CADDO MILLS, TX, USA
N147GY
Air Command International, Inc C-147A
While maneuvering during a test flight, the gyroplane impacted terrain following a loss of rotor rpm. Witnesses reported that the gyroplane departed the runway to the south and made a 180 degree turn to a northerly heading. At the mid-point of the runway, the gyroplane entered a left turn. A witness stated that he noted a decay of rotor blade speed and then observed the main rotor blades contact the tail section. A second witness stated that he heard 'rotor blades slowing down.' The gyroplane impacted terrain in a nose low attitude and was consumed by fire. The airframe and engine were examined, and no anomalies were found that would have prevented operation of the aircraft.
HISTORY OF FLIGHT On July 15, 1998, at 0745 central daylight time, an Air Command International C-147A, N147GY, amateur-built experimental gyroplane, was destroyed when it impacted terrain while maneuvering at the Caddo Mills Municipal Airport, Caddo Mills, Texas. The commercial pilot, sole occupant of the gyroplane, was fatally injured. The gyroplane was registered to and operated by Air Command International, Inc., of Wylie, Texas. Visual meteorological conditions prevailed for the Title14 Code of Federal Regulations Part 91 test flight for which a flight plan was not filed. The local flight originated from the Caddo Mills Municipal Airport, approximately 0630. A witness, who was employed as a program manager by Air Command International, Inc., was located on the airfield northwest of runway 17R when the accident occurred. He reported that he and the pilot of the gyroplane arrived at the airport together approximately 0630 to perform some "test flight maneuvers." The maneuvers were in conjunction with testing that was completed during the previous week. At 0700, the gyroplane performed a "standard" takeoff, and the pilot performed three vertical descents: one from 700 feet, one from 800 feet, and one from 1,000 feet. The program manager reported that the "aircraft performed very well without problems." At the completion of the vertical descent tests, the pilot shut down the gyroplane and added 5 gallons of fuel to the fuel tank. The gyroplane then took off from runway 17R and made a 180 degree left turn to a northerly heading. The gyroplane, while east of the runway, made another left turn at the mid-point of runway 17R. The witness stated that he then glanced at his notes, and when he looked back at the gyroplane, the "blade speed had decayed." He observed the rotor blades strike the tail section. The gyroplane then entered a nose low attitude and descended to the ground. A fire erupted and consumed the gyroplane. The program manager added that he had 2-way radio communications with the pilot throughout the entire flight, and the pilot had been relaying "performance data relating to the gyroplane." Just prior to the accident, the pilot relayed "technical information" to the program manager, which included oil temperature 220 degrees Fahrenheit and water temperature 190 degrees Fahrenheit. The pilot did not report any problems, nor did the pilot make any distress calls. A witness, who was on the phone with the program manager, reported that the program manager stated that the flights were "going well." The telephone witness further reported that he could hear "rotor blades slowing down (as if it was slowing down to a hover)." The program manager then told the telephone witness that the gyroplane had an accident. PERSONNEL INFORMATION According to FAA records on September 30, 1972, the pilot obtained a private pilot certificate, and on March 25, 1973, he obtained a commercial pilot certificate. The pilot held airplane single and multiengine land ratings, in addition to an instrument rating. On October 1, 1993, he added a gyroplane rating and was issued a certified flight instructor certificate (rotorcraft gyroplane). Additionally, on February 23, 1997, the pilot attended a flight instructor refresher clinic, which was sponsored by the Aircraft Owners and Pilots Association's (AOPA) Air Safety Foundation. According to FAA records the pilot was issued a repairman certificate (experimental aircraft builder) on September 18, 1987, for the DiGaetano Air Command 503 gyroplane, serial number 50300001. On May 19, 1994, he was issued a repairman certificate for the Les Air Inc. Air Command 582-2 gyroplane, serial number AC5822001. According to the pilot's most recent FAA medical application, dated February 25, 1997, he had accumulated a total of 2,200 flight hours, of which 25 hours were in the last six months. The program manager stated that another gyroplane instructor pilot had administered approximately 7 hours of familiarization flight training to the pilot, in the accident gyroplane, during the week prior to the accident flight. The pilot's flight logbook was not located, and total gyroplane flight time could not be verified. AIRCRAFT INFORMATION The 1995, two place, side-by-side, fully encapsulated cockpit, dual rudder, prototype gyroplane was powered by a 200-horsepower Mazda 13B (s/n 020697AC) rotary engine and a 5-bladed, 68-inch, Warp C-8956, pusher type propeller. The engine and propeller were installed new on February 1, 1997, at which time the gyroplane had accumulated 44.5 hours. The gyroplane was equipped with a 31 foot, non-powered, teetering rotor system. The gyroplane was also equipped with an altimeter, inclinometer and airspeed indicator, in addition to digital engine and rotor tachometers. An aircraft registration certificate for N147GY, which listed Air Command International as the manufacturer and owner of the gyroplane, was issued by the FAA on April 21, 1995. A Designated