Accident Description
A flight instructor and a student pilot were practicing an aborted takeoff following a simulated loss of power in the right engine. The student received a briefing on the procedure and was informed that the right engine would be used for the simulation. During the takeoff roll at 50 mph, the instructor simulated the power loss by reducing the mixture for that engine. The instructor reported that the student appeared to initiate the correct aborted takeoff sequence by retarding both throttles to idle.
After completing the simulated power loss and aborted takeoff, the instructor re-advanced the right engine mixture control. The right engine then surged with power, and the airplane veered off the left side of the runway into soft grass. The nose gear subsequently collapsed.
Aftermath
Following the accident, the instructor discovered that the student had not retarded the right throttle during the aborted takeoff. The instructor had believed the student fully retarded both throttles, but the right throttle remained advanced.