Amateur-built Sonerai II N232PE accident near Grantsburg, Wisconsin

Probable cause

The pilot's failure to maintain airspeed during initial climb which resulted in a stall/spin. Contributing to the accident was the degraded engine performance.

NTSB analysis

The accident flight was the pilot’s first flight in the amateur-built, experimental airplane he had purchased about 7 months prior to the accident. A witness reported that the pilot was taxiing up and down the runway while revving the engine. The witness stated that the engine was missing on at least one cylinder during takeoff. He stated that the airplane climbed and made a left turn directly over his house, clearing it by about 80 feet. While in the turn, the wings dipped to the right, and then the wings dipped to the left “real hard.” The airplane rolled inverted and went down nose first. A Federal Aviation Administration airworthiness inspector examined the wreckage at the accident site. The inspection of the airplane revealed flight control continuity.The engine was a Continental O-200 series engine, but the engine data plate was missing so the exact model and serial number could not be identified. The mechanical and electrical engine controls were present. The magneto P-lead wires were still attached to the ignition switch and magnetos. There was oil in the engine and the crankshaft could rotate but not “very far.” The pilot had a history of depression, anxiety, and sleep apnea, and had been prescribed multiple medications for the conditions. The level of a prescription antidepressant found on post-accident toxicology was more than 10 times higher than expected given the pilot's prescription for the medication. He had broken his left ankle, and had surgical screws placed for the non-healing fracture a week prior to the accident. He had recently taken narcotic and over-the-counter pain medications. The pilot had not reported any of his chronic health problems to the FAA, and it is unlikely that the FAA would have approved medical certification for him had complete information been provided.

Text from the NTSB. Open the NTSB docket for CEN09LA263 for the full record.