N261MDMauro C Dal Canto AR-1 · 2020

On December 16, 2020, about 1417 mountain standard time, an experimental, amateur built, SilverLight LLC AR-1 gyroplane, N261MD, was substantially damaged when it was involved in an accident at Heber Valley Airport (HCR), Heber, Utah. The pilot received fatal injuries. The gyroplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight.

Multiple witnesses reported observing the gyroplane take off from runway 22. One witness stated that the flight looked “incredibly unstable” the entire time it was airborne. Another witness stated that he saw the gyroplane make an abrupt pull up and a right-hand turn out, with the mast parallel with the ground if not beyond. Multiple witnesses reported the gyroplane in a spin [about the vertical axis] before pitching nose down and descending to the ground.

A video recording, taken by a witness at the airport, revealed the gyroplane began a takeoff roll on runway 22. During the roll, the left landing gear and nose wheel lifted off the runway and settled back onto the runway. Shortly after liftoff, the gyroplane pitched nose-up and down multiple times, followed by an abrupt nose-up attitude and an abrupt gain in altitude. About 3 seconds later the gyroplane banked right. Shortly after the right turn the gyroplane began to descend and rotated about the vertical axis. The gyroplane then pitched nose down and impacted terrain.

A security camera located on the airport property captured the gyroplane as it came into view while in a very nose-high attitude. The gyroplane was partially obscured from view by trees but could be seen as it leveled in pitch attitude while it descended. About 2 seconds later, away from the trees, the gyroplane rolled right to greater than 90°. About 2 seconds after that, the gyroplane pitched nose down and impacted the terrain. Two other security cameras located at the airport recorded short segments of the flight.

Automatic dependent surveillance-broadcast (ADS-B) data recorded the gyroplane as it taxied onto runway 22 at HCR. The data showed the gyroplane initially track down the center of the runway. About 1,700 ft from the beginning of the runway, the gyroplane was off the left side of the runway. About 2,200 ft from the beginning of the runway, the gyroplane turned right about 45°, followed by a left turn of about 20°. The last ADS-B data point, recorded at 1416:10, indicated the gyroplane was about 427 ft northeast of the accident site.

The gyroplane came to rest in a concrete reinforced ditch on the north side of a highway that bordered the airport property. The first point of probable impact was a gouge in the ground at the exact location as the gyroplane. Three near-parallel ground scars were present, about 15 ft from the main wreckage that were consistent with ground contact from the rotor system prior to the first impact point. A wire fence that paralleled the south side of the ditch had been pulled into the ditch by the fuselage.

According to the pilot’s son, his father owned a side-by-side gyroplane prior to the purchase of the tandem-seat AR-1. He flew the side-by-side for about 2 years then sold it. The son purchased his own side-by-side gyroplane, and his father flew with him for about a year before he purchased the AR-1. The pilot’s son stated that he never saw his father fly in a dramatic pitch up and hard right attitude as seen in the video. Medical records obtained during the investigation recorded the weight of the pilot at 143 pounds.

According to the manager of SilverLight Aviation LLC, the pilot approached him in June 2019 to inquire about building an AR-1 gyroplane. The manager stated that the owner chose to use a Rotax 915iS engine due to the high altitude at HCR and the desired better performance.

After completion of the build, the manager flew the gyroplane for a total of 6 hours, and an employee, who was a pilot and a mechanic, flew it for about 2 hours. The owner then shipped the gyroplane to HCR. The manager stated that the employee travelled to Utah to assist the owner in reassembling the gyroplane and to show him how it operated with two people. The manager indicated that the pilot was not a certified flight instructor, just a very experienced pilot.

According to the employee, he visited the pilot in Utah for 2 days to help him set up the gyroplane and to help familiarize the owner with the systems. The first day of activities consisted of practice using the prerotator and charging forward with a goal of observing the engine and rotor increasing together. No flight activities were conducted that day.

