What happened
While cruising at 7,000 feet, the pilot of 1O6JG requested a descent to 5,000 feet. During this period, air traffic control observed the aircraft ascending to 7,500 feet. The pilot subsequently radioed that the gyros were out. Radar tracking indicated a sudden and extreme descent, with the last return showing the aircraft at an altitude of 900 feet, descending at a rate of approximately 11,143 feet per minute.
The investigation
Examination of the wreckage revealed that the right wing, vertical stabilizer, and the stabilator had separated from the aircraft during flight due to overstress. Weather and tracking data indicated that at the time of the pilot's radio transmission regarding the gyros, the aircraft was penetrating intense to extreme weather echoes (level 5 to level 6). These thunderstorms contained heavy rain, instrument meteorological conditions, updrafts, downdrafts, horizontal gusts, and turbulence of at least moderate intensity.
Prior to the flight, the pilot had contacted the Automated Flight Service Station to request weather along the route. The specialist reported low levels of precipitation with thunderstorm activity. There was no evidence that the specialist provided the pilot with forecasted adverse weather conditions. Furthermore, there was no evidence that the Miami Air Route Traffic Control Center controller advised the pilot of pertinent weather information visible on the radarscope. Investigators found no evidence to indicate that the gyros had failed or malfunctioned.