A BE36 pilot was distressed that ATC scolded him for a purposeful track deviation for weather when; ...

Attributes
ACN	1184178
Time
Date	201406
Local Time Of Day	1201-1800
Place
Locale Reference	JAX.Airport
State Reference	FL
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Make Model Name	Bonanza 36
Operating Under FAR Part	Part 91
Flight Phase	Cruise
Route In Use	Direct
Flight Plan	IFR
Component
Aircraft Component	Autopilot
Person 1
Function	Pilot Flying Single Pilot
Qualification	Flight Crew Multiengine Flight Crew Instrument Flight Crew Flight Instructor Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 98 Flight Crew Total 7437 Flight Crew Type 253
Events
Anomaly	ATC Issue All Types Aircraft Equipment Problem Less Severe Deviation - Track / Heading All Types Inflight Event / Encounter Loss Of Aircraft Control

Narrative:

I was cruising at 8;000 MSL on a clearance direct to hevvn intersection. The autopilot was engaged in navigation mode and altitude hold and the heading bug was centered on my current heading. I was in VMC conditions. There were some build ups in the area; but none along my flight path at that moment. The autopilot made an uncommanded hard left bank (I believe the autopilot disengaged but I am not sure.) I took the controls; pressed the autopilot disengage button; and smoothly rolled wings level and then returned back on course. There were no unusual attitudes and minimal change in altitude. I believe the change in heading was close to 90 degrees by the time I rolled wings level and then into the right hand turn. Once back on course; I reengaged the autopilot and there were no further issues the remainder of the flight.as I was recovering the aircraft; I received a call from ATC scolding me for deviating 'for weather' and that I was on an IFR flight plan and had to ask before doing so. I would like to reiterate that this was not a weather deviation. I also explained to the controller that it was and autopilot malfunction not an intended deviation. I also had every intention of contacting ATC to let them know that a deviation had occurred; but I wanted to fly the aircraft first and then communicate.

Original NASA ASRS Text

Title: A BE36 pilot was distressed that ATC scolded him for a purposeful track deviation for weather when; in actuality; his autopilot had malfunctioned and turned the aircraft some 90 degrees left before he could disconnect it and return to his cleared track.

Narrative: I was cruising at 8;000 MSL on a clearance direct to HEVVN Intersection. The autopilot was engaged in NAV mode and ALT HOLD and the heading bug was centered on my current heading. I was in VMC conditions. There were some build ups in the area; but none along my flight path at that moment. The autopilot made an uncommanded hard left bank (I believe the autopilot disengaged but I am not sure.) I took the controls; pressed the autopilot disengage button; and smoothly rolled wings level and then returned back on course. There were no unusual attitudes and minimal change in altitude. I believe the change in heading was close to 90 degrees by the time I rolled wings level and then into the right hand turn. Once back on course; I reengaged the autopilot and there were no further issues the remainder of the flight.As I was recovering the aircraft; I received a call from ATC scolding me for deviating 'for weather' and that I was on an IFR flight plan and had to ask before doing so. I would like to reiterate that this was not a weather deviation. I also explained to the controller that it was and autopilot malfunction not an intended deviation. I also had every intention of contacting ATC to let them know that a deviation had occurred; but I wanted to FLY the aircraft first and then communicate.

Data retrieved from NASA's ASRS site 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.