Incident Summary
Shortly after takeoff, the pilot reported that the engine lost substantial power. Subsequently, smoke appeared in the cockpit. The pilot reversed course with the intent to land at the departure airport.
Sequence of Events
When the pilot felt confident that he had the landing field made, he attempted to lower the landing gear. The red gear unsafe light illuminated, prompting the pilot to use the emergency crank-down procedures. He was unable to achieve full gear extension before the aircraft struck terrain short of the intended landing field.
Postflight Findings
A postflight inspection revealed a broken exhaust pipe flange on the number 5 cylinder. This failure allowed exhaust gases to melt an alternator wire, which also reduced the effectiveness of the turbocharger on the modified engine installation.