Denison, TX, USA
N95DE
Zivko Aeronautics Inc. Edge 540-T
The 2,600-hour private pilot lost control of the airplane while performing low-altitude aerobatics at a lakeside boat event. Witnesses observed the airplane in a flat spin before leveling off and impacting the water in a 30 to 45 degrees nose down attitude. Flight control continuity was established to all flight controls, and no mechanical malfunctions or anomalies were found during the investigation. The pilot was in radio contact with a helicopter that was documenting the boat event. No distress calls were received from the mishap. The pilot was wearing an emergency parachute, but did not attempt to abandon the airplane. The flight visibility was reported as 10 miles at the time of the accident.
HISTORY OF FLIGHT On July 30, 2005, approximately 1509 central daylight time, a single-engine experimental/exhibition Zivko Aeronautics Inc. Edge 540-T aerobatic airplane, N95DE, was destroyed upon impact with water while maneuvering near Denison, Texas. The private pilot, sole occupant of the airplane, sustained fatal injuries. The airplane was registered to and operated by the pilot. Visual metrological conditions prevailed and a flight plan was not filed for the 14 Code of Federal Regulations (CFR) Part 91 personal flight. The local flight originated from the Grayson County Airport (GYI), near Denison, Texas, at an unknown time. According to information obtained by a Federal Aviation Administration (FAA) inspector, who responded to the accident site, a boating event was being conducted on Lake Texoma, near the Eisenhower Marina, and numerous boats and people were in the vicinity of the marina at the time of the accident. The airplane was observed by several witnesses "performing aerobatic maneuvers at a low altitude." Witnesses reported to the FAA that the pilot had completed a hammerhead stall, and was attempting a second stall before the airplane impacted the water in a near-vertical attitude. According to the FAA, the pilot was wearing an emergency parachute, but not a helmet. Several witnesses provided the NTSB with written statements, including the following: One witness, who was the pilot of a helicopter, reported that he was orbiting over the marina at an altitude of about 500 feet above ground level (agl) with two passengers who were photographing the boat event and N95DE. The witness stated that he was in radio contact with the pilot of N95DE during the flight, and notified the pilot of N95DE that he was entering a right turn to orbit the marina. The pilot of N95DE responded that he was "climbing over the water," but did not give an exact position. No further radio transmissions were received from the pilot of N95DE. During the turn, a passenger aboard the helicopter reported observing the airplane in a "flat spin." The pilot of the helicopter leveled the helicopter and observed N95DE at an altitude of about 300 feet agl. The pilot stated that N95DE stopped spinning, and was in a wings level nose down attitude of about 30-45 degrees. N95DE continued "on a westerly heading with a high sink rate into the dock area of the marina at an angle of approximately 30-45 degrees," until it impacted the water. The witness then transmitted a "mayday" call on the local traffic frequency that N95DE had impacted the water. A second witness, who was located on a boat at the marina, reported that he had observed an "acrobatic stunt plane make several low altitude high speed passes over the marina and arriving speed boats." The witness stated that during the first pass, the airplane was approximately 80-100 feet above the treetops on the shoreline, and during the second pass, the airplane was about 150 feet above the water. A few minutes later, the witness heard the airplane again, and observed it flying downward at a "steep angle toward the marina" at an altitude of about 150 feet above the water. The airplane sounded like "the engine was at full throttle." The witness further stated that when the airplane was approximately 50-60 feet above the water, the airplane "appeared to take a steeper angle," before it impacted the water between two boat houses in a "nearly vertical" attitude. PERSONNEL INFORMATION The 51-year old pilot held a private pilot certificate with airplane single-engine land and multi-engine land ratings, and an airplane instrument rating. His most recent FAA third-class medical certificate was issued on March 22, 2004, without limitations. At this time, the pilot reported that he had accumulated 2,150-hours of flight time. A review of the pilot's logbooks from 1970 to September 15, 2004, indicated a total flight time of 2,616 hours. The most recent logbooks were not located. Friends of the pilot estimated that he had accumulated between 50 and 100 flight hours in the accident airplane. AIRCRAFT INFORMATION The Edge 540-T was an experimental single-engine, mid-wing, tailwheel-equipped, two-place airplane, serial number 2018, that was approved for exhibition aerobatic operations, and certified under 14 CFR Part 21.191 in the experimental category. The inspection records of the completed airplane after it was built, indicated that it was found to be in a condition for safe flight on November 8, 2004. A two-hour initial test flight was flown on November 30, 2004, and the test pilot signed in the logbook that the airplane was safe for operations. The airplane was constructed from a steel tube fuselage, with a composite wing, empennage, and fairings. It was fitted with a full dual flight control system, however, solo flight was restricted from the rear seat only. At the time of the accident, it was estimated that the airplane had accumulated between 50 and 100 flight hours. The airplane