Narrative:

On ground holding short of departure runway 22L received 'left pack autofail'. Advised tower that we would need to work a maintenance problem and could not takeoff. Crossed runway and held short other side and performed QRH procedure for 'left pack autofail'. Could not control pack and turned off. Consulted dispatcher and maintenance control and decision made to defer pack and run new numbers for lower altitude and single pack operations. After we finished with problem ready to takeoff received 'EFIS comp mon' caution message along with heading flag. Cross-checked heading on captain/first officer and standby (stby) heading and saw first officer heading was incorrect according to standby; captain heading matched standby. QRH says to find incorrect heading and slew to correct side. I slewed first officer heading to correct heading and all matched and showed normal. We were close to our min fuel so time was getting critical without having to return to gate and refuel. We completed all checklists and departed. We departed 22L with assigned heading of 220 up to 10;000 ft. First officer set heading 220 and we departed; showing all normal headings; after 400 ft AGL called for heading mode. Initiated turn and heading didn't seem right. At that time; dtw tower queried turn to 220. First officer readback heading and now I looked at standby heading and first officer heading and realized something was wrong. I stopped turn to left and realized our headings were wrong and standby showed us about a 205 heading. I began turn to right and flew stby heading indicator as primary instrument. We informed tower that we were now on 220 heading and had a malfunction. They turned us over to departure and we let them know that we had an instrument issue and need to level off and look into problem further. Departure was very cooperative and we leveled off at 6;000 ft and 250 KTS. We continued on 220 heading and I asked first officer to look at QRH for heading guidance so we could troubleshoot heading problem. We did not have any EICAS messages at this time. We looked at instruments and EFIS comp mon heading checklist. We figured out that both headings were 25 degrees off stby heading. We queried ATC what ground track heading they showed and it matched stby. Autopilot was on and slewed my heading to match stby. We asked ATC for a 90 degree heading change and rolled out and my heading was matched to stby. We next slewed first officer side to stby and match mine and asked for another turn. Both headings were now matched and agreed with stby and ATC ground track. We turned again 180 and monitored closely all three headings and cross-checked with ATC. All three headings matched and we discussed whether or not we should continue flight. We agreed that it was safe to continue flight and we did without further incident. Upon arriving I made an entry into maintenance logbook and talked to maintenance control. After describing issue and how resolved; maintenance controller informed me that it sounded like a stuck gimbal in gyro that might have cleared itself once we turned. Biggest threat that we encountered was time compression to get all new information regarding single pack updated and depart without dropping below min fuel. We completed all checklists and cross-checked everything and departed within fuel guidelines. When receiving 'EFIS comp mon' message we didn't feel that was too much of a threat because we corrected quickly and all showed normal at takeoff. Error on my part as pilot flying was initiating turn in wrong direction knowing it was not correct. I was slow to correct because information right after takeoff was incorrect on my pfd and there were not any associated EICAS messages to cue us that something was wrong. I feel my guard was let down a little bit because we departed within fuel limits and had completed all tasks associated with pack deferral. An error on my part was not increasing my situational awareness associated with 'EFIS comp mon' wereceived on the ground. I should have kept that in the back of my mind to be increasing my scan to make sure that heading issue wasn't a problem anymore.we followed a pace that kept us very busy because there is a lot involved in the deferral of a pack. Going through everything methodically and keeping everyone involved and updated is task saturating. Compiled with trying to depart with current fuel on board added to the stress. I felt my first officer and I completed all tasks in an efficient matter and the 'EFIS comp mon' threw us off. It occurred at the end of the pack deferral and we fixed it quickly. Personally I will increase my vigilance and cross-checking during high workload environments. An error on instrumentation without any EICAS messages is difficult to detect and continuously cross-checking on stby heading indicator will be more involved moving forward in my daily line flying.

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Original NASA ASRS Text

Title: A CRJ-700 crew preparing for takeoff on DTW Runway 22L first dealt with an AUTO PACK FAIL prior to takeoff; then an 'EFIS COMP MON' alert for a heading issue. After takeoff the crew determined both PFD 1 and 2 headings were off about 25 degrees but errors were cleared with QRH completion.

