Rochester, NY, USA
N370SS
MESSERSCHMITT-BOLKOW-BLOHM BK 117 B-2
After the pilot of the air medical helicopter landed, the medical crew boarded and he prepared the helicopter for takeoff. The pilot stated that he was adjusting a light switch while his right hand was on the cyclic control when he heard a loud “bang.” He subsequently noticed that the rod from the airframe-mounted wire cutter was bouncing back and forth. The pilot then shut down the engines and the crew exited the helicopter. A postaccident examination of the helicopter revealed substantial damage to the main rotor blades that was consistent with them having contacted the wire cutter. The examinations otherwise did not reveal evidence of any anomalies of the flight control system that would have precluded normal operation. Based on this information, while the pilot indicated that he was holding the cyclic control at the time of the event, given the damage to the helicopter and the lack of anomalous findings with the flight control system, nor the existence other external influences like substantive wind, it is likely that he inadvertently moved the cyclic, which resulted in the main rotor briefly moving into a position where it contacted the wire cutter.
On May 13, 2022, about 2100 eastern daylight time, a Messerschmitt-Bolkow-Blohm BK117 B-2 helicopter, N370SS, was substantially damaged when it was involved in an accident at the Strong Memorial Hospital Heliport, Rochester, New York. The commercial pilot and two crewmembers were not injured. The helicopter was operated as a Title 14 Code of Federal Regulations Part 135 air ambulance flight. The pilot reported that he landed on the helipad and moved his left hand from the collective to the power levers. He said the crew was ready to go and entered the helicopter shortly after landing. Once the crew entered the helicopter and “buckled in,” the pilot moved the power levers to “fly,” turned the light switches on, and began to move the “Hat” to adjust the lights on the rooftop. The pilot stated that his right hand was in control of the cyclic when he heard a loud “bang” and noticed the rod from the wire cutter bouncing back and forth. The pilot immediately shut down the engines and the crew exited the helicopter. The pilot reported that the wind was light and variable at a velocity of about 3 mph at the time of the accident. Examination of the helicopter by a Federal Aviation Administration inspector revealed damage to the main rotor blades and the wire cutter. A rigging check of the flight controls was performed under the supervision of an FAA inspector, and no anomalies were noted that would have contributed accident. A static functional test of the mast moment indicator was performed, with no anomalies noted. A pre-departure test run was also performed with no anomalies. A review of the last 12-month and 100-hour maintenance inspections did not reveal evidence of any relevant maintenance to any of the helicopter’s flight control systems
An unintentional movement of the cyclic control before takeoff, which resulted the main rotor blades contacting the fixed wire cutter.
Source: NTSB Aviation Accident Database
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