Airworthiness Representative (DAR) issued a temporary special experimental amateur-built airworthiness certificate with operating limitations on May 2, 1995. In accordance with the operating limitations, and as cited in the aircraft logbook, the gyroplane completed its initial 40 hours of test flights in April 1997. On May 2, 1997, the DAR issued the gyroplane a permanent special experimental amateur-built airworthiness certificate. The program manager reported that during the initial test flights, the oil temperature indication was "high." The oil cooler was remounted in a different position, and the oil temperature indicated within the manufacturer's specifications. According to the airframe logbook, the most recent condition inspection occurred on February 28, 1998, at 45.5 hours. The last entry in the airframe logbook, dated May 30, 1998, indicated that the gyroplane had accumulated a total of 56.1 hours. The program manager reported that the gyroplane had accumulated approximately 60 hours in the past three years. METEOROLOGICAL INFORMATION The program manager reported that at the time of the accident, the weather conditions at the Caddo Mills Municipal Airport were clear skies, unrestricted visibility, winds from the south at 3 mph, and a temperature of 78 degrees Fahrenheit. At 0753, the weather observation facility at the McKinney Municipal Airport (located 20 nautical miles northwest of the accident site) reported the following weather conditions: wind calm, clear skies, visibility 10 statue miles, temperature 81 degrees Fahrenheit, dewpoint 70 degrees Fahrenheit, and altimeter 29.92 inches of Mercury. WRECKAGE AND IMPACT INFORMATION The wreckage distribution path was 363 feet in length and oriented on a magnetic heading of 170 degrees. The first piece of wreckage, located at the beginning of the distribution path, was identified as a section of the left rudder. Sections of the left rudder were scattered through the east side of the accident site. The right rudder separated from the horizontal stabilizer assembly and was located 220 feet from the first piece of wreckage. The main wreckage came to rest 700 feet east of the mid-point of runway 17, on a measured magnetic heading of 190 degrees, in a grassy area. The main wreckage consisted of the cockpit, which was melted and charred, the engine, and the steel frame of the gyroplane. Fire consumed a grassy area, which measured 25 feet by 25 feet, surrounding the main wreckage. The rotor blades and rotor hub, the last pieces of wreckage in the distribution path, were located 33 feet south of the main wreckage. The rotor blades remained attached to the rotor head. One rotor blade was bent at mid-span approximately 70 degrees, and contained red and black paint transfer marks. The second rotor blade was charred as a result of the fire. The teeter bolt was secured through both rotor blades. The teeter stop plate was bent downwards, in a "U" shape. The torque tube was in place and bent downwards. The main bearing was free to rotate and did not exhibit evidence of binding. The head plates, the attaching point for the rotor head to the mast, were secure. The main bearing gear teeth were unworn. The control cables originating at the control stick mount and extending to the rotor hub were intact and continuity was established. The five propeller blades exhibited heat damage and contained soot deposits. Each blade separated at a different length. Three of the blades exhibited linear chordwise separation at 7.25 inches, 8.5 inches, and 30.5 inches, when measured from the blade root to the point of separation. One blade exhibited an uneven separation surface, which measured 30.75 inches from the blade root. The last blade separated from the propeller hub at the blade root. The left rudder was found fragmented through the accident site. Sections of the rudder were reconstructed and a 45-degree linear separation, extending through the entire rudder surface, was evident. The right rudder remained intact. The horizontal stabilizer remained attached to the airframe. The rudder cables were intact from the rudder surface attaching points to the front keel. The pilot's seatbelt was found and verified in the secured position. TESTS AND RESEARCH The engine was examined, under supervision of the NTSB Investigator-In-Charge, at Import Motorsports of Wylie, Texas. The engine crankshaft was rotated prior to disassembly, and continuity was established to the rear drive. Debris was observed throughout the engine. The debris consisted of aluminum and dirt. Oil was present throughout the entire engine. The oil pan was removed, and oil was present in the oil pan. Dirt particles and melted aluminum particles were also observed in the oil pan. The eccentric shaft oil passages appeared to be well lubricated. Each of the engine accessories remained attached to the engine case, but all were damaged by impact forces and heat. The Weber carburetor float assembly and venturi were intact and free of debris. No anomalies were noted that would have prevented engine operation at the time of the accident. MEDICAL AND PATHOLOGICAL INFORMATION An autopsy and toxicological tests were ordered and performed. The autopsy was performed by the Southwestern Institute of Forensic Sciences, Dallas, Texas, on July 16, 1998. Toxicological tests performed by the FAA Civil Aeromedical Institute at Oklahoma City, Oklahoma, were negative. ADDITIONAL DATA The aircraft was released to the registered owner.
The pilot's failure to maintain rotor rpm while maneuvering, which resulted in the main rotor blades contacting the tail section of the gyroplane.
Source: NTSB Aviation Accident Database
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