Cessna 177 N3152T accident near Rock Springs, Wyoming

Probable cause

The pilot did not lean the fuel mixture prior to takeoff, which resulted in the engine's inability to attain sufficient power due to the rich mixture, and his inadequate preflight planning.

NTSB analysis

According to the pilot, he leaned the mixture in order to start the engine, but he did not lean the mixture prior to takeoff and did not remember using the Before Takeoff checklist. Shortly after takeoff and during the initial climb, the engine power was smooth and strong, but, about 500 feet above ground level, the engine started vibrating and the airplane began to lose altitude. Not being able to return to the airport, the pilot made an emergency off-field landing. During the landing roll, the left main landing gear impacted a hole or a berm, which resulted in the collapse of the left main gear. A postaccident engine run revealed no anomalies with the engine that would have precluded normal operation. The airplane’s owner’s manual notes that, for maximum rate-of-climb performance at airports above 5,000 feet, the mixture control should be leaned. The elevation of the airport was 6,764 feet. The density altitude at the time of the accident was calculated to be 7,907 feet.

Text from the NTSB. Open the NTSB docket for WPR11LA463 for the full record.