20010723029209A

(-23) Purpose of the flight was to give the new owner/passenger a demonstration flight. Owner does not have any flying experience. Pilot of the aircraft is an aerobatic CFI with over 27,400 hours flight time. At least half of the 27,400 hours was flying aerobatic aircraft. The pilot had flown a mitchell wing aircraft on previous occasions. Both pilot and passenger suffered severe injuries. The outboard half of the wings of this aircraft folds back for the purpose of transporting/storing the aircraft. After unfolding and locking the extended outer wings, two qualified pilots (one being an a & p mechanic) performed a preflight inspection of the aircraft. The rudders are located on the wing tips. The aircraft wings are equipped with a pair of stabilator ailerons. Aircraft took off from a 3500-FT grass strip. Pilot stated aircraft was airborne with very little power or backpressure on the yoke. After an uneventful rotation and about 200 ft AGL, the aircraft developed an extreme vibration. Pilot stated vibration was so intense he "feared a wing might break off." Power was reduced and the vibration greatly diminished. Being concerned about the vibration, the pilot turned left to return to the field. During this turn, the left wing dropped excessively. There was a negative response from the controls during an attempt to level the wings. Pilot opted to apply more power, which resulted in the left wing dropping even more and the turn getting tighter. With what appeared to be a serious control problem, the pilot attempted to clear a stand of trees and land in an adjacent bean field. Since the left wing tip had dropped dangerously low, it struck and hung up on a tree top about 60 ft in height. This caused the aircraft to quickly spin 180 degrees and drop vertically into the trees. The outer half of both wings (aileron stabilator to the rudder) was destroyed. Because of the total destruction of both outer wings, it was impossible to determine if failure was due to a control surface failure. As previously indicated, all of the control surfaces are located on the outer wing sections. Pilot found a similar accident on the internet, which described exactly what occurred during his flight. That pilot also survived. The difference of the two accidents involved the left wing of one aircraft and the right wing of the other. It was determined the right rudder failed to return tothe neutral position. The rudder is controlled by stainless steel cable and spring tension. The rudder pivots in one direction only and is returned to neutral by spring tension. (.4) on July 23, 2001, at 1910 central daylight time, a mitchell aircraft corporation T-10, N3221X, collided with trees during an uncommanded roll after takeoff from a private grass strip, near ashland city, Tennessee. The personal flight was operated by the pilot under the provisions of title 14 CFR part 91 with no flight plan filed. Visual weather conditions prevailed at the time of the accident. The commercial rated, aerobatic certified flight instructor (CFI), and his passenger received serious injuries, and the airplane was destroyed. The flight departed the private airstrip at ashland city, Tennessee, at 1905. According to the CFI, after takeoff from the private grass strip, the CFI reported the airplane developed an "extreme vibration." He retarded the throttle and the vibration diminished. When the CFI banked the airplane to return to the private grass strip, the left wing dropped excessively. As engine power was increased to maintain a climb, the airpl ane made an uncommanded roll and began descending. The airplane collided with trees during the uncontrolled descent and impacted the ground. The post-impact examination of the airplane showed that the left rudder cable had binded in the wing and the left rudder would travel about half the normal distance. According to the CFI, during normal operation, the rudder assemblies area returned to the neutral position by spring action; the rudder assembly is designed to move in only one direction. The examination also showed that the outer half of both wing assemblies was destroyed. The wing design has the rudder assemblies installed vertically on the wing tips. The examination also nation of the airplane revealed the aileron stabilator and rudder were completely destroyed.