THE COLONY, TX, USA
N14GR
BLANTON RAF 2000
The gyroplane's main rotor blades contacted the rudder during gusty wind conditions. According to two gyroplane pilots, they were, along with the accident gyroplane pilot, each flying their own gyroplane from Caddo Mills, Texas to Fort Worth, Texas. The last time the pilots observed the accident gyroplane, it was traveling at 80 miles per hour and 800 feet above ground level, straight-and-level, towards the destination airport. The pilots reported that the wind was from the south at '20 knots and was gusty.' One pilot stated that he encountered a gust, which he estimated at '50 knots.' A weather observation facility reported that the wind was from 200 degrees at 12 knots, gusting to 19 knots. A witness saw the gyroplane flying south and observed 'things coming off.' The wreckage distribution path was 3,397 feet in length, beginning with a fragment of main rotor blade and terminating with the engine, cabin, and main fuselage frame. Fragments of rudder were found scattered between 1,162 feet and 2,852 feet from the beginning of the wreckage path. Examination of the airframe and engine revealed no anomalies that would have precluded normal operation at the time of the accident.
HISTORY OF FLIGHT On November 28, 1998, at 1500 central standard time, a Blanton Rotary Air Force (RAF) 2000 experimental amateur built gyroplane, N14GR, was destroyed when the main rotor blades struck the rudder during cruise flight near The Colony, Texas. The private pilot, who was the registered owner and builder of the gyroplane, sustained fatal injuries. Visual meteorological conditions prevailed and no flight plan was filed for the 14 Code of Federal Regulations Part 91 personal flight. The cross-country flight originated from the Caddo Mills Municipal Airport, Caddo Mills, Texas, at 1430. According to two other gyroplane pilots, they arrived at Caddo Mills with the pilot of N14GR, earlier in the day for a meeting of "The Popular Rotorcraft Association." After the meeting, they each departed in their own gyroplane. They reported that before they took off they all planned to fly to the Propwash Airport near Fort Worth, Texas, to obtain fuel. After they departed the airport, they kept each other in sight for the first 30 miles of the flight. Both pilots reported that the last time they observed the accident gyroplane, it was flying straight-and-level along the northern perimeter of Lake Lavon, at 80 miles per hour and 800 feet agl, in a southwesterly direction, directly towards the Propwash Airport. Both pilots stated that the wind was from the "south at 20 knots and was gusty." One pilot added that he encountered a gust, which he estimated was approximately "50 knots". He added that his thoughts at the time were "WOW, that was the biggest gust of wind that I have ever been hit with." An eight-year-old witness was playing outside when she heard the gyroplane. She observed the gyroplane flying from the north to the south over Hackberry Road. She stated that she observed "things coming off" of the gyroplane. Witnesses, who observed the gyroplane while driving their vehicles, stated that they heard a "loud bang" and then observed "flames" coming from the gyroplane. The gyroplane came to rest in a field, 800 feet south of Hackberry Road, and was consumed by fire. PERSONNEL INFORMATION According to FAA records, the pilot held a private pilot certificate with a single engine land rating. On November 30, 1997, the pilot added a rotorcraft gyroplane rating. The pilot's logbook revealed that he had accumulated a total of 508 hours, of which 72 hours were in gyroplanes. All of the pilot's gyroplane flight experience was accumulated in a RAF 2000. According to FAA records, on June 9, 1986, the pilot was issued an airframe mechanic certificate. On October 31, 1997, he was issued a repairman certificate (experimental aircraft builder) for the RAF 2000 gyroplane, serial number H2-96-7-265. AIRCRAFT INFORMATION The 1997 model, two place, side-by-side, fully encapsulated, gyroplane was powered by a 130 horsepower Subaru EJ-22 Legacy engine and a 3-bladed, 68-inch, Warp, ground adjustable propeller. The engine and propeller were originally installed on the gyroplane during its assembly. The gyroplane was also equipped with a 30 foot, non-powered, 2-bladed, teetering rotor system. A registration certificate for N14GY, which listed the pilot as the manufacturer and owner of the gyroplane, was issued on June 17, 1997. The gyroplane was issued a permanent special experimental amateur-built airworthiness certificate on August 1, 1997. In accordance with the operating limitations, and as cited in the aircraft logbook, the aircraft completed its initial 40 hours of test flights in August of 1997. According to the aircraft's logbook and the pilot's logbook, the gyroplane had accumulated approximately 77 hours at the time of the accident. According to the airframe logbook, the gyroplane underwent a 25 hour condition inspection on December 24, 1997, approximately 22 hours prior to the accident. The engine had accumulated approximately 80 hours