On October 20, 1991, a North American NAVION (registration N8560H) operated by Dean S. Emerson was involved in an aviation accident near Denison, TX. Investigators recorded the probable cause as: The failure to clear the power pole was due to performance calculations that did not account for the uphill slope and the use of a sod runway surface. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
An aircraft failed to establish an adequate climb after departing a 1,500-foot sod strip, resulting in a collision with a power pole.
What happened
During a takeoff attempt from a 1,500-foot sod runway featuring an uphill slope, the aircraft failed to achieve an adequate climb following initial liftoff. While the aircraft successfully cleared 20-foot trees located at the end of the runway, it struck a power pole crossbar and wires measuring 30 feet in height. The collision occurred 1,800 feet from the departure end of the runway.
The takeoff was conducted in calm wind conditions. According to performance data for the existing environmental conditions, the aircraft required an 875-foot ground run and 1,775 feet to clear a 50-foot obstacle. The pilot later reported that, given the opportunity to repeat the event, he would not have attempted the takeoff under those specific conditions.
Probable cause
The failure to clear the power pole was due to performance calculations that did not account for the uphill slope and the use of a sod runway surface.