Background
The accident occurred during a training flight conducting a practice NDB-A approach. The certified flight instructor (CFI) was simulating an engine failure by idling the left engine during the approach. The student pilot was executing emergency procedures for a single-engine approach.
Accident Sequence
After completing the procedure turn and turning inbound, the CFI set the left engine to zero thrust. The airplane was configured with the landing gear up and flaps at 10 degrees for an intended circle-to-land approach to runway 03. Upon entering the traffic pattern, the student was too close to the runway on the downwind leg, overshot the runway, and was high when turning base to final. The student then reduced both engines to idle, extended the flaps to 25 degrees, lowered the landing gear, and completed the landing checklist.
The CFI called for a go-around. The student applied both throttles full forward, but the CFI noticed the airplane was not climbing. After confirming that both throttles were forward, the CFI retracted the landing gear and flaps. The student in the back seat warned to watch the airspeed. They pushed the nose forward to maintain airspeed above 66 knots. Despite these actions, the airplane continued to descend until it contacted the ground.
The airplane came to rest in the dirt area between the taxiway and runway 6/24. Runway 24 was the active runway. Winds were from 280 degrees at 12 knots, and the density altitude was calculated at 9,080 feet. Runway 03, selected by the CFI, was 3,930 feet long and 60 feet wide; it was not the active runway and lacked runway lighting.
Post-Accident Findings
Post-accident examination of the airplane revealed that the left propeller signatures were consistent with rotation at ground impact but not at a significant power level. The right propeller signatures were consistent with high power. After substituting another propeller, the left engine was placed on a test stand; it started within a few propeller blade revolutions, responded to throttle operation, and ran smoothly without hesitation.
The pilot operating handbook for the airplane states that flaps should be raised on both normal and single-engine go-arounds, but includes a cautionary note that a loss of altitude may occur until a climb is established. The manufacturer calculated that the airplane should have had a positive climb rate of 90 feet per minute with the gear and flaps retracted and the left engine at zero thrust.