Large transport descending on approach has map shift. Heading deviation.

Attributes
ACN	316076
Time
Date	199509
Day	Wed
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : jfk
State Reference	NY
Altitude	msl bound lower : 3000 msl bound upper : 3000
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : n90 tower : jfk
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	descent : approach descent other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : cfi pilot : instrument pilot : flight engineer
Experience	flight time last 90 days : 250 flight time total : 12000 flight time type : 1500
ASRS Report	316076
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : less severe other spatial deviation
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : became reoriented
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

On VOR runway 13L (canarsie) approach. Crossed cri on FMC map, descending to 1013 ft and still showing over 1 mi to intersection, noticed that map course was moving us left of the freeway. Also, lead in lights were already turning to right. Airport barely visible to right through haze. We were left of course and close in and high. Threw out all the drag and made it ok. Wrote up map shift. Maintenance checked aircraft ok, said that was happening a lot, and problem was with group equipment. The next time we used raw data as primary navigation.

Original NASA ASRS Text

Title: LGT DSNDING ON APCH HAS MAP SHIFT. HDG DEV.

Narrative: ON VOR RWY 13L (CANARSIE) APCH. CROSSED CRI ON FMC MAP, DSNDING TO 1013 FT AND STILL SHOWING OVER 1 MI TO INTXN, NOTICED THAT MAP COURSE WAS MOVING US L OF THE FREEWAY. ALSO, LEAD IN LIGHTS WERE ALREADY TURNING TO R. ARPT BARELY VISIBLE TO R THROUGH HAZE. WE WERE L OF COURSE AND CLOSE IN AND HIGH. THREW OUT ALL THE DRAG AND MADE IT OK. WROTE UP MAP SHIFT. MAINT CHKED ACFT OK, SAID THAT WAS HAPPENING A LOT, AND PROB WAS WITH GROUP EQUIP. THE NEXT TIME WE USED RAW DATA AS PRIMARY NAV.

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.