NTSB Identification: MIA99LA242.
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Accident occurred Wednesday, September 01, 1999 in FORT LAUDERDALE, FL
Probable Cause Approval Date: 12/04/2000
Aircraft: Sukhoi SU-29, registration: N52PB
Injuries: 1 Serious.
NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.
The pilot been doing aerobatic snap rolls. After approximately 10-15 snaps he began another. As he pulled on the stick he '...felt the ailerons brake loose.' He recovered from the snap at 2,500 feet agl. The airplane started a 20 degree to 30 degree steep descending turn to the right. He attempted to right the airplane with back stick and left rudder to no avail. He elected to make a controlled landing in a turn. About 600 feet agl the right wing went down to 90 degrees the nose then went down the same till impact with the ground. At no time did he have any directional or aileron control of the airplane. Laboratory examination of the inboard sections of the right aileron, the inboard aerodynamic compensator (spade) from the right aileron, and the outboard aerodynamic compensator from the left aileron, revealed, the in-flight loss of control was due to fatigue cracking and the subsequent fracture of the actuator lever attaching the right aileron to the control rod. In addition, the left aileron was cracked and a portion of this spar had been missing for some time. The fatigue cracking in the actuator lever from the right aileron and the rupture of the aft spar in the left aileron were precipitated by the fatigue cracking in the attachment structure of the inboard spade from the right aileron and the outboard spade from the left aileron.
The National Transportation Safety Board determines the probable cause(s) of this accident to be: an in-flight failure of the right aileron due to fatigue cracking in the attachment structure of the right inboard aerodynamic compensator, which resulted in a loss of control, a forced landing, and subsequent impact with the ground. Full narrative available
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