Accident Overview
On August 11, 2020, at about 0815 central daylight time, a Rotorsport UK LTD MTOsport 2017 gyroplane, registration N615MW, was substantially damaged during a forced landing near Springfield, Tennessee. The pilot and passenger were not injured. The flight was conducted under Title 14 Code of Federal Regulations Part 91 for personal purposes.
Pilot Account
According to the pilot, the gyroplane was loaded 8 lbs below its maximum allowable gross weight when he taxied for an intersection takeoff from runway 4 at Springfield-Robertson County Airport (M91). About 2,300 ft of the 5,505-ft runway remained. At 45 knots, the pilot lifted the nose, and the gyroplane lifted off. He accelerated in ground effect to reach a planned climb speed of 55 knots, but the gyroplane would not accelerate past 48 knots. The throttle was fully advanced with no indication of engine malfunction.
As the gyroplane attained an airspeed within the published best-angle-of-climb range (45 to 50 knots), the pilot continued the takeoff. Approaching the airport boundary, the gyroplane had climbed to about 50 ft and was not accelerating. The pilot chose to perform a forced landing between the airport boundary fence and a road to avoid powerlines. During landing, the gyroplane “bounced hard and rolled left,” resulting in substantial fuselage damage.
Performance Data and Video Evidence
The pilot provided performance planning information based on weight and atmospheric conditions, indicating a takeoff roll of about 400 ft and 1,813 ft to clear a 50-ft obstacle. However, surveillance video and GPS data showed the gyroplane accelerated to a maximum ground speed of 40 knots and was about 10 ft above the runway surface at the point where it should have been in a steady-state climb. From that point, about 400 ft of runway and 1,200 ft of turf overrun remained.
Examination and Engine Test
FAA inspectors examined the gyroplane at the scene and confirmed flight control continuity. An engine run using the gyroplane’s battery and fuel system started immediately, accelerated smoothly, and ran continuously. The pilot reported no mechanical deficiencies in the NTSB Form 6120.1.
Pilot’s Theory and Comments
The pilot provided charts comparing predicted and actual performance, theorizing that published performance data might be inaccurate. He noted over 2,000 takeoffs and landings in the previous six months in two AutoGyro gyroplanes, mostly solo at 100 to 230 lbs below max gross weight. He expressed concern that this experience may have masked a performance deficiency of the MTOS-2017 with Rotax 912ULS 100hp engine and HTC prop.
In a telephone interview, the pilot regretted the intersection takeoff, stating he became complacent due to accustomed 400-ft ground runs. He later retracted the word “complacent,” suggesting that confidence from solo flights may have adversely affected performance expectations with a passenger near max gross weight.
Manufacturer’s Statement
According to Rotorsport’s Chief Compliance Officer, who performed factory flight tests on the MTOsport 2017 with Rotax 912ULS and HTC prop, evaluations were recorded via a datalogger and deemed accurate. A proprietary flight test report addendum stated that flight testing with the 914UL engine was summarized under RSUK0384, while the addendum summarized comparative tests for the 912ULS engine.
Pilot’s Recommendation
In the NTSB Form 6120.1 safety recommendation section, the pilot wrote that the accident would not have occurred if he had chosen the full 5,500 ft runway instead of the over 2,200 ft remaining from the intersection takeoff.
Advisory Handbook References
According to the FAA Rotorcraft Flying Handbook, planning an abort decision at various stages of takeoff ensures the gyroplane can be safely stopped if needed. The FAA Airplane Flying Handbook advises pilots to identify a point on the runway where the aircraft should be airborne; if not airborne, discontinue the takeoff.