HISTORY OF FLIGHT On March 31, 2006, about 0920 eastern standard time, an experimental Marvin T. Eiland SparrowHawk gyrocopter, N41964, registered to American AutoGyro of Crystal River Florida, LLC, and operated by a private individual, experienced an in-flight loss of control and crashed in a pasture near Ona, Florida. Visual meteorological conditions prevailed at the time and no flight plan was filed for the 14 CFR Part 91 personal flight from Wauchula Municipal Airport, Wauchula, Florida, to Venice Municipal Airport, Venice, Florida. The gyrocopter was destroyed by impact and a postcrash fire and the commercial-rated pilot and one passenger were fatally injured. The flight originated about 0910, from Wauchula Municipal Airport. A witness reported that he, the accident pilot, and 2 other pilots were flying together in 2 aircraft to Venice, to eat. The accident pilot had departed prior to him and he then departed and proceeded to catch up with the accident pilot, who was flying between 1,000 and 1,100 feet msl. The witness who was flying at 800 msl and 65 mph reported that he was between 3/8 to 1/2 mile behind the accident gyrocopter when it began a "slight" nose-down descent. The gyrocopter lost a couple hundred feet altitude but the descent became progressively steeper to a point where it was, "unsafe diving." He did not see anything separate, nor did he see smoke trailing the gyrocopter. The nose of the gyrocopter then tucked down and the descent became vertical. He was on the same radio frequency as the accident pilot and there was no distress call from him. He witnessed the impact and subsequent explosion, flew to the accident site area where he orbited several times, then returned to the departure airport. PERSONNEL INFORMATION The pilot was the holder of a commercial pilot certificate with rating rotorcraft-gyroplane. He was also the holder of a private pilot certificate with ratings airplane single-engine land, and instrument airplane. He was the holder of a flight instructor certificate with rotorcraft-gyroplane rating issued on June 7, 2005. He was issued a third class medical certificate on March 15, 2005, with a limitation, "holder shall possess glasses for near an intermediate vision." The application for the 2005 medical indicates his total time was 1,400 hours. He was the holder of a repairman certificate for experimental amateur built aircraft. The pilot's son estimated his father had flown the accident gyrocopter approximately 175 hours between the date of his last medical certificate (March 15, 2005), and the accident date. His father's pilot logbook was in the gyrocopter, and was not recovered. The passenger was not listed in FAA records as having a pilot certificate. AIRCRAFT INFORMATION The gyrocopter was assembled by the pilot from a kit in 2004, and was listed as a model Sparrowhawk, and designated serial number H20030008K. It was certificated in the experimental category and was equipped with water-cooled, fuel injected 148-horsepower Subaru EJ 22 engine. The gyrocopter was equipped with two side-by-side seats; flight controls were equipped at each seat. Each seat was equipped with a single-point lap belt/shoulder harness. The pilot's son reported the maintenance records were also in the gyrocopter at the time in the accident; they were destroyed by the post crash fire. He estimated that his father had operated the gyrocopter for approximately 175 hours since it was built. METEOROLOGICAL INFORMATION A surface observation weather report (METAR) taken at the Sarasota-Bradenton International Airport, Sarasota Florida, at 0853, or approximately 27 minutes before the accident, indicates that the wind was from 100 degrees at 13 knots, the visibility was 10 statute miles, the temperature and dew point for 22 and 14 degrees Celsius respectively, and the altimeter setting was 30.25 inHg. WRECKAGE AND IMPACT INFORMATION Examination of the accident site by a FAA airworthiness inspector revealed the gyrocopter crashed in an open pasture; the gyrocopter was destroyed by impact and a post crash fire. Evidence indicates that the gyrocopter descended nearly vertical. An oval shaped depression measuring approximately 6 feet by 5 feet was noted in the ground. The main rotor mast was parallel to the ground, and the engine was rotated to the right approximately 90 degrees. One blade of the main rotor was bent up approximately 45 degrees at the reinforcing plate, while the other blade exhibited a 90 degree "aft hook" approximately 4 feet from the engine. The gyrocopter was recovered for further examination. Further examination of the gyrocopter was performed by a representative of the gyrocopter designer with FAA oversight. The examination revealed that the cabin section and primary structure were destroyed by fire. The pilot's (left seat) single point lap belt/shoulder harness was found connected, while the passenger's (right seat) single point lap belt/shoulder harness was found disconnected. Examination of the rotor head revealed that both pitch stop bolts were fractured at the rotor head torque tube. The aft pitch stop bolt was found "jammed between the steel spring plate and pitch swivel plate. Imprints of this bolt are found in the torque tube." The teeter bolt of the rotor head is sheared on one side of the hub bar (consistent with impact damage) and the rotor head spindle bearings were noted to rotate. Examination of the flight control system revealed all aluminum parts in the cabin were melted. The crossbar between a cyclic control sticks was bent in the center approximately 15 degrees in a downward and slightly forward direction. Several components of the flight control system could not be found or identified. The lower half of the lower vertical flight control rods were melted, but the upper control rods were bent. Examination of the horizontal and vertical stabilizer revealed all composite skins and ribs were destroyed by fire. The upper end of the vertical was still attached to the "tail support tongue, and the lower end spherical