Accident Overview
On December 24, 2018, at approximately 2215 central standard time, a Eurocopter Deutschland MBB-BK117 C-2 helicopter (registration N145EC) struck a fire truck while conducting a visual approach to a landing zone near Strum, Wisconsin. The commercial pilot and two crew members received minor injuries, and the helicopter sustained substantial damage. The aircraft was registered to U.S. Bank and operated by Mayo Clinic under Title 14 Code of Federal Regulations Part 135 as an air medical flight. Night visual meteorological conditions prevailed, and the flight had departed Chippewa Valley Regional Airport (EAU) in Eau Claire, Wisconsin, about 2154.
Pilot Actions and Sequence of Events
According to the pilot, during the approach to the landing zone, the crew called out obstacles including trees, fire trucks, and flag poles. When the helicopter was about 30 feet above ground level, the pilot observed a street sign and decelerated. This maneuver caused the tail boom and rotor to lower. The tail rotor then contacted the hose rack on a fire truck, leading the helicopter to spin. The pilot responded by lowering the collective control, and the helicopter impacted the ground, damaging the landing gear skids.
Postaccident Findings
A postaccident examination revealed substantial damage to the tail rotor. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation.
Operator Response
Following the accident, the operator implemented several measures:
- Reviewed current company policies regarding confined area and scene landings to ensure pilots had proper guidance and training for operations at non-airport or non-helipad environments.
- Provided training to all pilots on expectations in these landing scenarios and steps to assist in decision making and determining landing area suitability.
- Introduced scene landing scenarios into annual simulator training.
- Developed annual syllabi for pilots to refresh themselves and medical crew on basic confined area and scene landing protocols.
- Created an off-airport landing checklist that included: ensuring adequate area size, checking landing surface suitability (level, mud, ice, blowing snow), reviewing obstacles in or near the landing zone (wires, vehicles, flagpoles, fences, street signs), determining the best approach direction and type (normal, steep, vertical), the best departure direction and type (normal, vertical), and power requirements needed to avoid obstacles.