Small Aircraft; Low Wing; 1 Eng; Fixed Gear
Flight Crew Instrument; Flight Crew Multiengine; Flight Crew Commercial
Flight Crew Last 90 Days 16; Flight Crew Total 1512; Flight Crew Type 300
Confusion; Situational Awareness; Training / Qualification; Communication Breakdown
ATC Issue All Types; Deviation - Track / Heading All Types; Deviation / Discrepancy - Procedural Clearance
Flight Crew Requested ATC Assistance / Clarification
Airspace Structure; Human Factors; Environment - Non Weather Related
I was flying the following route under IFR: ZZZ [route] ZZZ1. I requested RNAV XX and after ZZZ2 was instructed to fly heading 070 and later 'Direct ZZZZZ' (intermediate fix). Another aircraft with similar callsign responded to the instruction 'fly a 360' mistaking the instruction for them. The Approach Controller; who was extremely busy; repeated the instruction to me and due to the urgency in Controller's voice I also mistook the command also as a '360' (assuming imminent traffic conflict). Once the miscommunication issue was resolved I changed the autopilot mode from Heading to GPSS mode on the PFD. The approach was loaded but not activated and started to sequence to the next waypoint; ZZZ3. While I was troubleshooting I disabled the autopilot to roll the wings level and while selecting ZZZZZ Direct due to task saturation an altitude deviation occurred and the Approach Controller terminated the approach. Once composed I was instructed Direct ZZZZZ once more and cleared for the approach which was executed without further issue.Contributing Factors: This was the first instrument approach conducted using new avionic equipment; which was installed a few days prior to this flight. I had familiarized myself with the unit on the ground and with the vendor's simulator app and pilot manual; but not in combination with the PFD and autopilot. I was not sufficiently familiar with the new unit. Flying practice approaches with an instructor would have been appropriate. While I have received recent instruction with an instructor (prior to equipment upgrade however) this activity is contrary to the CDC social distancing requirements and I have been limiting my training while the pandemic is ongoing as a consequence. In consideration to the above it would have been appropriate to conduct several practice approaches VFR on a less busy day to properly familiarize myself with the unit. The deviation would likely have been avoided had I configured the unit to fly direct ZZZZZ prior to changing autopilot mode from Heading to GPSS. Disabling the autopilot exacerbated task saturation. The Approach Controller was a little difficult to understand due to the intensity of communication and workload. ZZZZZ is phonetically similar to 'Three Sixty'. The ZZZZZ waypoint is located in City X north east practice area. Student pilots and non-instrument rated pilots using flight following mistaking the instruction and mistakenly responding to a call made to another aircraft may negatively impact Approach Controller workload.
Pilot reported a track heading deviation when executing a 360 turn resulting from confusing a fix name which sounds like the number 360.