What happened
Prior to departure, the commercial pilot performed a check of the right wing fuel tanks and confirmed they contained fuel. The Certified Flight Instructor (CFI) inspected the left tanks, noting that the tip tank was full while the main tank level had decreased by approximately 1 1/2 inches.
Following a 30-minute local flight that included one touch-and-go maneuver and one go-around, the commercial pilot initiated a switch from the left main tank to the right main tank while on the downwind leg of the approach. During this process, the CFI observed a zero fuel indication. As the CFI was attempting to switch to another tank, the engine lost power.
The CFI transitioned back to the left main tank, which restored engine power; however, the aircraft contacted the terrain short of the runway.
The investigation
A post-accident inspection of the aircraft revealed that the right main fuel tank was empty.