What happened
While operating at flight level 260, the pilot of N9143B, a single-engine aircraft, requested permission to deviate approximately 12 miles to the west. This request was made in an attempt to navigate through what the pilot perceived as a gap in the weather between two distinct thunderstorm clusters. Radar tracking indicated that the aircraft was attempting to pass through a region of light radar echoes situated between two larger, more intense storm cells.
During this maneuver, the aircraft entered an uncontrolled descent. Witnesses on the ground reported hearing a winding sound from the engine before observing the aircraft emerge from the cloud layer at an altitude of approximately 300 feet. The aircraft was seen in a nose-low spiral, and the right wing had been separated from the fuselage. While the main wreckage was located at the crash site, the right wing was discovered 1.62 miles away from the primary debris field.
Prior to the accident, the pilot had obtained a weather briefing and contacted the Enroute Flight Advisory Service. The briefing had explicitly warned of thunderstorm activity and cumulonimbus clouds with tops reaching flight level 450, noting a weather system affecting the Florida Gulf Coast. The pilot had also been informed of convective SIGMET 05E for southern Florida and had been advised that a specific routing toward Tampa/St. Petersburg would be necessary to avoid the active storm cells.
Findings
Radar data confirmed that thunderstorm clusters were present near the flight path of N9143B during the descent. The pilot's attempt to utilize a perceived gap in the weather resulted in the aircraft encountering severe convective activity, leading to the uncontrolled descent and loss of the right wing.