bearing had pulled out of its socket and was attached to the lower keel." Examination of the tail support revealed that the bracket that attaches the tail support to the mast was not failed. The tail support doublers were found separated at the joint of the forward and aft tail support tubes. The main rotor torque tube was retained for further examination. Examination of the engine by the FAA airworthiness inspector revealed fire and impact damage to the engine and engine accessories which precluded operational testing of the engine. The propeller remained secured to the engine. One full-span propeller blade remained secure to the hub, while the remaining 2 blades were fractured near the hub. The right camshaft was fractured just inside the "engine seal." The timing covers (plastic) were you destroyed, and both camshaft pulleys were fractured. The intake manifold was "broke/melted" and the alternator was broke from the mount. All components of the fuel and electrical system related to the engine were destroyed by fire. A section of the fractured right camshaft was retained for further examination. MEDICAL AND PATHOLOGICAL INFORMATION The pilot was found in the wreckage, while the passenger was found approximately 20 to 30 feet west of where the gyrocopter came to rest. Postmortem examinations of the pilot and passenger were performed by the District Ten Medical Examiner's Office. The cause of death for both was listed as blunt impact. The FAA Toxicology and Accident Research Laboratory (CAMI), located in Oklahoma City, Oklahoma, and also the University of Florida Diagnostic Referral Laboratories (University of Florida) performed toxicological analysis of specimens of the pilot and passenger. A note on the CAMI toxicology test for each occupant indicates the submitted specimens exhibited putrefaction. The results of analysis of specimens of the pilot by CAMI was negative for tested drugs. Testing for carbon monoxide and cyanide was not performed. No ethanol was detected in the submitted kidney specimen, while 23 (mg/dL) ethanol was detected in the submitted muscle specimen. The results of analysis of specimens of the pilot by University of Florida was positive for ethanol (87 mg/100 g), in the submitted muscle specimen. Testing for carboxyhemoglobin was not performed because the specimen was not suitable. The comprehensive drug screen was negative in the submitted muscle specimen. The results of analysis of specimens of the passenger by CAMI negative for tested drugs. Testing for carbon monoxide and cyanide was not performed. Ethanol (29 mg/dL) was detected in the submitted muscle specimen, and 17 (mg/dL) ethanol was detected in the submitted kidney specimen. The results of analysis of specimens of the passenger by University of Florida was positive for ethanol (66 mg/100 g) in the submitted muscle specimen. Testing for carboxyhemoglobin was not performed because the specimen was not suitable. The comprehensive drug screen was negative in the submitted muscle specimen. TESTS AND RESEARCH The National Transportation Safety Board Materials Laboratory located in Washington, D.C., examined the section of fractured camshaft, a bent/fracture bolt, and a 1.25 inch thick "torque tube" with remnants of 3 fractured bolts. The result of the examination of the fractured camshaft revealed a uniform grainy surface which is consistent with overload failure. The examination of the bent/fractured bolt revealed a grainy fracture surface that was consistent with bending overload. The examination of the torque tube revealed the fracture surfaces of the three bolts was consistent with bending overload. The "forward stop bolt" was threaded approximately 1 inch into the torque tube, while the "aft stop bolt" was threaded approximately 1/2" into the torque tube. Further examination of the threaded hole of the aft pitch stop revealed "clean" threads extended approximately 1/2" below the end of the bolt, and discolored threads were noted from the top of the torque tube extending approximately 1/4 inch into the torque tube. The threaded portion of the forward pitch stop bolt hole exhibited discoloration of the threads from the top of the torque tube extending approximately 1/4 inch into the hole. According to the designer of the gyrocopter, testing of an exemplar gyrocopter using the as found position of the aft pitch stop bolt (threaded approximately 1/2 inch into the torque tube) revealed that the rotor disk would have a maximum positive tilt angle of approximately 6 degrees. The manufacturer reported that the disk tilt angle at normal cruise speed is approximately 3 to 4 degrees positive, and approximately 12 degree positive disk tilt is required to make a normal landing. The main rotor disk tilt would be approximately 18 degrees positive with a properly positioned aft pitch stop bolt. A representative of the manufacturer also reports that with the aft pitch stop bolt extended an additional 1/2 inch, "the aircraft would have been able to fly with normal control inputs." During a normal descent, the nose of the gyrocopter is approximately 10-15 degrees below the horizon, and during a sudden engine-out situation, the nose of the gyrocopter is positioned approximately 30 degrees below the horizon. The 30-degree descent angle is required in order to maintain 60-65 miles-per-hour. That pitch attitude results in a typical rate of descent between 1,200 and 1,500 feet per minute. Testing of an exemplar gyrocopter was performed by placing it in a 15-degree nose-down attitude resulted in the inability to maintain seat position without being properly restrained. Testing of an exemplar gyrocopter at nose-down angles of 20 degrees and greater revealed "a person would fall forward against the cyclic control stick pushing the flight control against the forward control stop." ADDITIONAL INFORMATION The gyrocopter minus the retained components was released to David Eiland (pilot's son), on July 20, 2007. The NTSB retained components were also released to David Eiland on August 1, 2007.