Incident Overview
An aircraft operating on a flight from West Palm Beach, Florida, to New Orleans, Louisiana, crashed into the Gulf of Mexico. Only the pilot and copilot were on board. The aircraft was en route at Flight Level 430 near the Covia Intersection on Airway J58.
Sequence of Events
About 2.5 minutes after the aircraft was reported at FL430, the Jacksonville Air Route Traffic Control Center received an unusual staccato sound transmission over the frequency. Eighteen seconds later, the copilot transmitted, "Can't get it up...it's in a spin..." Approximately 33 seconds after the initial staccato sounds, radio and radar contact with N125NE was lost about 104 miles west of Sarasota, Florida.
Search and Recovery
Floating debris were located by a search aircraft and later recovered. The flightcrew was not found. There were no known witnesses to the crash.
Probable Cause
The official probable cause was an unexpected encounter with moderate to severe clear air turbulence, the flightcrew's improper response to the encounter, and the aircraft's marginal controllability characteristics when flown at and beyond the boundary of its high altitude speed envelope, all of which resulted in the aircraft exceeding its Mach limits and a progressive loss of control from which recovery was not possible. Contributing to the accident was the disconnection of the Mach overspeed warning horn with an unauthorized cut-out switch which resulted in the absence of an overspeed warning that probably delayed the crew's response to the turbulence encounter, and the inconsistencies in aircraft flight manuals and flightcrew training programs regarding the use of spoilers to regain control.