Pilot Report
The pilot reported that the airplane was at a cruise altitude of 12,500 feet msl on a cross-country flight when he experienced a sudden and complete loss of ruddervator control. He regained control by reducing engine power to 1,500 rpm and stabilizing the airspeed at 100 knots. Subsequently, control was accomplished via aileron and power inputs. The pilot flew to an airport about 75 miles from where the loss of control occurred. On short final for the intended runway, he lowered the landing gear, at which point the airplane entered a dive and collided with terrain about 300 yards short of the runway in a nose-low attitude, resulting in structural damage to the airframe. According to first responders, the pilot told them he encountered severe turbulence and momentarily lost control of the airplane.
Examination Findings
Examination of the airplane revealed that both ruddervators had separated from their respective stabilizer attach points at some earlier time during the flight. The ruddervators were not found at the accident site; only remnants remained attached to the hinge points on the stabilizers. Examination of the remaining pieces of ruddervator showed no evidence of preexisting cracks, fatigue, or corrosion damage, and all fracture features were consistent with overstress separations.
Radar Data
For the portions of the flight documented by radar coverage, the data indicated calculated true airspeeds routinely above design maneuvering speed (VA-132 knots), with two sustained periods at design cruising speed (VC-165 knots), and occasional periods 5 to 12 knots above VC. There was no evidence that the airplane's never-exceed speed (VNE-195 knots) was exceeded.
Meteorological Conditions
An AIRMET (Airman's Meteorological Information) for moderate turbulence was issued during the timeframe of the accident and included the route of flight.