The second day of activities began about noon and involved multiple flights. The employee reported that the owner had flight performance issues that included repeated application of excessive throttle, over-controlling the gyroplane, pilot-induced oscillations, and abrupt or aggressive control inputs. The employee reported that on every takeoff he had to tell the owner to, “reduce power.” At the end of the second day, the employee reported to his employer that while the owner showed improvement with his flying skills, he still needed additional instruction and transition time in the gyroplane. The employee reported that he offered the owner additional training time, but the owner declined the offer.

According to the manager of SilverLight Aviation LLC, the pilot approached him in June 2019 to inquire about building an AR-1 gyroplane. The manager stated that the owner chose to use a Rotax 915iS engine due to the high altitude at HCR and the desired better performance.

After completion of the build, the manager flew the gyroplane for a total of 6 hours, and an employee, who was a pilot and a mechanic, flew it for about 2 hours. The owner then shipped the gyroplane to HCR. The manager stated that the employee travelled to Utah to assist the owner in reassembling the gyroplane and to show him how it operated with two people. The manager indicated that the pilot was not a certified flight instructor, just a very experienced pilot.

According to the employee, he visited the pilot in Utah for 2 days to help him set up the gyroplane and to help familiarize the owner with the systems. The first day of activities consisted of practice using the prerotator and charging forward with a goal of observing the engine and rotor increasing together. No flight activities were conducted that day.

The second day of activities began about noon and involved multiple flights. The employee reported that the owner had flight performance issues that included repeated application of excessive throttle, over-controlling the gyroplane, pilot-induced oscillations, and abrupt or aggressive control inputs. The employee reported that on every takeoff he had to tell the owner to, “reduce power.” At the end of the second day, the employee reported to his employer that while the owner showed improvement with his flying skills, he still needed additional instruction and transition time in the gyroplane. The employee reported that he offered the owner additional training time, but the owner declined the offer.

Examination of the gyroplane revealed substantial damage to the front of the fuselage including the pilot’s station. The cabin area was heavily damaged consistent with a nose-down impact.

The left vertical stabilizer exhibited substantial damage with a large section of the upper trailing edge separated, consistent with contact from the rotor system. The center vertical stabilizer exhibited substantial damage with cracking and separation of composite material along the leading edge. The top of the center vertical stabilizer exhibited a loss of material and paint consistent with contact from the rotor system. The rudder separated from the center vertical stabilizer and was located near the wreckage. The rudder exhibited substantial damage with multiple cracks on the starboard side. The port side of the rudder exhibited minor cracks.

The four-blade composite propeller exhibited separation of all four blades but at progressive distances to the hub. All four blades were recovered and exhibited minor damage to the tips, with no evidence of the propeller tips contacting vegetation or soil. The propeller damage was consistent with contact from the rotor system.

The rotor system remained attached to the mast; however, the mast separated at a fracture above the fuselage. Both rotor blades exhibited upward, chord-wise bending near their respective roots, and aft, counter-rotation bending. Some evidence of red color transfer was found on one blade, consistent with the red color of the empennage. The examination of the airframe and engine revealed no mechanical malfunctions or failures that would have precluded normal operation.

Engine performance data, recovered from the engine control unit (ECU) revealed an event log number 314 that was 5 minutes 22 seconds in duration. The event captured various engine performance data that included linear throttle position and engine speed. At 47:46 ECU time, the linear throttle position increased to 100%, and the engine speed increased to about 5,800 RPM and remained at those values for the remainder of the recorded data.

The AR-1 Pilot’s Operating Handbook stated in part:

The manual is not a substitute for competent theoretical and practical training on the operation of this aircraft. Failure to adhere to its provisions or to take proper flight instruction can have fatal consequences.

Minimum pilot weight is 144 pounds (65 Kg) in the front seat.

Maximum power at minimum takeoff weight can cause an abrupt climb rate in standard conditions that, if not corrected, may cause climb angles of greater than the placarded maximum.

Approximately 80% of maximum takeoff power is considered comfortable for a minimum weight takeoff.

Warning. Any maneuver resulting in a low-G (near weightless) condition can result in a catastrophic loss of lateral roll control in conjunction with rapid main rotor RPM decrease. Always maintain adequate load on the rotor and avoid aggressive forward control input performed from level flight or following a pull-up.