The private pilot was part of a formation of four airplanes making a cross-country flight during day visual meteorological conditions over a broken-to-overcast cloud layer. During the flight, the Nanchang CJ6A, which was positioned left of the lead airplane, began drifting to the left of and behind the formation, which resulted in the lead pilot losing sight of the airplane.
The lead pilot twice asked the accident pilot if he was okay and received affirmative responses. However, the pilot in trail lost sight of the accident airplane as it dropped below and behind his airplane, and the pilot positioned to the right of the lead pilot observed the accident airplane descend in a wings level, slight nose-down attitude into clouds below and behind their position.
Despite multiple attempts, no further radio communication was established with the accident pilot.
A witness who was located near the accident site saw the airplane descend from the clouds in a near vertical attitude until she lost sight of it behind a nearby ridgeline.
Examination of the accident site near Keene, California, indicated that the airplane hit terrain in a near vertical attitude. The pilot died in the crash.
Post-accident examination of the airplane revealed no evidence of any preexisting mechanical malfunction that would have precluded normal operation.
The pilot had a history of coronary artery disease and was at an increased risk for a sudden cardiovascular event, however there is insufficient evidence to determine if his heart disease contributed to this accident.
Probable cause: The pilot’s failure to maintain airplane control following a descent into clouds.
NTSB Identification: WPR17FA091
This April 2017 accident report is provided by the National Transportation Safety Board. Published as an educational tool, it is intended to help pilots learn from the misfortunes of others.