20000507008089A

(-23) During decent from 8000 to 4000 feet the aircraft experienced a sever buffeting and a loud woofing noise in the tail section of the aircraft. He landed the aircraft uneventful. After an inspection of the aircraft the fuselage section of the aircraft was found to be damaged severely just forward of the stabilizers. (.4) the pilot stated that he reduced the manifold pressure to 16 inches, and trimmed the airplane for a 650 feet per minute rate of descent, which increased the airspeed to about 155-160 mph indicated airspeed. He said the aircraft was stabilized at that speed, and he never exceeded that airspeed at anytime. He said the flight was in smooth air also, and all of a sudden, the ruddervators and whole tail started to "flutter" without any advance warning. He said he heard a "woofing" noise at perhaps a 1.5 to 2.0 hertz frequency, but further stated that not much shaking could be felt. He said he then reduced manifold pressure to idle, lowered the gear, trying to minimize control movements on the tail. After the speed was reduced, the pilot said that the "flutter" stopped. He said the total time the "flutter" occurred was about 5 seconds. He said at that time, he had nearly leveled the aircraft, and the speed had stabilized at 120 mph. According to the pilot, after an otherwise uneventful landing, he parked the aircraft and conducted a walk-around inspection, noting that there was extensive damage in the area of the aft empennage. The aircraft was examined and repaired by trim-aire inc., mexia, Texas, and the technician at trim-aire found that the empennage flight controls were out of rigging limits.