Incident Overview
During a training flight on the downwind leg, the instructor simulated a failure of the left engine by reducing manifold pressure to 11 inches Hg. She noted that they did not clear the engine during the visual approach and that the engine had been running rich.
Go-Around and Loss of Control
On short final approach, the instructor took control of the aircraft and applied full power to both engines for a go-around. The left engine did not accelerate, and the aircraft rolled rapidly to the left. In response, the instructor reduced engine power, and the aircraft rolled to a level attitude. It then touched down in a side slip on the runway, collapsing the landing gear.
Postcrash Examination
Postcrash examination of the left engine revealed that the spark plugs were fouled with combustion deposits. Additionally, the fuel control was operating at a rich mixture in the idle range due to sand contamination.