Incident Overview
An aircraft conducting a weather deviation maneuver collided with a canyon wall near Pima Point. The pilot had reported cumulus buildups and electrical discharges with cloud tops at or above the flight level. Radar data indicated the aircraft turned north and began an unannounced descent, continuing until radar contact was lost.
Witness Observations
Witnesses reported seeing the aircraft break out of the overcast, then perform a series of random turns, climbs, and dives before impacting the canyon wall.
Weather Conditions
Thunderstorms developed along the route several hours earlier than forecast. Examination of recorded weather radar data revealed a level 6 thunderstorm with tops reaching 49,000 feet was present at the time and location of the accident. The pilot had received a DUATS briefing 4 hours prior to the accident, but there was no record of updated weather information being requested or received after that briefing.
Wreckage Examination
No evidence of mechanical discrepancies was found during the examination of the wreckage.