Small Aircraft; Low Wing; 1 Eng; Fixed Gear
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Flight Instructor; Flight Crew Multiengine
Flight Crew Last 90 Days 150; Flight Crew Total 6200; Flight Crew Type 1
Human-Machine Interface; Situational Awareness
ATC Issue All Types; Aircraft Equipment Problem Less Severe; Deviation - Altitude Overshoot; Deviation / Discrepancy - Procedural Clearance; Deviation / Discrepancy - Procedural Published Material / Policy
Air Traffic Control Issued New Clearance; Air Traffic Control Provided Assistance; Flight Crew Requested ATC Assistance / Clarification; Flight Crew Returned To Clearance
Aircraft; Human Factors; Environment - Non Weather Related
We were doing approaches on an IFR flight plan because ATC currently won't allow practice approaches due to; we were told; coronavirus staffing levels.  Being on an actual IFR flight plan increased the complexity of what should have been simple currency training in visual conditions to get instrument currency.The aircraft; an Aircraft X type; was newly purchased and had been flown VFR by my student (I trained him and signed him off for an instrument rating; he passed on the first attempt almost a year ago); but he had yet to take it IFR.  It is nicely equipped with two Dynon combination PFD/MFD's and a Garmin GPS NAV/COM.  I have 1000-2000 hours on Garmin products; both GPS and G1000 systems; but only about a dozen hours on an Aircraft Y type with similar Dynon systems and no prior hours on an Aircraft X type.We took off from ZZZ1 and shot two approaches into ZZZ2 (about 15 NM away) and were being vectored for a last approach into ZZZ1 to a full stop.  I was simultaneously looking for traffic; explaining a point about GPS approach procedure; listening to another pilot on the radio report his position; and looking out for a scattered layer that was getting lower as the flight progressed and that we were just about to go into.  The autopilot was on and I noticed the aircraft climbing through 2;800 feet.  I thought I remembered that ZZZ approach had given us an altitude of 2;000 but I wasn't quite sure (my student was handling the radios); so I jumped on the radio and made an inquiry.  Approach confirmed we had been given an altitude of 2;000.  I immediately had my student hold the altitude we were at while I waited to jump in on the frequency as it was congested.  I reported that we were inadvertently at 2;800 and asked what altitude they wanted us at.  They replied 2;000.  I said we would descend to 2;000 which we did immediately.  ATC did not ask us to call a number when we got on the ground or make any other mention of it.The autopilot should have stopped the plane climbing at 2000.  Neither of us could determine why it didn't as it worked fine leveling off at altitudes both before and after.  I can only guess it was user input error on the part of my student.  When he changed it to descend to 2;000 and hold that altitude it worked just fine.I believe the reason why I didn't notice the altitude deviation sooner than reaching 800 feet over our assigned altitude was a combination of sensory overload of having to teach; look for traffic; listen to radio chatter; look out for entering clouds (which should have been less of a consideration since we were on an actual IFR plan); combined with a lack of experience on the Dynon systems which limited my rapid acquisition of altitude information.I shall endeavor in the future to practice with the Dynon systems more in VFR conditions before venturing into IFR.
Flight Instructor reported an altitude overshoot due to unfamiliarity with aircraft equipment.