20021101031219A

(.19) On November 1, 2002, approximately 1550 central standard time, a rockwell 690B twin-engine airplane, N77UA, sustained substantial damage after the top portion of the airplane's rudder separated during cruise flight. The airplane was registered to and operated by the university of Arkansas, of fayetteville, Arkansas. The commercial pilot and his two passengers were not injured. Instrument meteorological conditions prevailed, and a flight plan was filed for the 14 code of federal regulations part 91 corporate flight. The cross-country flight originated from the austin-bergstron international airport, austin, Texas, at 1530, and was destined for the corpus christi international airport, corpus christi, Texas. In a telephone interview with the NTSB investigator-in-charge, the pilot reported that he was in level cruise flight at 16,000 feet and noticed that the "ball was not centered." The pilot stated that "1 to 2 minutes after adjusting the rudder trim, the airplane experienced a violent yawing and shaking event, then went into an uncommanded roll to the left of approximately 70 degrees bank and 10 to 15 degrees nose down pitch with the autopilot engaged, lasting for 10 to 15 seconds." The pilot stated that he disconnected the autopilot and regained control of the airplane after losing approximately 1,000 feet. He climbed back to his assigned altitude of 16,000 feet and proceeded to his destination. The pilot further reported that "at cruise altitude, subsequent to the event, the airplane had a noticeable tendency to 'buffet,' similar to being in 'light chop' when the airspeed was less that 200 knots indicated airspeed." The pilot stated that during descent the ball was fully deflected to the right; "however, I corrected with aileron and the aircraft was under control, although in a slipping attitude." The pilot reported the approach and landing to the destination airport was uneventful. After landing, the pilot surveyed the damage and reported the top 8 to 10 inches of the top of the rudder had separated from the airplane, the rear of the fuselage was wrinkled, and the left gear door was bent back 90 degrees. The pilot also reported that during climb out, and through the entirety of the flight preceding the event, the gear in transient light remained on. (-23) shortly after leveling off at a cruise altitude of 16,000 feet, the aircraft made a hard uncommanded turn to the left and lost approximately 1,000 feet of altitude before the pilot was able to regain control. Post flight inspection revealed that the top portion of the rudder including the rudder cap and approximately six inches of the rudder skin were missing. Maintenance records revealed previous damage history in this area which may have contributed to the failure.