Custer State Park Airport
Aircraft Accident/Incident Report

Custer, South Dakota 57730
Friday, September 8, 2000 8:20 MDT

A witness watched the airplane take off on runway 33 (4,000 feet by 50 feet, dry asphalt) at the Custer State Park Airport (3V0). "About halfway down the runway, he got airborne. He then pushed the nose over, as if he was trying to pick up more airspeed." The witness said he keyed his microphone and asked the pilot, "You got trouble there?" The pilot responded, "No, just a little trouble climbing." The witness called the pilot again and said, "Turn into the wind, if you think it will help you out." The witness said that the pilot's response back was something like, "I got my hands full right now. Don't call me back." The witness said he watched the airplane until it went around the edge of a ridge beyond the end of the runway, where he lost sight of it. "A few minutes later, I saw smoke coming over the ridge." Several witnesses at a campground in the park saw the airplane flying westbound through the canyon along the state park road. One witness said the airplane was below the tops of the mountains and trees making up the canyon walls. Another witness saw the airplane bank hard to the left. "While banking the turn, his right wing was way up and his left wing tipped ... close to [the] ground." The witness said the next thing he realized, the airplane had crashed. An examination of the airplane wreckage revealed no anomalies. The temperature and altimeter for the Custer County Municipal Airport, (field elevation 5,602 feet), 11 miles southwest of the accident site, were 60 degrees F and 29.95 inches of Mercury, respectively. 3V0 rests in a valley at a field elevation of 3,980 feet. The terrain rises off the end of runway 33 into a 4,400-foot ridge, 1.4 miles north of the airport. A second 4,800-foot ridge, forming the north side of a canyon, begins 4 miles north of the airport. The canyon runs east to west and is characterized by steep walls and sharp turns. A fire fighter pilot at 3V0 said the winds were out of the west at 20 knots. The fire fighter pilot said that runway 33 slopes uphill, and that the winds coming off the hills to the west present difficulties to airplanes that don't have the power to climb. "We takeoff on 33 and settle over the valley there. If you keep going, you get into rising terrain and then into the canyon. If you can't climb there, it's done." The results of FAA toxicology testing of specimens received from the pilot showed the presence of 0.85 (ug/ml) cyanide in the blood. Normal blood cyanide concentrations are less than 0.15 ug/ml, while lethal concentrations are greater than 3 ug/ml. Entering the "Climb Speeds and Rates vs. Standard Altitude" chart in the airplane's Owner's Handbook with a density altitude of 7,001 feet, provides a rate of climb of approximately 315 feet per minute.

The pilot not maintaining clearance from the tree. Factors relating to this accident were the pilot's inadequate preflight planning and preparation, the high density altitude, the inadequate rate of climb, the pilot's improper in-flight decision to fly into rising terrain, the rising terrain, the blind canyon, and the tree.