was powered by a modified six cylinder Textron-Lycoming IO-540 engine from Barrett Performance Aircraft, Inc., in Tulsa, Oklahoma, designated AE IO-540-X, serial number BPA 8682. The 300-horsepower rated engine was installed on N95DE on November 18, 2004, with time since overhaul (TSO) of 0:00 hours. The propeller was a three-bladed constant speed Hartzell HC-C3YR-4AX (serial number A71226B) model that was approved by the manufacturer for full aerobatic flight. METEOROLOGICAL INFORMATION At 1505, the automated weather observation system at GYI reported wind from 070 degrees at 9 knots, visibility 10 statute miles, scattered clouds at 6,500 feet, temperature 88 degrees Fahrenheit, dew point 57 degrees Fahrenheit, and an altimeter setting of 30.13 inches of Mercury. WRECKAGE AND IMPACT INFORMATION The airplane was retrieved from Lake Texoma, about 100 feet from the shoreline, on July 30, 2005, and on July 31, 2005, the wreckage was moved to the facilities of Air Salvage of Dallas (ASOD), near Lancaster, Texas, for examination by the NTSB. MEDICAL AND PATHOLICAL INFORMATION An autopsy was performed on the pilot on July 31, 2005, by the Southwestern Institute of Forensic Sciences, Dallas, Texas. The cause of death was reported as "multiple blunt force injuries." Additional toxicology tests were also performed, and the reported results were negative. Toxicology testing on the pilot was performed by the FAA's Civil Aeromedical Institute (CAMI) Forensic and Accident Research Center, Oklahoma City, Oklahoma, for carbon monoxide, cyanide, volatiles, and drugs. Test results were reported as negative. TESTS AND RESEARCH INFORMATION On August 3, 2005, at the facilities of ASOD, representatives from the FAA, Zivko Aeronautics Inc, Textron Lycoming, Barrett Precision Engines Inc., examined the engine and airframe under the supervision of the NTSB investigator-in-charge (IIC). Examination of the airframe revealed that all control surfaces, hinges, and control linkages were found within the recovered wreckage. Structural tubing throughout the fuselage was displaced. The fuselage fuel tanks remained in place, but were ruptured. Flight control continuity was established throughout the airplane. All harness attach points were found in place. The main landing gear were torn from the fuselage and were not recovered. The right wing was separated from the fuselage and was fractured into multiple pieces. The right wing spar was broken outboard of the right wing attach fitting, and the aft right wing spar was broken 12 inches outboard of the attach fitting. The right aileron was separated from its attach points, and was broken in half just outboard of the center hinge. The right aileron bellcrank was separated from the wing, however, remained attached to the control linkage. The left wing remained attached to the fuselage, however, was removed by recovery personnel for transportation to the salvage yard. The left aileron remained attached to its respective mounts, and the control linkage remained attached to the aileron. The aileron torque tube was broken aft of the forward control stick. The right elevator was broken off, and spar separated just outboard of center control attach point. The right and center elevator hinges were still attached to the elevator, but were pulled from the horizontal aft spar. The left and center elevator hinges were in place. Push rod control linkage was contiguous through both control sticks. The rudder hinges were found free and in good condition, with control cables contiguous to fuselage attach points. Examination of the engine revealed that all cylinders remained attached to the case. The top left engine mount was separated. The fuel servo and intake plenum were separated from the engine case and not recovered. The engine driven fuel pump was removed and actuated by hand. It ejected fuel from the output line, and furnished suction at the input line. The engine was rotated by hand from the vacuum pump accessory drive and valve train continuity and compression were noted on each cylinder. The left and right magnetos remained intact and were removed from the engine. The left and right magnetos had water damage. The top and bottom spark plugs were removed and examined. When compared to the Champion Aviation Check-A-Plug Wear Guide (Part Number AV-27), all spark plugs displayed signatures consistent with normal operation. The #1, 2, and 3 bottom spark plugs were broken approximately mid-length. The ignition harness was destroyed. The oil suction screen was removed and inspected; no debris was observed. The three bladed constant speed propeller hub remained attached to the engine. However, all three Hartzell propeller blades were broken off at the root and in multiple pieces. The propeller hub was removed and the propeller governor and gasket were removed. The governor arm actuated with no apparent defects. It was found in the high pitch, low RPM position. The gasket was removed and inspected; not debris was observed. The J.P. Instruments (JPI) engine data management system (EDM-900) was removed from the airplane and sent to the manufacturer JPI, Costa Mesa, California, for recorder readout on August 2, 2005. However, due to water damage to the unit, including the memory chip, data could not be retrieved. No anomalies were found during the examination that would have precluded the engine from producing power prior to impact. ADDITIONAL INFORMATION The airplane was released to the owner's representative on November 3, 2005.
The pilot's failure to maintain control of the airplane while performing aerobatics. A contributing factor was the low altitude.
Source: NTSB Aviation Accident Database
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