MESSERSCHMITT-BOLKOW-BLOHM BK 117 B-2

Full Narrative

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