Air carrier has compass precessing and creates gross navigation error.

Attributes
ACN	283772
Time
Date	199409
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	airport : msp
State Reference	MN
Aircraft 1
Controlling Facilities	tracon : msp
Operator	common carrier : air carrier
Make Model Name	MD-80 Super 80
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	climbout : intermediate altitude cruise other
Route In Use	enroute : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
ASRS Report	283772
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : flight engineer pilot : atp
Events
Anomaly	aircraft equipment problem : critical other spatial deviation
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : declared emergency other
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

Shortly after takeoff -- msp -- the #2 compass began precessing and giving gross navigation errors. In order to determine which compass was the problem and due to the navigation difficulties, declared and emergency and proceeded to ord. Ord was VFR.

Original NASA ASRS Text

Title: ACR HAS COMPASS PRECESSING AND CREATES GROSS NAV ERROR.

Narrative: SHORTLY AFTER TKOF -- MSP -- THE #2 COMPASS BEGAN PRECESSING AND GIVING GROSS NAV ERRORS. IN ORDER TO DETERMINE WHICH COMPASS WAS THE PROB AND DUE TO THE NAV DIFFICULTIES, DECLARED AND EMER AND PROCEEDED TO ORD. ORD WAS VFR.

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.