Narrative:

On takeoff and run up all instruments appeared to be functioning normally. Above 1000 ft I attempted to turn on the autopilot. It would not engage in the heading mode. The flight director did not come up and the autopilot would not engage. This was my first sign that something was wrong. This probably occurred because it was not receiving heading information. I was given a turn to a heading; and the instruments did not cross check; but I did not receive any failure flags. I crosschecked the attitude indicator; with the turn coordinator; and they matched. It was at this point that I pinpointed the problem to the heading indicator. While I was doing this I asked ATC for a turn back towards the shore where I knew VMC was. During this initial troubleshoot period I believe I turned to a heading other than that assigned by ATC. Once I was sure that the airplane was stable I used the co-pilots heading indicator and crosschecked it with magnetic compass. The controller gave me no-gyro instructions to get to where I knew VMC was and I complied. I also declared an emergency while troubleshooting. I found VMC conditions and circled there. The weather at my departure airport was still IFR; but it looked like I could get in while maintaining VMC the entire way. The controller asked if I would like to try the approach if I could maintain visual the entire way. I said yes. I tried to do it visually but when I got closer to the airport I realized that maintaining VMC all the way in would not be possible. I asked to go back to the VMC area that I had just left; and that was approved. Eventually I got the field in sight; and asked for a contact approach because visibility was less than 3 miles. The contact approach and landing were uneventful. However; upon the power reduction the heading flag appeared on the HSI. The plane was written up; I coordinated with maintenance and the passengers seemed very pleased. They even mentioned that they appreciated my judgment.

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Original NASA ASRS Text

Title: A C402 pilot lost his heading indicator after takeoff in IMC; declared an emergency; and returned to land at departure airport.

Narrative: On takeoff and run up all instruments appeared to be functioning normally. Above 1000 FT I attempted to turn on the autopilot. It would not engage in the heading mode. The flight director did not come up and the autopilot would not engage. This was my first sign that something was wrong. This probably occurred because it was not receiving heading information. I was given a turn to a heading; and the instruments did not cross check; but I did not receive any failure flags. I crosschecked the attitude indicator; with the turn coordinator; and they matched. It was at this point that I pinpointed the problem to the heading indicator. While I was doing this I asked ATC for a turn back towards the shore where I knew VMC was. During this initial troubleshoot period I believe I turned to a heading other than that assigned by ATC. Once I was sure that the airplane was stable I used the co-pilots heading indicator and crosschecked it with magnetic compass. The controller gave me no-gyro instructions to get to where I knew VMC was and I complied. I also declared an emergency while troubleshooting. I found VMC conditions and circled there. The weather at my departure airport was still IFR; but it looked like I could get in while maintaining VMC the entire way. The controller asked if I would like to try the approach if I could maintain visual the entire way. I said yes. I tried to do it visually but when I got closer to the airport I realized that maintaining VMC all the way in would not be possible. I asked to go back to the VMC area that I had just left; and that was approved. Eventually I got the field in sight; and asked for a contact approach because visibility was less than 3 miles. The contact approach and landing were uneventful. However; upon the power reduction the heading flag appeared on the HSI. The plane was written up; I coordinated with Maintenance and the passengers seemed very pleased. They even mentioned that they appreciated my judgment.

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.