What happened
A private pilot operating a Cessna 421B departed from Montrose, Colorado, on a southbound trajectory. Radar tracking indicated that the aircraft initially climbed from 14,300 feet to 16,600 feet MSL at a rate of 1,792 feet per minute. Shortly after reaching this altitude, the aircraft experienced a sudden and severe descent, dropping 4,000 feet at a rate of 12,631 feet per minute. Following this rapid descent, the plane regained some altitude, climbing back to 13,300 feet MSL at 1,448 feet per minute, before it vanished from radar surveillance.
The aircraft subsequently crashed into snow-covered mountainous terrain. Witnesses in the area, specifically snowmobilers near the impact site, reported that visibility was reduced to less than 1/2 mile due to active snow showers.
Findings
While a pilot flying out of Telluride Regional Airport reported clear conditions at lower altitudes and encountered clouds between 12,000 and 22,000 feet MSL, they noted an absence of turbulence or icing. However, the rapid loss of altitude remains the most significant flight anomaly recorded by radar prior to the disappearance of the aircraft.