What happened
On May 13, 2022, at approximately 21:00 EDT, a Messerschmitt-Bolkow-Blohm BK117 B-2 helicopter, registration N370SS, was involved in an accident at the Strong Memorial Hospital Heliport in Rochester, New York. The aircraft was operating as a Part 135 air ambulance flight.
Following a landing on the helipad, the pilot moved his left hand from the collective to the power levers while the crew entered and buckled into the aircraft. As the pilot moved the power levers to the "fly" position and began adjusting rooftop lights using the "Hat" switch, he heard a loud bang. The pilot observed the rod from the airframe-mounted wire cutter bouncing. He immediately shut down the engines and the crew exited the aircraft. There were no injuries to the pilot or the two crewmembers.
The investigation
An inspection by a Federal Aviation Administration (FAA) inspector identified damage to the main rotor blades and the wire cutter. The damage to the blades was consistent with contact with the wire cutter.
Subsequent investigations included:
- A rigging check of the flight controls, which showed no anomalies.
- A static functional test of the mast moment indicator, which showed no anomalies.
- A pre-departure test run, which showed no anomalies.
- A review of the previous 12-month and 100-hour maintenance inspections, which revealed no relevant issues regarding the flight control systems.