# NTSB CEN21LA116: Mcdonnell Douglas Helicopter 600N, N60BK, Mankato, MN, January 22, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: January 22, 2021, 14:00 local (20:00 UTC) - Place: Mankato, MN - Coordinates: 44.166389, -94.221667 - Nearby events: https://openairdocs.org/map.md?lat=44.1664&lon=-94.2217&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: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Central Region - NTSB case key (mKey): 102558 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA116 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/102558/pdf - Page: https://openairdocs.org/ntsb/CEN21LA116 ## Probable cause The pilot’s loss of situational awareness while landing, resulting in an impact with power lines. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Workload management: task allocation](https://openairdocs.org/ntsb-findings/02064020): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Mcdonnell Douglas Helicopter 600N, 1 case](https://openairdocs.org/ntsb-findings/02064020/cases.md?model=3027377), [All aircraft, 12 cases](https://openairdocs.org/ntsb-findings/02064020/cases.md) - [Object/animal/substance: wire](https://openairdocs.org/ntsb-findings/03022032): Environmental issues › Physical environment · Awareness of condition (probable cause); cases with it: [Mcdonnell Douglas Helicopter 600N, 2 cases](https://openairdocs.org/ntsb-findings/03022032/cases.md?model=3027377), [All aircraft, 588 cases](https://openairdocs.org/ntsb-findings/03022032/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: [Mcdonnell Douglas Helicopter 600N, 1 case](https://openairdocs.org/ntsb-events/490/sequence.md?model=3027377), [All aircraft, 1,309 cases](https://openairdocs.org/ntsb-events/490/sequence.md) ## Analysis The pilot reported he had completed one line-pull in the helicopter and had gone back to the landing zone to refuel. After refueling, the pilot flew to the puller machine that was now at another structure. The rope was hooked up by the linemen as normal, but the hydraulic fluid had frozen on the puller machine and it was inoperative. The line was then unhooked by the linemen and the pilot was waved off. The pilot returned to the landing zone to wait for the puller machine to be repaired. After several minutes, the pilot heard the puller operator radio that the machine was operational, and he took off to head back to the structure. He received a second radio call that the machine was not ready, and the pilot turned and started back to the landing zone again. The pilot was concerned that the helicopter would need to be refueled again since pulls typically take about an hour. While flying parallel to the power lines and descending for landing at the fuel truck, he looked at the instrument panel timer to determine the fuel burned. As he looked back outside the helicopter, he saw the middle phase straw line and then felt the main rotor blades impact the straw line about 150 ft agl. The pilot reported the straw line is a 3/8-inch steel wire that is somewhat rusted and difficult to see in most lighting conditions. The pilot then landed near the fuel truck uneventfully. Three of the six main rotor blades were substantially damaged. The pilot reported there were no preaccident mechanical malfunctions or failures with the helicopter that would have precluded normal operation. ## Aircraft - Registration: [N60BK](https://openairdocs.org/aircraft/N60BK), registered now, S/N RN028, built 1998 (OpenAirDocs) - Reported make and model: MCDONNELL DOUGLAS HELICOPTER 600N - Registry model: [Mcdonnell Douglas Helicopter 600N](https://openairdocs.org/model/mcdonnell-douglas-helicopter-600n) (registry code 3027377) (OpenAirDocs) - Registry engine: [Allison 250-C47 series](https://openairdocs.org/engine/allison-250-c47-series) (registry code 03029, turbo-shaft) (OpenAirDocs) - Category: Helicopter - Serial number: RN028 - Year built: 1998 - Airframe hours: 7773.5 - Engines: Rolls Royce 250-C47M 808 horsepower turbo shaft - Damage: Substantial damage - Flight: External load, Part 133 - Operator: Brim Equipment Leasing LLC - Registered owner: Brim Equipment Leasing LLC - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, January 13, 2021, 20.8 hours before - Departed: Crystal Lake, MN - Destination: Mankato, MN - Equipment: ADS-B, Electronic flight bag or handheld device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 54; injuries: none; commercial; airplane ratings: single-engine land; medical: class 2, with waivers/limitations; last flight review February 28, 2020; seat: left; restraint: 4-point; flight hours: 13,100 total, 2,200 in this make and model, 12,900 as pilot in command, 75 in the last 90 days, 30 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 14 °F, dew point 1 °F - Altimeter: 30.24 inHg - Observed at: KMKT, 15 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 20210122000119A](https://openairdocs.org/incident/20210122000119A), Jan 22, 2021: Mcdonnell Douglas Helicopter 600N, Lake Crystal, MN, Substantial damage. 01-22-2021 N60BK, MD600N. Pilot (PIC) obtained aviation weather from foreflight before departing mankato MN (kmkt) airport in the morning enroute to the field… 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.