# NTSB CEN19TA075: MBB BK117, N145EC, Strum, WI, December 25, 2018 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Final report - Date: December 24, 2018, 22:15 local (Dec 25, 2018, 04:15 UTC) - Place: Strum, WI - Coordinates: 44.54972, -91.391387 - Nearby events: https://openairdocs.org/map.md?lat=44.5497&lon=-91.3914&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490) - Highest injury: Minor injuries - Injuries: 3 minor - Status: Completed, report June 29, 2020 - Report: Approved by Office Director - NTSB office: Central Region - Parties: Flight Standards District Office - NTSB case key (mKey): 98928 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN19TA075 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/98928/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=98928 - Page: https://openairdocs.org/ntsb/CEN19TA075 ## Probable cause The pilot's failure to maintain clearance from the fire truck. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Attention/monitoring: monitoring environment](https://openairdocs.org/ntsb-findings/02021545): Personnel issues › Psychological · Pilot (probable cause); cases with it: [All aircraft, 809 cases](https://openairdocs.org/ntsb-findings/02021545/cases.md) - [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md) - [Object/animal/substance: ground vehicle](https://openairdocs.org/ntsb-findings/03022025): Environmental issues › Physical environment · Contributed to outcome (probable cause); cases with it: [All aircraft, 132 cases](https://openairdocs.org/ntsb-findings/03022025/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing: Collision during takeoff/land](https://openairdocs.org/ntsb-events/490) (defining event); cases with it: [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md) ## Analysis 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. ## 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. ## Aircraft - Registration: N145EC (not matched to a registry record) - Reported make and model: MBB BK117 (C2) - Category: Helicopter - Serial number: 9181 - Year built: 2008 - Airframe hours: 6055 - Engines: Turbomeca Arriel 1E2 790 horsepower turbo shaft; Turbomeca Arriel 1E2 790 horsepower turbo shaft - Damage: Substantial damage - Flight: Part 135 - Operator: Mayo Clinic, doing business as Mayo Clinic - Registered owner: U.S. Bank - Airworthiness certificate: Standard, Transport - Last inspection: AAIP, December 24, 2018 - Departed: EAU, Eau Claire, WI - Destination: Strum, WI - Flight plan: Company VFR - Equipment: Auto-pilot, ADS-B, Video recording device, Satellite tracking device, Onboard weather, Electronic primary flight display, Electronic multifunction display, Data recorder ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 52; injuries: minor; commercial; instrument ratings: helicopter; medical: class 2, with waivers/limitations; last flight review October 22, 2018; seat: front; restraint: 5-point; flight hours: 3,842 total, 1,064 in this make and model, 3,842 as pilot in command, 42 in the last 90 days, 9 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Night - Wind: calm - Visibility: 10 statute miles - Temperature: 18 °F, dew point 12 °F - Observed at: KEAU, 19 nm away ## FAA reports on this event (1) The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs). - [Accident 20181224021969A](https://openairdocs.org/incident/20181224021969A), Dec 24, 2018: Eurocopter Deutschland Gmbh MBB-BK 117 C-2, Strum, WI, Substantial damage. On December 24, 2018, an Airbus industries BK145EC registration N145EC operated by the mayo clinic a part 135 operator flew from eau claire WI, (keau) to… ## Docket (1 files) The files NTSB released with the investigation on December 9, 2019, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=98928. 823 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 823 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40478805&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.