What happened
On March 30, 2019, at approximately 12:15 EDT, a Bell 2CO helicopter, registration N222ML, was involved in an accident near Montgomery, New York. The aircraft was operating under Part 91 regulations for a personal flight.
After completing a preflight inspection and boarding four passengers, the pilot departed from a concrete pad on his property. While climbing at approximately 500 feet above ground level, the pilot observed a discrepancy in the engine RPM gauges: the #1 engine needle decreased below normal operating levels, while the #2 engine needle spiked above normal levels.
Believing the #1 engine had lost power, the pilot initiated a sharp left turn to perform a run-on landing on a short asphalt surface near a utility building. During the landing, a strong wind pushed the helicopter to the left. The left landing gear contacted grass bordering a gravel strip, pulling the aircraft onto uneven ground. The helicopter stopped and subsequently tipped onto its left side, causing the main rotor to impact the ground. A small fire occurred underneath the aircraft, but all occupants were able to exit. There were no fatalities, though one passenger sustained minor injuries.
The investigation
An FAA inspector examined the aircraft at the site and found the rotor and transmission had separated from the airframe. The nose and transmission pylon area sustained substantial damage, and the upper fuselage aft of the #1 engine showed fire damage.
Post-accident examination of the throttles showed both were near the idle position. While continuity for the #2 engine throttle was confirmed, the #1 engine throttle linkage was broken, though the controls remained free to move.
Both engines were removed and tested in test cells, where they performed satisfactorily with no anomalies found that would have prevented normal operation. Investigators found the #2 engine P3 Ng speed sensor connector was disconnected; however, because the pilot reported a high RPM spike rather than a zero RPM reading, investigators determined this disconnection likely occurred during the accident sequence rather than during flight.
Calculations by the manufacturer indicated that, given the flight conditions and weight, the helicopter lacked the capability to hover in or out of ground effect, and the flight manual recommended a running landing under such conditions.