Cessna 182C N9040T accident near Stockton, California

Probable cause

The pilot's failure to secure the airplane before pulling the propeller to start the engine.

NTSB analysis

The pilot said he had tried to start the airplane's engine, but the battery seemed weak. He decided to pull the propeller by hand a revolution or two to get more oil/lubricant to the cylinders, rings, and valve stems. He explained to his non-pilot passenger that he was not going to start the engine, but mechanically lubricate it for an easier start. He stated that he turned the master off, and he believed that he turned the magnetos off. He did not set the parking brake or block the tires. After the propeller was turned 1 to 1.5 revolutions, the engine started. The airplane lurched forward and the pilot was unable to get into it. The airplane crossed a taxiway and a runway before it encountered soft earth and nosed over. The engine was pushed aft, wrinkling the fuselage, the right wing lift strut was bent, the right wing displayed wrinkles, and the aft section of the fuselage was bent and wrinkled.

Text from the NTSB. Open the NTSB docket for WPR11CA174 for the full record.