Narrative:

Departed on an IFR clearance climbing through 1;000 feet MSL with a right turn-out per IFR assigned clearance. Completing the right turn; the autopilot was engaged with navigation; altitude (3;000-feet) and vs set to 300 ft/min. The autopilot took command but pitched-up rapidly which quickly brought the airspeed from 83-knots to 65-knots. To avoid stalling the airplane; the autopilot was disengaged. The pitch-up configuring remained in place requiring a hard forward push on the yoke. Thinking the autopilot failed to disengaged; the circuit breaker was pulled. The airplane remained at a pitch-up attitude. The constant forward pressure on the yoke caused me to induce banking of the airplane in both left and right directions. It was for this reason that I felt the risk of losing complete control of the airplane and losing spatial orientation. Thinking there was something wrong with the autopilot; I [advised] ATC. ATC asked what I needed. I asked for vectors to VFR conditions. I was asked by ATC if I could climb and turn; I said yes. I allowed the airplane to climb slowly fearing that relaxing the yoke would allow the airplane to pitch up and stall. I had my student in the left seat verify that the autopilot was off. After a few minutes of trying to diagnose the problem; I realized that the autopilot trimmed up the airplane and all I had to do was re-trim the nose down. The autopilot was in fact off and never engaged after first disengagement command was sent. The cessna 172 has a G1000 avionics suite. Once the error was corrected I informed ATC that I had regained controlled of the aircraft and requested vectors to the ILS. We did managed to breakout into VFR at 3;000 feet. In retrospect; I should have recognized that cause of the pitch-up and made the correction sooner. But failing to do so; I allowed the problem to persist too long. I do appreciate ATC's professionalism and working with me. They were very busy that day but they gave me their full attention and for that I thank them.

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Original NASA ASRS Text

Title: C172 Flight Instructor experiences a pitch up and airspeed loss when the autopilot is engaged at 1;000 feet during climb. The autopilot is switched off but does not seem to disengage; making manual control difficult in IMC. ATC is advised and eventually it is determined that autopilot induced nose up trim is causing the problem and that the autopilot is indeed off.

Narrative: Departed on an IFR clearance climbing through 1;000 feet MSL with a right turn-out per IFR assigned clearance. Completing the right turn; the autopilot was engaged with NAV; ALT (3;000-feet) and VS set to 300 ft/min. The autopilot took command but pitched-up rapidly which quickly brought the airspeed from 83-knots to 65-knots. To avoid stalling the airplane; the autopilot was disengaged. The pitch-up configuring remained in place requiring a hard forward push on the yoke. Thinking the autopilot failed to disengaged; the circuit breaker was pulled. The airplane remained at a pitch-up attitude. The constant forward pressure on the yoke caused me to induce banking of the airplane in both left and right directions. It was for this reason that I felt the risk of losing complete control of the airplane and losing spatial orientation. Thinking there was something wrong with the autopilot; I [advised] ATC. ATC asked what I needed. I asked for vectors to VFR conditions. I was asked by ATC if I could climb and turn; I said yes. I allowed the airplane to climb slowly fearing that relaxing the yoke would allow the airplane to pitch up and stall. I had my student in the left seat verify that the autopilot was off. After a few minutes of trying to diagnose the problem; I realized that the autopilot trimmed up the airplane and all I had to do was re-trim the nose down. The autopilot was in fact off and never engaged after first disengagement command was sent. The Cessna 172 has a G1000 avionics suite. Once the error was corrected I informed ATC that I had regained controlled of the aircraft and requested vectors to the ILS. We did managed to breakout into VFR at 3;000 feet. In retrospect; I should have recognized that cause of the pitch-up and made the correction sooner. But failing to do so; I allowed the problem to persist too long. I do appreciate ATC's professionalism and working with me. They were very busy that day but they gave me their full attention and for that I thank them.

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.