first trying to correct the gfms. I have never seen the gfms in navigation track and yet flying randomly. It worked the rest of the flight. This was a good lesson for me to pay much closer attention to the raw data.

Original NASA ASRS Text

Title: MD80 CRW HAD TRACK DEV IN ZAB CLASS A AIRSPACE.

Narrative: HDG DEV. OVER ABQ, WITH AUTOPLT AND GFMS ON, THE GFMS FAILED TO TRACK OUTBOUND ON THE AIRWAY TO ZUN. THE ACFT BEGAN A SLIGHT L TURN, WHICH I DID NOT NOTICE IMMEDIATELY, INSTEAD OF TRACKING OUTBOUND. ZUN APPEARED AS THE ACTIVE WAYPOINT, BUT WITHOUT A BEARING OR DISTANCE. BY THE TIME I REALIZED THE ACFT HAD TURNED, WE HAD DRIFTED S OF THE AIRWAY. THE FMA REMAINED IN NAV TRACK THE ENTIRE TIME. I TURNED BACK TO THE AIRWAY AS ATC CALLED TO VERIFY OUR CLRNC. WE RETURNED TO THE AIRWAY AND THEN TO ZUN. THE FO WAS ON RAW DATA, WHICH I SHOULD HAVE LOOKED AT IMMEDIATELY, INSTEAD OF FIRST TRYING TO CORRECT THE GFMS. I HAVE NEVER SEEN THE GFMS IN NAV TRACK AND YET FLYING RANDOMLY. IT WORKED THE REST OF THE FLT. THIS WAS A GOOD LESSON FOR ME TO PAY MUCH CLOSER ATTN TO THE RAW DATA.

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.