After an ATC vector; the controller notified a BE20 pilot of his aircraft's heading error which was ...

Narrative:

[I was] climbing out in the morning through mixed VMC and IMC. [I was] assigned right turn to 260 degrees. I set heading bug and watched airplane turning the correct direction. I then proceeded to go through the climb checklist. I watched the airplane stop on the assigned heading and continued the climb checklist. I glanced at [the garmin] 696 and saw that the airplane was on an approximate 180 degree heading. I compared it to the pilot HSI and considered that perhaps the [garmin] 696 was not updating for some reason. ATC advised that they instructed me to make a right turn and I had actually made a left turn. I then compared pilot HSI to co-pilot HSI and wet compass. I realized that the HSI was off by approximately 80 degrees. I advised ATC that I had an autopilot issue. They switched me to center and I advised that I needed a heading check. The HSI slowly came back to a correct heading. No other problems in flight once I determined what the problem was. Landed and contacted contract avionics. We went through trouble shooting and noticed that pilot HSI would not slave. Co-pilot's would. At the end of the flight; the HSI was basically on the correct heading. The avionics technician advised that I should taxi around to see if it had aligned again. It seemed to be correct. They advised watch for more trouble and we would switch gyros when back in town. I operated off of #2 drive for the rest of the flight and put [it] in maintenance the next day. Avionics advised that they switched gyros and just watch to see if problem goes to co-pilot's instruments.

Original NASA ASRS Text

Title: After an ATC vector; the Controller notified a BE20 pilot of his aircraft's heading error which was found to be about 80 degrees. The heading source was switched to number 2 and the flight continued until maintenance was addressed later.

Narrative: [I was] climbing out in the morning through mixed VMC and IMC. [I was] assigned right turn to 260 degrees. I set heading bug and watched airplane turning the correct direction. I then proceeded to go through the climb checklist. I watched the airplane stop on the assigned heading and continued the climb checklist. I glanced at [the Garmin] 696 and saw that the airplane was on an approximate 180 degree heading. I compared it to the pilot HSI and considered that perhaps the [Garmin] 696 was not updating for some reason. ATC advised that they instructed me to make a right turn and I had actually made a left turn. I then compared pilot HSI to co-pilot HSI and wet compass. I realized that the HSI was off by approximately 80 degrees. I advised ATC that I had an autopilot issue. They switched me to Center and I advised that I needed a heading check. The HSI slowly came back to a correct heading. No other problems in flight once I determined what the problem was. Landed and contacted contract avionics. We went through trouble shooting and noticed that pilot HSI would not slave. Co-pilot's would. At the end of the flight; the HSI was basically on the correct heading. The Avionics Technician advised that I should taxi around to see if it had aligned again. It seemed to be correct. They advised watch for more trouble and we would switch gyros when back in town. I operated off of #2 drive for the rest of the flight and put [it] in maintenance the next day. Avionics advised that they switched gyros and just watch to see if problem goes to co-pilot's instruments.

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.

Attributes
ACN	930713
Time
Date	201101
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Flight Conditions	Mixed
Light	Daylight
Aircraft 1
Make Model Name	Super King Air 200
Operating Under FAR Part	Part 91
Flight Phase	Climb
Route In Use	Direct
Flight Plan	IFR
Component
Aircraft Component	AHRS/ND
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Air Transport Pilot (ATP) Flight Crew Flight Instructor Flight Crew Instrument Flight Crew Multiengine
Experience	Flight Crew Last 90 Days 40 Flight Crew Total 2500 Flight Crew Type 170
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Track / Heading All Types

After an ATC vector; the controller notified a BE20 pilot of his aircraft's heading error which was found to be about 80 degrees. The heading source was switched to number 2 and the flight continued until maintenance was addressed later.