Date: 202101
Local time of day: 0601-1200
Location: ZZZ.TRACON, US
Flight conditions: IMC
Weather elements / visibility: Rain; 8
Light: Daylight
Aircraft: Small Aircraft; Low Wing; 1 Eng; Retractable Gear
Operator: Personal
Operating under: Part 91
Flight plan: IFR
Mission: Training
Flight phase: Climb
Airspace: Class E ZZZ2
ATC / advisory: TRACON ZZZ
Reporter organization: Personal
Reporter function: Instructor; Pilot Not Flying
Reporter qualification: Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Commercial; Flight Crew Flight Instructor
Human factors: Situational Awareness; Confusion; Distraction
Anomaly: Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Detector: Person Flight Crew
When detected: In-flight
Result: Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance; Flight Crew Returned To Clearance
Contributing factors: Environment - Non Weather Related; Human Factors
Primary problem: Environment - Non Weather Related

Narrative: I was providing instruction on new avionics for a client in Aircraft X. An IFR flight plan was filed by my client on his certificate. I briefed prior to engine start that he was PIC and that I was there to provide insight on the use of his new GTN 750. He had flown previously with this equipment; based on what he had told me. This was our first flight together in his aircraft.Prior to taxi; I reviewed with him how to load and activate approaches in his new GTN 750. He seemed familiar with its use and only asked a couple questions prior to departure. His knowledge of the features was adequate when I queried him on the unit.After takeoff from ZZZ Runway XXR; we were given a left turn to a heading of 070 and a climb to 3;000 feet. He engaged the autopilot at about 1;000 feet AGL. My client requested from ZZZ Approach the RNAV Y XXR but asked for a non-standard transition. He stated that he wanted the RNAV Y XXR to ZZZ 'via the ZZZZZ transition.' This is not a published transition and not what we briefed prior to departure. We had briefed previously that he would ask for vectors for the approach and he would repeat that same approach three times to increase familiarity with the equipment and its use in the approach environment. A short time later; we were given the instruction to climb to 3;000 feet and after that; to 'turn left direct ZZZZZ.' The autopilot began turning the aircraft to the right; presumably because he had switched from HDG mode to NAV mode without my knowledge. ATC queried and he once again read back the left turn. By the time I caught the erroneous turn direction and autopilot setting; the aircraft was well into the right turn. ATC then requested that we continue the right turn 'since we were already turning right and I have to keep you away from other traffic.'My client did as instructed and I queried ATC to confirm that we would overfly the ZZZZZ waypoint; then proceed outbound for the full approach. I apologized for the error on that same radio call. ATC responded in the affirmative; then cleared us for the approach. No further communication about the incorrect turn direction was made and the rest of the flight proceeded without incident.My client and I debriefed this issue and shared the lessons we learned. We both looked at this with an eye toward learning and future improvement.First; I reminded him of the importance of flying what we brief and that we will commit to always do so in the future. Second; as his flight instructor; it was my responsibility to catch the turn error and take control -- an effort I began but could not finish before ATC requested that he continue the right turn. Third; reliance on the autopilot worked against us and I suspect he switched from HDG to NAV mode without my noticing; initiating the right turn direct to ZZZZZ. Finally; business has been slow due to COVID and I have not been instructing as much as I normally would. I feel this last point is perhaps the most important one. As the pandemic has continued for nearly a year now; its effect on skills as pilots and flight instructors is being felt industry-wide.




Synopsis: Instructor pilot reported a track heading deviation during a training flight with a student.