Accident Overview
An aircraft crashed shortly after takeoff in visual meteorological conditions. The airport elevation was 5,145 feet above mean sea level, and the temperature was 86 degrees Fahrenheit, resulting in a density altitude of 7,468 feet.
Performance Chart Limitations
The Pilot's Operating Handbook included a takeoff distance versus density altitude chart with a maximum altitude of 7,000 feet. A note in the handbook stated that extrapolation of the chart above 7,000 feet density altitude is invalid.
Pilot Actions
The pilot used runway 15, which was 5,400 feet long, for takeoff. The takeoff roll was longer than usual, and the aircraft would not climb above 200 feet. Because the terrain was rising to the south, the pilot executed a forced landing in a plowed field one mile south of the airport.
Post-Accident Engine Test
After the accident, the engine was test-run. The mixture was leaned using the pilot's technique. It was found that 100 more revolutions per minute were obtained when the mixture control was leaned an additional half inch.
FAA Inspector Comment
An FAA aviation safety inspector stated that a takeoff should not be attempted if the takeoff distance cannot be determined by the charts.