Cessna 337F N337BA accident near Frankfort, Michigan

Probable cause

The pilot intentionally attempting to take off with an inoperative engine, which lead to the airplane's inability to maintain airspeed in the initial climb, resulting in a stall and impact with trees.

NTSB analysis

The airplane was observed taxiing from the ramp to the runway with its rear engine not running and the rear propeller appearing to be feathered. The witness who observed this also saw the airplane begin its takeoff run on the runway, where it lifted off, appeared to stay low in ground effect, and then started a shallow climb. The airplane appeared very low over the trees at the end of the runway, and then appeared to stall and hit the trees. Earlier, another witness, who was preparing to depart himself, said he saw the pilot working on the airplane's rear engine. The witness stated that the pilot told him that an oil leak was coming from the flange where the oil filter attached and that it was a significant leak. The witness asked the pilot if he needed a local mechanic and the pilot explained he wanted to do the work himself. The pilot said he planned to get enough oil pressure in the rear engine to feather the propeller. The pilot stated that he planned to depart with only the front engine. An examination of the airplane wreckage and the engines revealed no evidence of any pre-impact anomalies, other than what was noted with the rear engine. A placard in the airplane stated, “Do not initiate single engine takeoff.”

Text from the NTSB. Open the NTSB docket for CEN09LA502 for the full record.