Heading track position deviation induced by erring FMS.

Attributes
ACN	295975
Time
Date	199502
Day	Tue
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : dfw
State Reference	TX
Altitude	msl bound lower : 23000 msl bound upper : 23000
Environment
Flight Conditions	VMC
Light	Dawn
Aircraft 1
Controlling Facilities	artcc : zfw artcc : zfw
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other
Route In Use	enroute : direct enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 310 flight time total : 19000 flight time type : 3840
ASRS Report	295975
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : flight engineer pilot : atp pilot : cfi
Experience	flight time last 90 days : 100 flight time total : 7200 flight time type : 100
ASRS Report	295777
Events
Anomaly	aircraft equipment problem : less severe non adherence : clearance other anomaly other other spatial deviation
Independent Detector	other controllera
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	Pilot Deviation

Narrative:

FMS locked in a wind of 140 degrees, 110 KTS and kept taking aircraft south of course. Center questioned our navigation and gave us a 30 degree left turn and cleared us direct to the eic VOR. We were never told how far off course we were but we know that we were south of our departure radial. FMS was turned off and flight proceeded normally. False wind remained in FMS until landing. FMS worked normal next flight segment.

Original NASA ASRS Text

Title: HDG TRACK POS DEV INDUCED BY ERRING FMS.

Narrative: FMS LOCKED IN A WIND OF 140 DEGS, 110 KTS AND KEPT TAKING ACFT S OF COURSE. CTR QUESTIONED OUR NAV AND GAVE US A 30 DEG L TURN AND CLRED US DIRECT TO THE EIC VOR. WE WERE NEVER TOLD HOW FAR OFF COURSE WE WERE BUT WE KNOW THAT WE WERE S OF OUR DEP RADIAL. FMS WAS TURNED OFF AND FLT PROCEEDED NORMALLY. FALSE WIND REMAINED IN FMS UNTIL LNDG. FMS WORKED NORMAL NEXT FLT SEGMENT.

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.