FTW96FA151

Radar data indicated the airplane was maneuvering in a manner consistent with the performance of aerobatics prior to entering an uncontrolled descent during which it reached a speed of over 220 knots. Evidence indicated that, prior to impact, the pilot jettisoned the canopy, released his restraining harness, and deployed his emergency parachute. All of the suspension lines attaching the parachute canopy to the harness separated. The manufacturer recommended that the parachute not be deployed at speeds greater than 140 knots; however, this limit was not marked, nor was it required to be marked, on the parachute. Examination of the airplane's elevator control system revealed evidence that a bolt attaching a control tube to a bellcrank migrated out during the flight. The bolt should have been secured with a castellated nut and a cotter pin. The control tube end, bolt, castellated nut, and cotter pin were not recovered from the accident site. It could not be determined whether the bolt was improperly installed when the airplane was manufactured or had subsequently been removed and reinstalled incorrectly.

History of flight

On March 21, 1996, at 1741 central standard time, a Sukhoi SU-29, N729SU, was destroyed when it impacted terrain following a loss of control while maneuvering near New Orleans, Louisiana. The airline transport rated pilot, the sole occupant of the airplane, received fatal injuries. The airplane, co-owned and operated by the pilot, departed from Lakefront Airport in New Orleans at 1727 for the local personal flight conducted under Title 14 CFR Part 91. Visual meteorological conditions prevailed and a flight plan was not filed.

During interviews, conducted by an NTSB investigator, the co-owner and a relative reported that, during the week of the accident, the pilot had made 3 or 4 flights per day to the local practice area (approximately 7 nautical miles southeast of the Lakefront Airport) to perform aerobatic maneuvers. The pilot's intentions were to become more familiar with how the Sukhoi handled and to prepare for an upcoming air show. For these flights, the pilot occupied the rear seat and enough fuel was placed in the main tank to permit about 35 minutes of flight time.

Review of National Track Analysis Program (NTAP) and tracking radar data obtained from the Federal Aviation Administration (FAA) indicated that, after takeoff, the airplane proceeded southeast to the practice area. During the time period from 1732 to 1740, the airplane remained in the practice area and maneuvered between 3,900 and 1,800 feet MSL. At 1740:09, the airplane was at 3,400 feet MSL. The last NTAP radar return was recorded at 1740:19 and showed the airplane at an altitude of 900 feet MSL. Calculations performed using both the last two NTAP radar returns and the last two tracking radar returns indicated the airplane's average speed during the final seconds of the flight was over 220 knots (253 mph.) See the enclosed NTSB Recorded Radar Study for further details.

There were no reported witnesses to the accident. Concerned relatives of the pilot reported the airplane missing and a search was initiated at 2120. The wreckage was located approximately 10 nautical miles southeast of the Lakefront Airport at 0815 on March 22, 1996.

Personnel information

The pilot and the co-owner purchased the airplane on February 1, 1996, from Pompano Air Center (PAC), Pompano Beach, Florida. On February 1st and 2nd, the pilot received 7.5 hours of ground training and 3.4 hours of flight training in N729SU from a PAC flight instructor and, subsequently, flew the airplane from Florida to Louisiana. According to the pilot's father, at the time of the accident, the pilot had accumulated approximately 18 hours flight time in the airplane.

Prior to purchasing the Sukhoi, the pilot owned and flew other aerobatic airplanes including a Pitts S-1S. The pilot held a current Statement of Aerobatic Competency (FAA Form 8710-7) issued on December 18, 1995, for solo aerobatic flights with no altitude restriction in Pitts and Swift aircraft.

Aircraft information

The single-engine, tandem two-seat aerobatic airplane was manufactured on April 11, 1994, by Advanced Sukhoi Technologies (AST), Moscow, Russia. The airplane was assembled and test-flown in Russia, then partially disassembled (empennage, wing, and landing gear) for the purpose of shipping. The disassembled airplane was shipped to PAC, which is the worldwide distributor of Sukhoi aerobatic airplanes. At PAC, the airplane was reassembled and application was made to the FAA for a special airworthiness certificate in the experimental category for the purpose of exhibition.

An entry in the airframe logbook dated October 17, 1995, stated the following:

Aircraft re-assembled after shipment from russia. Flight control rigging checked. Brakes bled. Fuel systems leak checked. All procedures conducted in accordance with sukhoi SU-29 maintenance manual. "I certify that this aircraft has been inspected and is in a condition for safe operation."

The experimental airworthiness certificate was issued on October 19, 1995. An entry in the airframe logbook dated February 1, 1996, indicated that a Russian communications radio was removed and a transponder, encoder, navigation/communication transceiver, and navigation indicator were installed. There were no further entries in the logbook.

During an interview, conducted by the investigator-in-charge, the co-owner was questioned about maintenance performed on the airplane after its purchase from PAC. He reported that the only maintenance he was aware of involved an incident in which the pilot had experienced an in-flight restriction of control stick travel. After making an uneventful landing, the pilot, who was an FAA-certificated mechanic, examined the airplane's control system and found that a radio had slid from its case and was interfering with the controls. The pilot secured the radio with safety wire and reported no further problems with the control system. According to the co-owner, at the time of the accident, the airplane had accumulated approximately 20 hours flight time.

The elevator control system of an SU-29 consists of tubes, a bellcrank, and intermediate joints that connect the control sticks to the elevator for pitch control (see enclosed diagram). The bellcrank, which mounts directly behind the rear seat, is oriented vertically, and tubes are attached to the bellcrank in the fore and aft directions. Bolts, secured with castellated nuts and cotter pins, are used to attach the tubes to the bellcrank's clevis tangs. The lower tube runs forward and connects the bellcrank to the aft cockpit control stick. The upper tube runs aft and connects at a hanging bracket to another control tube which connects to the elevator.

Wreckage and impact information

The accident site was in a sparsely wooded swamp approximately 29 degrees 57.8 minutes north latitude and 89 degrees 53.1 minutes west longitude at sea level elevation. All wreckage was located within approximately 90 feet of the central impact crater. The water-filled crater measured about 10 feet in diameter and was flanked on the west by fragmented pieces of the left wing and on the east by fragmented pieces of the right wing. The elevator tips were embedded in the mud on the north edge of the crater with the left elevator tip located west of the right tip. During excavation of the crater, the pilot's body and fragmented pieces of the airplane were recovered from depths of 15 to 24 feet. Recovered parts included major portions of the wing, empennage and fuselage, both main landing gear, propeller blade fragments, and pieces of the engine exhaust system. Among the parts not recovered were the engine, the front and rear cockpit instrument panels, and the radios.

On March 28 and 29, 1996, a wreckage reconstruction, supervised by the NTSB investigator-in-charge, was performed. Examination of the recovered portions of the wings and empennage did not disclose any evidence of preimpact structural failure or separation. A layout of the recovered portions of the fuselage revealed that the front cockpit was destroyed and the rear cockpit sustained substantial deformation. The front seat was destroyed; however, the rear seat remained intact and attached to its anchor points. Damage to the rear seat was confined to the upper left quadrant of the seat back which was penetrated and deformed. The front 5-point restraining harness was fastened and the rear harness was unbuckled. The airplane's canopy, which is designed to be jettisoned by the pilot during an emergency bail out, was not recovered from the accident site.

The elevator control system tubes were broken in numerous places. The bolted connections in the elevator control system remained secure with the exception that the upper (aft) tube was detached from the elevator bellcrank. There was no visible bending of the upper clevis tangs of the bellcrank and no visible deformation of the