Narrative:

[Assigned} runway 13 lga; whitestone climb. While entering the runway; we received an EFIS comp mon caution message. We selected dg mode on the compass panel and manually aligned the heading indicator to runway heading; per our procedures. After successfully completing the departure procedure; we were instructed by ATC to fly directly to eliot intersection. While in a coordinated; stable; climbing turn; the pilot not flying reselected magnetic mode in accordance with the after take-off checklist. Both heading indicators then swung wildly; and settled on a heading about 50 degrees different then what dg mode had indicated. Our FMS set a course to eliot; and we began to turn toward it. At this time; our moving map displays blanked and presented a red magnetic flag. We rolled out on an approximate course to eliot and consulted the magnetic compass. It indicated that we were not flying in the right direction. Just as the pilot not flying was about to contact ATC to inform them of our issue; they called us and informed us we were not on a heading to eliot. We replied that we had lost our navigation system and they issued a vector; which I turned to using timed turns with the magnetic compass. After consulting the aom volume one; the pilot not flying again selected dg mode; realigned the heading indicators to the magnetic compass; and reselected magnetic mode. The heading indicators aligned properly; and the moving map reappeared. We queried ATC; and they confirmed that we were in fact on course to eliot. No further defects were noted; and we elected to continue. At no time did we violate surrounding airspace; or conflict with other traffic. The aom volume one indicates that the compass mode should only be changed when the aircraft is stable. In fact; the mode should only be changed in straight and level flight. This should be an aircraft limitation.

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Original NASA ASRS Text

Title: A CRJ 700 received an EFIS COMP MON while in position on LGA Runway 13 so; as per SOP; the crew switched to the DG Mode. After takeoff when the MAG Mode was selected the AHRS and ND displayed widely differing information and ATC issued vectors until the compass system was realigned in level flight.

Narrative: [Assigned} Runway 13 LGA; Whitestone Climb. While entering the runway; we received an EFIS COMP MON Caution message. We selected DG mode on the compass panel and manually aligned the heading indicator to runway heading; per our procedures. After successfully completing the departure procedure; we were instructed by ATC to fly directly to ELIOT Intersection. While in a coordinated; stable; climbing turn; the pilot not flying reselected MAG mode in accordance with the After Take-off Checklist. Both heading indicators then swung wildly; and settled on a heading about 50 degrees different then what DG mode had indicated. Our FMS set a course to ELIOT; and we began to turn toward it. At this time; our moving map displays blanked and presented a red MAG flag. We rolled out on an approximate course to ELIOT and consulted the magnetic compass. It indicated that we were not flying in the right direction. Just as the pilot not flying was about to contact ATC to inform them of our issue; they called us and informed us we were not on a heading to ELIOT. We replied that we had lost our navigation system and they issued a vector; which I turned to using timed turns with the magnetic compass. After consulting the AOM Volume one; the pilot not flying again selected DG mode; realigned the heading indicators to the magnetic compass; and reselected MAG mode. The heading indicators aligned properly; and the moving map reappeared. We queried ATC; and they confirmed that we were in fact on course to ELIOT. No further defects were noted; and we elected to continue. At no time did we violate surrounding airspace; or conflict with other traffic. The AOM Volume one indicates that the compass mode should only be changed when the aircraft is stable. In fact; the mode should only be changed in straight and level flight. This should be an aircraft limitation.

Data retrieved from NASA's ASRS site as of April 2012 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.