Narrative:

This is a revision of a report that I sent in 2-3 days ago and involves information developed since that first report which changes the nature of the incident. I had reported that I was flying an airway via my flight planned route when the controller advised me that I was 11 mi off course. I initially reported that my HSI must have been coupled to my LORAN even though I had pushed the selector button that switches between the LORAN and the VOR. That button had stuck in the past and I thought that it must have stuck on 'LORAN'! Upon returning home (denver) I had my avionics shop check my HSI which I had them calibrate around 3 weeks before and assumed was functioning properly. Nevertheless, they found irregularities which explain the problem that I experienced. The HSI was around 4 degree off. The 'tail' of the obs needle was bent and did not indicate the correct right, the nose and the tail did not match. Although my original evaluation did not really explain the incident to my satisfaction, it is all that I could think of that could have caused the problem. The HSI problems, which were discovered only yesterday, makes a lot more sense. The action that I could have taken to prevent the incident also becomes very clear. I will always xchk with my #2 VOR. I may not have known which VOR was off but I would have been alerted to a problem and could have advised the controller. The next question is why I didn't become aware of the problem with this 'bent tail' before. The reason is that I rarely track outbnd from a VOR, usually use only the needle pointer with my RNAV equipment. I tracked outbnd in this instance because the airway from eau to ste is a dogleg. I saw that my selector button to couple either my LORAN or my VOR to the HSI was still on LORAN. From time to time, you have to hit that button 2 or 3 times to set it to switch. All I would have had to do was to double check the indicator and I would have caught the problem.

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Original NASA ASRS Text

Title: DEVIATION FROM AIRWAY ACCOUNT HSI REFERENCED TO LORAN VERSUS VOR.

Narrative: THIS IS A REVISION OF A RPT THAT I SENT IN 2-3 DAYS AGO AND INVOLVES INFO DEVELOPED SINCE THAT FIRST RPT WHICH CHANGES THE NATURE OF THE INCIDENT. I HAD RPTED THAT I WAS FLYING AN AIRWAY VIA MY FLT PLANNED ROUTE WHEN THE CTLR ADVISED ME THAT I WAS 11 MI OFF COURSE. I INITIALLY RPTED THAT MY HSI MUST HAVE BEEN COUPLED TO MY LORAN EVEN THOUGH I HAD PUSHED THE SELECTOR BUTTON THAT SWITCHES BTWN THE LORAN AND THE VOR. THAT BUTTON HAD STUCK IN THE PAST AND I THOUGHT THAT IT MUST HAVE STUCK ON 'LORAN'! UPON RETURNING HOME (DENVER) I HAD MY AVIONICS SHOP CHK MY HSI WHICH I HAD THEM CALIBRATE AROUND 3 WEEKS BEFORE AND ASSUMED WAS FUNCTIONING PROPERLY. NEVERTHELESS, THEY FOUND IRREGULARITIES WHICH EXPLAIN THE PROB THAT I EXPERIENCED. THE HSI WAS AROUND 4 DEG OFF. THE 'TAIL' OF THE OBS NEEDLE WAS BENT AND DID NOT INDICATE THE CORRECT R, THE NOSE AND THE TAIL DID NOT MATCH. ALTHOUGH MY ORIGINAL EVALUATION DID NOT REALLY EXPLAIN THE INCIDENT TO MY SATISFACTION, IT IS ALL THAT I COULD THINK OF THAT COULD HAVE CAUSED THE PROB. THE HSI PROBS, WHICH WERE DISCOVERED ONLY YESTERDAY, MAKES A LOT MORE SENSE. THE ACTION THAT I COULD HAVE TAKEN TO PREVENT THE INCIDENT ALSO BECOMES VERY CLR. I WILL ALWAYS XCHK WITH MY #2 VOR. I MAY NOT HAVE KNOWN WHICH VOR WAS OFF BUT I WOULD HAVE BEEN ALERTED TO A PROB AND COULD HAVE ADVISED THE CTLR. THE NEXT QUESTION IS WHY I DIDN'T BECOME AWARE OF THE PROB WITH THIS 'BENT TAIL' BEFORE. THE REASON IS THAT I RARELY TRACK OUTBND FROM A VOR, USUALLY USE ONLY THE NEEDLE POINTER WITH MY RNAV EQUIP. I TRACKED OUTBND IN THIS INSTANCE BECAUSE THE AIRWAY FROM EAU TO STE IS A DOGLEG. I SAW THAT MY SELECTOR BUTTON TO COUPLE EITHER MY LORAN OR MY VOR TO THE HSI WAS STILL ON LORAN. FROM TIME TO TIME, YOU HAVE TO HIT THAT BUTTON 2 OR 3 TIMES TO SET IT TO SWITCH. ALL I WOULD HAVE HAD TO DO WAS TO DOUBLE CHK THE INDICATOR AND I WOULD HAVE CAUGHT THE PROB.

Data retrieved from NASA's ASRS site as of August 2007 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.