Incident Details
During a descent, the pilot reduced manifold pressure to 16 inches and trimmed the airplane for a 650 feet per minute rate of descent. The airspeed increased to about 155-160 mph indicated airspeed. The pilot stated that the aircraft was stabilized at that speed and that the air was smooth.
Pilot's Account
Without any advance warning, the ruddervators and the entire tail began to flutter. The pilot heard a "woofing" noise at approximately 1.5 to 2.0 hertz frequency, though he noted that little shaking was felt. In response, he reduced manifold pressure to idle and lowered the landing gear, attempting to minimize control movements on the tail. The flutter ceased after about five seconds, by which time the aircraft had nearly leveled off and the speed had stabilized at 120 mph.
Post-Landing Inspection
After an otherwise uneventful landing, the pilot conducted a walk-around inspection and observed extensive damage in the area of the aft empennage. The aircraft was later examined and repaired by Trim-Aire Inc. in Mexia, Texas. During the inspection, the technician found that the empennage flight controls were out of rigging limits.