Flight Details
According to the pilot, after departure for a nearby airport, the landing gear was raised but the 20-degree flaps were not retracted per the after-takeoff checklist. The airplane climbed to approximately 2,400 feet in heavy rain when the pilot noticed the right engine losing power. The propeller was feathered as engine power dropped to 40 percent, but the flaps remained extended.
Engine Issue
Weather shortly before the accident reported scattered clouds at 500 feet and a broken layer at 1,200 feet. The pilot advised air traffic control (ATC) that he would attempt an ILS approach if altitude could be maintained. After maneuvering and reporting an inability to maintain altitude, the pilot descended to a right base leg. At about 1/4 nautical mile from the runway, the airplane was approximately 300 feet above ground.
The left engine was running at high speed when firefighters arrived. The right engine propeller was observed in the feathered position. Subsequent examinations revealed the right engine operated normally in a test cell with no noticeable power loss. No determination was made regarding the in-flight power loss, though rain ingestion was considered possible.
Approach and Landing
The pilot completed the landing with touchdown about 6,200 feet down the 8,000-foot runway, the airplane heading approximately 20 degrees left of the runway centerline. It then veered off the left side and went through an airport fence.
Performance Analysis
Performance calculations indicated that with the landing gear up, proper single-engine power and airspeed, and flaps retracted, the airplane could climb at about 650 feet per minute. Even with flaps at 20 degrees, a 350 feet per minute climb was possible. In either case, unless improperly configured, there was no reason the airplane could not maintain the altitudes needed for a stabilized approach.
Probable Cause
The probable cause was the pilot's improper configuration of the airplane following an engine shutdown, resulting in a low-altitude, unstabilized approach. Contributing to the accident was a loss of engine power for undetermined reasons.