CEN19TA075

Factual narrative

On December 24, 2018, about 2215 central standard time, a Eurocopter Deutschland MBB-BK117 C-2 helicopter, N145EC, impacted a fire truck during a visual approach to a landing zone near Strum, Wisconsin. The commercial pilot and two crewmembers received minor injuries, and the helicopter was substantially damaged. The helicopter was registered to U.S. Bank and operated by Mayo Clinic under the provisions of Title 14 Code of Federal Regulations Part 135 as an air medical flight. Night visual meteorological conditions prevailed for the flight, which departed from Chippewa Valley Regional Airport (EAU), Eau Claire, Wisconsin, about 2154. The pilot reported that while on approach to a landing zone, the crew called out obstructions such as trees, fire trucks, and flag poles. About 30 ft above ground level, the pilot noticed a street sign and decelerated the helicopter, which resulted in a lowering of the tail boom and rotor. During this movement, the tail rotor contacted the hose rack on a fire truck and the helicopter started to spin. The pilot lowered the collective control and the helicopter impacted terrain, which damaged the landing gear skids. Postaccident examination revealed that the helicopter sustained substantial damage to the tail rotor. The pilot reported there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. Following the accident, the operator initiated the following actions: Reviewed current company policies regarding confined area/ scene landing to verify pilots were provided the proper guidance and training to land at a non-airport/helipad environment. Provided training to all pilots regarding expectations in these landing scenarios and steps to assist in decision making and determining the suitability of a landing area. Introduced scene landing scenarios into annual simulator training. Developed annual syllabi for pilots to complete annually to refresh themselves and medical crew on basic confined area/scene landing protocols. Developed an off-airport landing checklist that included: 1. Ensure the size of the area is adequate, 2. The landing surface is suitable. Is it level is there mud, ice, blowing snow, etc. 3. Review obstacles in or around the landing zone (wires, vehicles, flagpoles, fences, street signs, etc.), 4. The best approach direction and type of approach (Normal, steep, vertical), 5. The best departure direction and type of departure (Normal, vertical), 6. Power requirements needed to avoid obstacles. The pilot and two crewmembers were on a night air medical flight. While on approach to the landing zone with several obstructions nearby, the pilot noticed a street sign and slowed the helicopter, which lowered the tailboom and tail rotor. The helicopter's tail rotor then struck a hose rack on a fire truck, which resulted in a loss of control and impact with the ground. The helicopter sustained substantial damage to the tail rotor. The pilot reported no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation. Source: NTSB Aviation Accident Database Retrieved: 2026-02-12

NTSB Findings

FAA avdata. C = Cause, F = Factor.

• C Personnel issues-Psychological-Attention/monitoring-Monitoring environment-Pilot - C
• C Aircraft-Aircraft oper/perf/capability-Performance/control parameters-Altitude-Not attained/maintained - C
• C Environmental issues-Physical environment-Object/animal/substance-Ground vehicle-Contributed to outcome - C