Learjet 24B, Helendale, Calif., Dec. 23, 2003–According to the NTSB, the Pavair Learjet, on an IFR flight plan from San Bernardino County Airport (CNO) in Chino, Calif., to Hailey, Idaho, “departed controlled flight” and crashed.

After climbing through 26,000 feet, the copilot requested a return to CNO. ATC asked if they needed to declare an emergency, but the copilot said no. In 47 seconds, the airplane descended to 24,000 feet at about 2,000 fpm. Nine seconds later, the airplane was descending through 23,000 feet at about 6,500 fpm. About 16 seconds later, while the airplane was descending at 10,000 fpm, the first officer stated, “We’re declaring an emergency now.” No further transmissions were received from the airplane. The pilot and copilot were killed.

A witness saw the Learjet flying straight and level below a high overcast layer. The airplane then pitched “nose down a little” and “straightened again.” Then the nose pitched “straight down” until it hit the ground. The witness did not notice whether the airplane was spinning, but it appeared to be intact during the descent. He saw no smoke or fire before the airplane hit and exploded into a “mushroom cloud.”

The impact crater was on the top of a ridgeline with a circular debris field measuring only about 0.3 mile in diameter.