Timothy

“The most likely cause, based on the available tracking data, ATC audio, weather context, and the physics of the final trajectory, is this: The Learjet 60 penetrated the core of a strong convective cell (tops reported near 47,000 ft while the aircraft was around 35,000 ft). Inside the cell it encountered a rapid updraft-to-downdraft transition that drove the nose down. The aircraft then accelerated past its Mach limits, entered Mach tuck (the aerodynamic nose-down force that becomes strong once a Learjet is overspeed at high altitude), and developed a steep spiral. Descent rates exceeded 30,000 ft/min and the final attitude was near-vertical. Recovery was not possible once that sequence was established. Ice was reported by the crew and may have added workload or minor performance degradation, but at approximately –47 °C classic structural icing is improbable and is not required to explain the observed behavior. Claims of an isolated negative-G pushover specifically shearing the horizontal stabilizer are aerodynamically possible in severe turbulence but remain secondary and unconfirmed; the dominant, data-supported chain is cell penetration → upset → overspeed/Mach tuck → unrecoverable dive. The critical decision was the failure to deviate around a cell that was visible on radar and associated with ground stops at FLL. Once inside the core, the margin for recovery disappeared within roughly 30 seconds.”