Flight Crew Commercial; Flight Crew Flight Instructor; Flight Crew Multiengine; Flight Crew Instrument
Flight Crew Last 90 Days 146; Flight Crew Total 1489; Flight Crew Type 321
Distraction; Situational Awareness
Aircraft Equipment Problem Critical; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Fuel Issue
Flight Crew Overcame Equipment Problem
Human Factors
Training a student and while doing traffic pattern work the engine lost power due to the right tank running out of gas.  I told Tower that we had lost engine and then performed the restart procedure.  I was able to get power restored and reported to Tower that engine was running fine.Here is a recount of the chain of events.  I had flown with one of my other students in the evening (1 hour) and had ask the FBO to refuel plane the next morning due to the early closure due to COVID-19.  Upon returning the next morning to fly with another student that had about XX hours of instruction; I had student go out to plane and start the preflight. Student did the preflight and I came up when student was around on the left side of the plane and finished up the preflight with student.  I did not; however go back and check the right tank to make sure it was to the tabs.  We got in and started the engine and taxied out to the runway during the run up and engine check all the gauges seemed to indicate the normal amount settings including the fuel tanks.  We had flown about 1.2 hours when the incident happened and I immediately looked at the fuel tanks and noticed it was indicating empty.In assuming that the FBO had fueled the plane and that the student had performed a good preflight was my downfall; even though this had a good outcome it has opened my eyes to be vigilant in checking and making sure for myself that the preflight is done properly.  I will always do the preflight myself; even after my student has completed their check.
Instructor pilot reported not checking the fuel status before departure resulting in a temporary loss of power due to fuel starvation in one of the tanks.