History of Flight
On December 12, 2020, about 1523 eastern daylight time, an experimental amateur-built AR-1 gyroplane, N11TG, was substantially damaged in an accident near San Mateo, Florida. The private pilot was fatally injured. The gyroplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.
Automatic dependent surveillance broadcast (ADS-B) data showed the gyroplane departed Deland Municipal Airport – Sidney H. Taylor Field (DED) about 1350. The pilot performed two circuits in the traffic pattern before departing the pattern around 1400. After departing, the pilot maneuvered north of DED, remaining below 1,200 ft mean sea level for the remainder of the flight. At 1523:23, the ADS-B data ended about 1 nautical mile south of the accident site. The final two minutes of data showed the gyroplane descending from 950 ft msl to 725 ft msl and its groundspeed increasing from 58 knots to 76 knots. According to the kit manufacturer, the gyroplane’s general cruise speed was 47 to 86 knots.
Concerned family members contacted the Federal Aviation Administration, and an alert notice (ALNOT) was issued about 2130 for the missing gyroplane. It was located the following morning in a heavily wooded state forest with limited roads.
Wreckage and Impact Information
A review of photographs taken by first responders revealed that the gyroplane came to rest in a densely wooded area on the left side of the fuselage. The empennage remained attached. First responders reported no odor of fuel at the accident site, and during recovery, they noted the fuel tank remained intact and contained an undetermined amount of fuel. There was no evidence of fire.
Examination of the airframe confirmed continuity from the cockpit controls to the main rotor and rudder. The empennage separated from the fuselage during recovery, and the left side of the empennage was impact-separated. The main rotor remained attached, and one blade tip was impact-separated and located near the main wreckage. Chordwise scratching was noted on the blades. The two droop stops for the main rotor blades were bent downward. No anomalies with the airframe precluding normal operation were found.
Engine and Systems Examination
The engine remained attached to the fuselage. The carburetor float bowls were removed and examined. The left carburetor float bowl had yellow fuel with no anomalies noted. The right carburetor float bowl contained yellow fuel with a brown, crusty substance. Fuel from both bowls was tested with water finding paste; water was noted in the right bowl but not the left. Fuel drained from the fuel tank sump showed no water when tested. Oil and coolant were present. The engine was started using the ignition system and remaining fuel and ran up to full power with no anomalies.
The propeller blade remained attached to the engine. One of the three blades was impact-separated from about midspan; the other two were undamaged and did not display chordwise scratching.
An iFly GPS and an MGL Avionics Stratomaster Xtreme were retained for data download. Both devices turned on when power was applied, but contained no data.
The turbo control unit was downloaded at the engine manufacturing facility under NTSB supervision. It recorded eight parameters at a sample rate of about once per minute. For the accident flight, it recorded parameters beginning at 27:24 and ending at 27:41 engine hours. Starting at 27:24, engine rpm was 4,724 and throttle position 52%. At 27:25, rpm increased to 5,305 and throttle to 100%. From 27:26 through 27:41, rpm remained between 4,518 and 4,804 with throttle between 47% and 50%. At 27:41 (unknown seconds), rpm decreased to 418 and throttle increased to 92%. The final data at 27:41 showed rpm at 1,113 and throttle at 92%. Over the final three data points, airbox temperature dropped from 29°C to 24°C.