at the time of the accident. Additionally, the last entry in the propeller logbook, dated September 8, 1998, indicated that the blade tips were timed and balanced at 50 hours total time. METEOROLOGICAL INFORMATION At 1453, the weather observation facility at the McKinney Municipal Airport (located 15 miles northwest of the accident site) reported the wind from 200 degrees at 12 knots and gusting to 19 knots. The visibility was 10 miles, temperature 75 degrees Fahrenheit, dewpoint 17 degrees Fahrenheit, and there were scattered clouds at 3,000 feet. WRECKAGE AND IMPACT INFORMATION The wreckage distribution path was 3,397 feet (.64 miles) in length and orientated from north to south, across Hackberry Road. The first piece of wreckage, located at the beginning of the distribution path, was identified as a fragment of main rotor blade. The first section of rudder was located 1,162 feet south of the first piece of wreckage; sections of rudder were observed for an additional 1,690 feet along the distribution path. A main rotor blade (blade tip painted black) was located 2,798 feet south of the first piece of wreckage along the distribution path. A rudder control rod was located 2,904 feet south along the distribution path, and the right side cabin door, which was located at 3,326 feet, was the last piece of wreckage prior to the main wreckage. The main wreckage came to rest 844 feet south of Hackberry Road, on a measured magnetic heading of 070 degrees, in a grassy field. The main wreckage consisted of the cockpit, which was melted and charred, the engine, a second separated main rotor blade (blade tip painted red), and the steel frame of the gyroplane. A grassy area surrounding the main wreckage area and measuring approximately 100 feet by 100 feet was burnt. The gyroplane parts and components located along the wreckage distribution path, prior to the main wreckage, were free of soot deposits and did not exhibit signatures of heat stress. Both main rotor blades were separated from the rotor hub at the blade root, and the rotor hub was fractured inboard of the blade attaching point. The rotor blade with the black tip measured 11 feet 11 inches in length. The blade was wrinkled through the entire span and delamination was observed at the trailing edge. The rotor blade with the red tip was bent in the shape of an "S." The teeter bolt was secure and the torque tube was in place. The main bearing was free to rotate and did not exhibit evidence of binding. The control cables, originating at the control stick and extending to the rotor hub, were intact and continuity was established. The rudder was originally assembled by mating two composite surfaces together. A section of the left mating surface remained attached to the rear keel, and the remainder of the rudder was found in fragments scattered through the distribution path. One fragment of the rudder's right mating surface exhibited a 45-degree linear separation. The rudder cables were intact from the front keel to the rudder. The engine was embedded 2 feet into the ground, with the rear mounted propeller and accessory gears exposed. Each of the engine accessories remained attached to the engine. The three propeller blades separated from the propeller hub. Two blades exhibited linear chordwise separations at the blade root. The remaining propeller blade separated at mid-span and exhibited an uneven separation surface. The section of engine which was extricated from the ground was free of soot deposits and did not exhibit signatures of heat stress. MEDICAL AND PATHOLOGICAL INFORMATION The pilot possessed a valid third class medical certificate, dated April 4, 1997, which stipulated that he must wear corrective lenses while exercising the privileges of his airman certificate. An autopsy and toxicological tests on the pilot were ordered and performed. The autopsy was performed by the Office of Medical Examiner of Tarrant County, Fort Worth, Texas, on November 29, 1998. Toxicological tests performed by the FAA Toxicology and Accident Research Laboratory at Oklahoma City, Oklahoma, were negative. TESTS AND RESEARCH The main rotor assembly and a section of control tube, which connected to the rotor hub, were examined at the NTSB Materials Laboratory, located in Washington D.C. The main rotor assembly was fractured near the center of the aluminum structure connecting the blades. The fracture surface exhibited fracture features and deformation patterns indicative of a "bending overstress separation." No evidence of pre-existing cracking was found. The control tube was bent and the surfaces indicated exposure to elevated temperatures. The fracture features were indicative of an overstress separation while the tube was at an elevated temperature. (See the attached NTSB Material Laboratory Factual Report for additional details.) ADDITIONAL DATA The aircraft was released to the owners representative.
The pilot's failure to maintain control of the gyroplane during cruise flight. A factor was the gusty wind condition.
Source: NTSB Aviation Accident Database
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