ROCKWELL AERO COMMANDER 690B, HOMERVILLE, GA., MARCH 27, 2003–An in-flight encounter with unforecast severe turbulence resulted in the design limits of Aero Commander 690B N53LG being exceeded an overload failure of the airframe, concluded the NTSB. The airplane was at 27,000 feet when the turbulence was encountered and the pilot called “Mayday” to Jacksonville Center. Within several seconds, the airplane accelerated from 175 knots through 300 knots groundspeed and descended to 16,500 feet. The airplane disappeared from radar coverage and crashed in a swampy area 15 miles north of Homerville. The crash debris line extended for 8,081 feet. Examination of the airframe components revealed all failures were due to overload and the airframe design limits were exceeded. Although the aircraft was on an IFR flight plan from Mount Pleasant, Tenn., to Titusville, Fla., and in IMC, the pilot did not obtain a weather briefing.
The accident site was located south of a stationary front and downstream of a low-pressure system.
