New Braunfels, TX, USA
N77UA
Rockwell 690B
The gear in transient light remained illuminated during the initial climb. After recycling the gear and observing the light was still on, the pilot visually checked to ensure that the gear was retracted. After leveling off at 16,000 feet the pilot noticed the ball was not centered and added rudder trim to compensate. Two minutes later the airplane began to yaw and shake violently, followed by an uncommanded roll to the left of about 70 degrees with about a 10 to 15 degree pitch down attitude. The pilot manually disconnected the autopilot and reduced power. After losing 1,000 feet, control of the airplane was regained. Power was added and the airplane climbed back to 16,000 feet. After leveling off the pilot tentatively put pressure on each flight control to assess the problem and stability of the airplane. No adverse reactions to control inputs were noted, with the exception of a slight buffet approaching 200 to 210 knots. Power was then reduced to maintain a cruise speed below 200 knots. During the descent the airplane was slipping badly and the ball was all the way to the right, but the pilot was able to compensate with roll input. After a normal landing the pilot noticed the rudder horn and approximately 18 inches of the trailing rudder had separated from the aircraft. The rear of the fuselage was wrinkled on both sides of the horizontal stabilizer, and the vertical stabilizer was wrinkled. The forward one-half of the left nose gear door was bent aft approximately 90 degrees. A subsequent search for the missing top 18 inches of the trailing rudder proved unsuccessful. The top 24 inches of the remaining rudder was sectioned and sent to the NTSB Materials Laboratory Division, Washington, D.C., for examination. The Senior Metallurgist noted that the fracture surfaces observed were consistent with overstress separations. No evidence of pre-existing damage such as corrosion or fatigue was found.
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 approximately 7 nautical miles north-northwest of New Braunfels, Texas. The airplane was registered to and operated by the University of Arkansas, of Fayetteville, Arkansas. The two commercial pilots and their sole passenger were not injured. Instrument meteorological conditions prevailed, and a flight plan was filed for the 14 CFR 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. According to the Pilot/Operator Aircraft Accident Report (NTSB form 6120.1/2), the right seat pilot (pilot in command) reported the co-pilot was flying the airplane from the left seat. The pilot stated that after taking off he noticed the gear in transient light was still illuminated. He visually checked that the gear was retracted and then recycled it, but noticed the light was still on. He again visually checked to ensure the gear was retracted. The pilot stated that after leveling off at 16,000 feet "I noticed the ball [slip/skid indicator] was not centered and trimmed rudder to compensate." The pilot further stated that approximately two minutes later a violent yawing and shaking occurred, followed by an abrupt and uncommanded roll to the left of about 70 degrees with about a 10 to 15 degree pitch down. The pilot reported that he manually disconnected the autopilot due to excessive force, while simultaneously reducing power due to the nose down condition. The pilot further stated that after regaining control and adding power, he climbed back to 16,000 feet after having lost 1,000 feet. After leveling off and in straight and level flight, the pilot reported that he "tentatively" put pressure on each flight control to try and assess the problem and stability of the airplane. The pilot reported no adverse reaction to control inputs in level flight with the exception of a slight buffet approaching 200 to 210 knots. The pilot said he then decided to reduce power and maintain cruise below 200 knots. The pilot reported "during our descent the airplane was slipping badly, the ball was all the way to the right, but I was able to compensate with roll input." The pilot reported that the landing at Corpus Christi was normal, and that after parking he noticed the rudder horn and approximately 18 inches of the trailing rudder had separated from the airplane. He also reported wrinkling of the rear fuselage skin on both sides forward of the horizontal stabilizer and slight wrinkling of the vertical stabilizer. The pilot also stated the front left nose gear door was bent "with no idea of what might have happened to it." During a subsequent interview with Federal Aviation Administration (FAA) inspectors, the pilot advised them that the rudder had sustained previous damage caused by striking the top of a hangar door opening. Aircraft maintenance records indicate that the top of the rudder was repaired on February 13, 2001. A team of FAA inspectors, accompanied by two representatives from Twin Commander of Arlington, Washington, inspected the entire airplane in Corpus Christi on November 25, 2002. The team conducted a detailed inspection of the rudder, which had been previously removed from the aircraft. The inspection team concluded that without the missing portion of the rudder, it would be very difficult to evaluate the cause of the failure. The team also agreed that the damage to the nose gear door was not likely related to the cause of the accident. On February 22, 2003, a search was conducted by volunteers from the San Marcos, Texas, Civil Air Patrol to aid in locating the separated rudder. The search was conducted in a thick, dense, heavily wooded area. The result of the search effort proved unsuccessful. The top 24 inches of the remaining rudder was sectioned and sent to the NTSB Materials Laboratory Division, Washington, D.C., for examination. Results of the examination indicated that all of the fracture surfaces observed were clean and oriented on slant planes with a slightly rough texture, consistent with overstress separations. No evidence of pre-existing damage such as corrosion or fatigue was found.
The in-flight separation of the top of the rudder assembly for undetermined reasons.
Source: NTSB Aviation Accident Database
Aviation Accidents App
In-Depth Access to Aviation Accident Reports
