On October 13, 1998, a Stinson 108-3 (registration N569C) was involved in an aviation accident near Jackson Hole, WY. Investigators recorded the probable cause as: The pilot's inability to maintain adequate airspeed which resulted in an inadvertent stall/mush. Factors contributing to the accident were the unfavorable weather condition, mountain wave and the high density altitude. This summary draws on records from the U.S. National Transportation Safety Board (NTSB) historical archive.
A pilot reported an incident during climb near mountains, with indicated airspeed dropping to 60-65 knots and descent rate of 800-1,200 fpm despite full forward yoke. No wind was indicated by windsock.
Accident Summary
While taxiing for takeoff, the pilot observed a windsock indicating no wind and had not received a forecasted winds aloft briefing. The departure was conducted eastward toward the mountains, with the aircraft climbing at an indicated airspeed (IAS) of 85 to 90 knots. The pilot then turned the airplane to the southwest and continued climbing through 10,000 feet, corresponding to a density altitude of approximately 11,000 feet. At that point, the IAS dropped to between 60 and 65 knots.
Pilot Report
The pilot reported that the airplane began to descend at a rate of 800 to 1,200 feet per minute. He stated that despite applying full forward yoke, he could not lower the aircraft's nose. The pilot kept the wings level and reported pulling the yoke back fully close to impacting the trees.