Incident Overview
On a training flight involving touch-and-go landings, the student pilot reported a burning smell and a lack of engine power while on the downwind leg, approximately one mile west of the departure runway. The certified flight instructor (CFI) manipulated the throttle and observed that the manifold pressure needle followed throttle movements, then returned control to the student. When the student again reported no engine power, the CFI assumed control, turned east to land on a taxiway, and executed a hard landing short of the taxiway.
Fuel and Engine Examination
After the incident, sufficient fuel was confirmed to sustain engine operation, and the fuel supply was tested and found free of contaminants. The engine was started and operated only up to 1,500 RPM due to damage sustained to the propeller assembly. Subsequently, the engine was sent to the manufacturer's facility, where it was operated and the only discrepancy noted was a fuel flow that was 9 pounds per hour (PPH) leaner than specification at 80 PPH.
Cause Determination
Despite the examination, no determination could be made as to the reason for the loss of engine power.