Narrative: On ground holding short of departure Runway 22L received 'L Pack AUTOFAIL'. Advised Tower that we would need to work a maintenance problem and could not takeoff. Crossed runway and held short other side and performed QRH procedure for 'L Pack AUTOFAIL'. Could not control pack and turned OFF. Consulted Dispatcher and Maintenance Control and decision made to defer pack and run new numbers for lower altitude and single pack operations. After we finished with problem ready to takeoff received 'EFIS COMP MON' caution message along with heading flag. Cross-checked heading on Captain/First Officer and Standby (STBY) heading and saw First Officer heading was incorrect according to Standby; Captain heading matched Standby. QRH says to find incorrect heading and slew to correct side. I slewed First Officer heading to correct heading and all matched and showed normal. We were close to our min fuel so time was getting critical without having to return to gate and refuel. We completed all checklists and departed. We departed 22L with assigned heading of 220 up to 10;000 FT. First officer set heading 220 and we departed; showing all normal headings; after 400 FT AGL called for heading mode. Initiated turn and heading didn't seem right. At that time; DTW Tower queried turn to 220. First Officer readback heading and now I looked at Standby heading and First Officer heading and realized something was wrong. I stopped turn to left and realized our headings were wrong and Standby showed us about a 205 heading. I began turn to right and flew STBY heading indicator as primary instrument. We informed Tower that we were now on 220 heading and had a malfunction. They turned us over to departure and we let them know that we had an instrument issue and need to level off and look into problem further. Departure was very cooperative and we leveled off at 6;000 FT and 250 KTS. We continued on 220 heading and I asked First Officer to look at QRH for heading guidance so we could troubleshoot heading problem. We did not have any EICAS messages at this time. We looked at instruments and EFIS COMP MON heading checklist. We figured out that both headings were 25 degrees off STBY heading. We queried ATC what ground track heading they showed and it matched STBY. Autopilot was on and slewed my heading to match STBY. We asked ATC for a 90 degree heading change and rolled out and my heading was matched to STBY. We next slewed First Officer side to STBY and match mine and asked for another turn. Both headings were now matched and agreed with STBY and ATC ground track. We turned again 180 and monitored closely all three headings and cross-checked with ATC. All three headings matched and we discussed whether or not we should continue flight. We agreed that it was safe to continue flight and we did without further incident. Upon arriving I made an entry into Maintenance logbook and talked to Maintenance Control. After describing issue and how resolved; Maintenance Controller informed me that it sounded like a stuck gimbal in gyro that might have cleared itself once we turned. Biggest threat that we encountered was time compression to get all new information regarding single pack updated and depart without dropping below min fuel. We completed all checklists and cross-checked everything and departed within fuel guidelines. When receiving 'EFIS COMP MON' message we didn't feel that was too much of a threat because we corrected quickly and all showed normal at takeoff. Error on my part as pilot flying was initiating turn in wrong direction knowing it was not correct. I was slow to correct because information right after takeoff was incorrect on my PFD and there were not any associated EICAS messages to cue us that something was wrong. I feel my guard was let down a little bit because we departed within fuel limits and had completed all tasks associated with pack deferral. An error on my part was not increasing my situational awareness associated with 'EFIS COMP MON' wereceived on the ground. I should have kept that in the back of my mind to be increasing my scan to make sure that heading issue wasn't a problem anymore.We followed a pace that kept us very busy because there is a lot involved in the deferral of a pack. Going through everything methodically and keeping everyone involved and updated is task saturating. Compiled with trying to depart with current fuel on board added to the stress. I felt my First Officer and I completed all tasks in an efficient matter and the 'EFIS COMP MON' threw us off. It occurred at the end of the pack deferral and we fixed it quickly. Personally I will increase my vigilance and cross-checking during high workload environments. An error on instrumentation without any EICAS messages is difficult to detect and continuously cross-checking on STBY heading indicator will be more involved moving forward in my daily line flying.

Data retrieved from NASA's ASRS site as of July 2013 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.