Narrative:

After starting my takeoff roll; the controller changed my departure heading to 'left turn to 250 degrees'. I set the heading bug to 250 degrees and everything seemed appropriate. I continued the takeoff roll. I was cleared to 3;000 ft. At approximately 300 ft; I was told to turn left when altitude permitted. I started my turn to the left and climbed toward 3;000 ft visually watching for traffic and terrain. I changed my focus to the gages and when I reached my heading of 250 degrees; approach control told me to turn right to 310 degrees and I turned right to 310 degrees. Approach then told me to 'turn right 350 degrees immediate' and I banked 30 degrees turning to the right to 350 degrees. Approach asked if I was having compass problems and I said no because at that point everything seemed to be behaving normally. At that point; I cross checked my heading indicator with the copilots and the whiskey compass and found a 50 degree disparity between my indicator and the copilots. At this point I relied solely on the copilots heading indicator and whiskey compass during the remaining vectors. The remaining flight was uneventful. During the 'loss of separation' the copilot sitting in the right seat had identified the traffic visually to help maintain visual separation. Trouble shooting the pilot side HSI seemed to suggest the auto slaving mechanism was not working properly. Manually setting the HSI seemed to correct the problem allowing for the flight to be continued safely. The HSI has been removed from the plane and is currently being tested to determine the reason for the failure.

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Original NASA ASRS Text

Title: A C-414 suffered a loss of separation when the pilot failed to align his malfunctioning HSI compass prior to takeoff and thus flew headings assigned by ATC with an error of approximately 50 degrees.

Narrative: After starting my takeoff roll; the controller changed my departure heading to 'left turn to 250 degrees'. I set the heading bug to 250 degrees and everything seemed appropriate. I continued the takeoff roll. I was cleared to 3;000 FT. At approximately 300 FT; I was told to turn left when altitude permitted. I started my turn to the left and climbed toward 3;000 FT visually watching for traffic and terrain. I changed my focus to the gages and when I reached my heading of 250 degrees; Approach Control told me to turn right to 310 degrees and I turned right to 310 degrees. Approach then told me to 'turn right 350 degrees immediate' and I banked 30 degrees turning to the right to 350 degrees. Approach asked if I was having compass problems and I said no because at that point everything seemed to be behaving normally. At that point; I cross checked my heading indicator with the copilots and the whiskey compass and found a 50 degree disparity between my indicator and the copilots. At this point I relied solely on the copilots heading indicator and whiskey compass during the remaining vectors. The remaining flight was uneventful. During the 'loss of separation' the copilot sitting in the right seat had identified the traffic visually to help maintain visual separation. Trouble shooting the pilot side HSI seemed to suggest the auto slaving mechanism was not working properly. Manually setting the HSI seemed to correct the problem allowing for the flight to be continued safely. The HSI has been removed from the plane and is currently being tested to determine the reason for the failure.

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.