Incident Overview
On March 3, 2019, at approximately 0013 mountain standard time, a Bell 407 helicopter (registration N450AM) was substantially damaged after landing near Union Center, South Dakota. The helicopter was operated by Air Methods under 14 CFR Part 135 as an on-demand air medical flight. The pilot and flight nurse were not injured, while the flight paramedic sustained minor injuries. Dark night visual meteorological conditions prevailed, and a company visual flight rules flight plan was filed and activated.
Sequence of Events
The helicopter had departed Spearfish, South Dakota, at about 2337 and was en route to Union Center to pick up a patient. After landing at the designated landing zone, the pilot rolled the engine throttle to idle and briefed the flight crew that they were clear to depart the helicopter. Approximately 20 seconds into the engine cool-down process, a ground ambulance moved toward the helicopter, and the main rotor blades subsequently struck the top of the ambulance. The impact threw the flight paramedic to the ground.
Damage and Injuries
The helicopter sustained substantial damage to the main rotor blades, tail boom, and fuselage. The pilot and flight nurse were not injured, and the flight paramedic received minor injuries. The ground ambulance driver later stated that he saw the crew open the doors and exit the helicopter, prompting him to drive the ambulance forward to get closer. He reported that he did not realize the helicopter blades were still rotating.
Training and Procedures
Air Methods confirmed that the ambulance driver had received their training. A review of the training materials indicated that ground personnel should not approach the aircraft until the rotor blades have stopped rotating. Additionally, the training specified that ground vehicle lights should be turned off while the helicopter is landing. An excerpt from the Air Methods General Operations Manual stated that ground personnel should not come under the rotor disk until directed to do so by the pilot in command, and that the pilot will use appropriate hand signals for that purpose.