Aircraft: Cessna Cardinal. Injuries: None. Location: Rock Springs, Wyo. Aircraft damage: Substantial.
What reportedly happened: The elevation of the airport is 6,764 feet MSL. The density altitude at the time of the accident was calculated to be 7,907 feet.
The pilot leaned the mixture to start the engine, but he did not lean the mixture prior to takeoff.
He did not remember using the Before Takeoff checklist, however, he stated that during the engine runup he observed that both magnetos dropped 50 rpm, and that he cycled the propeller three times, and each time the propeller recovered in a normal time span of between three to five seconds.
The engine was strong and smooth on takeoff and climb, but when the airplane was about 500 feet above ground and in a right turn, the engine began to vibrate and the plane started to lose altitude. The pilot made a forced landing, which collapsed the left landing gear.
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.
Probable cause: The pilot’s failure to 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 Identification: WPR11LA463
This September 2011 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it isintended to help pilots learn from the misfortunes of others.