# NTSB CEN12CA319: Hughes 369HS, N11ZX, Delavan, MN, May 25, 2012 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Data collection · Final report - Date: May 25, 2012, 17:35 local (22:35 UTC) - Place: Delavan, MN - Coordinates: 43.768054, -94.018333 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=43.7681&lon=-94.0183&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering-low-alt flying: Low altitude operation/event](https://openairdocs.org/ntsb-events/220) - Highest injury: Serious injuries - Injuries: 1 serious - Status: Completed, report August 15, 2012 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA -- Minneapolis Flight Standards - NTSB case key (mKey): 83754 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN12CA319 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/83754/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=83754 - Page: https://openairdocs.org/ntsb/CEN12CA319 ## Probable cause The pilot’s failure to maintain clearance with power lines during an aerial application flight. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: altitude](https://openairdocs.org/ntsb-findings/01062012): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Hughes 369HS, 2 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md?model=4470728), [All aircraft, 1,310 cases](https://openairdocs.org/ntsb-findings/01062012/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Maneuvering-low-alt flying: Low altitude operation/event](https://openairdocs.org/ntsb-events/220) (defining event); cases with it: [Hughes 369HS, 3 cases](https://openairdocs.org/ntsb-events/220/sequence.md?model=4470728), [All aircraft, 780 cases](https://openairdocs.org/ntsb-events/220/sequence.md) - [Uncontrolled descent: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Hughes 369HS, 5 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=4470728), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that he was spraying a drainage ditch when he encountered a railroad track embankment. He increased altitude to clear the tracks, but, as he descended back into the ditch on the opposite side of the tracks to continue spraying, he observed a set of power lines in his flight path. He attempted to maneuver to avoid the lines, but the left landing skid of the helicopter struck the lines. The helicopter subsequently impacted an adjacent corn field about 250 feet from the power lines. The pilot was seriously injured, and the helicopter sustained substantial damage to the fuselage and tailboom. The pilot reported that there were no failures or malfunctions related to the helicopter before the accident. ## Factual narrative The pilot reported that he was spraying a drainage ditch when he encountered a railroad track embankment. He increased altitude to clear the tracks, but as he descended back into the ditch on the opposite side of the tracks to continue spraying, he observed a set of power lines in his flight path. He attempted to maneuver to avoid the lines, but the left landing skid of the helicopter struck the lines. The helicopter subsequently impacted an adjacent corn field about 250 feet from the power lines. The pilot was seriously injured, and the helicopter sustained substantial damage to the fuselage and tailboom. The pilot reported that there were no failures or malfunctions related to the helicopter prior to the accident. ## Aircraft - Registration: [N11ZX](https://openairdocs.org/aircraft/N11ZX), registered now, S/N 640609S, built 1974 (OpenAirDocs) - Reported make and model: HUGHES 369HS - Registry model: [Hughes 369HS](https://openairdocs.org/model/hughes-369hs) (registry code 4470728) (OpenAirDocs) - Registry engine: [Allison 250-C20 series](https://openairdocs.org/engine/allison-250-c20-series) (registry code 03020, turbo-prop) (OpenAirDocs) - Category: Helicopter - Serial number: 640609S - Airframe hours: 8836.1 - Engines: Allison 250-C20 450 horsepower turbo shaft - Damage: Substantial damage - Flight: Aerial application, Part 137 - Operator: Teryjon Aviation, Inc. - Registered owner: Big Bird Leasing, Inc. - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 20, 2012, 1.7 hours before - Departed: PVT, Delavan, MN - Destination: PVT, Delavan, MN - Airport: FRM, Fairmont Municipal ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 64; injuries: serious; commercial; airplane ratings: single-engine land; medical: class 2, with waivers/limitations; last flight review July 20, 2010; seat: left; flight hours: 5,184 total, 4,684 in this make and model, 5,184 as pilot in command ## Weather - Conditions: Visual (VMC), Day - Wind: 120° at 4 knots - Visibility: 4 statute miles - Lowest ceiling: 11,000 ft overcast - Temperature: 63 °F, dew point 55 °F - Altimeter: 30.05 inHg - Observed at: FRM, 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 20120525010429A](https://openairdocs.org/incident/20120525010429A), May 25, 2012: Hughes 369HS, Delavan, MN, Substantial damage. Terry john aviation was hired to spray ditch line in Delavan,MN. While spraying ditch line heading north helicopter maneuvered up to avoid railroad bridge and… ## Docket (3 files) The files NTSB released with the investigation on June 21, 2012, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=83754. 697 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 595 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40370225&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Conversation Record -- Operator (item 2, .PDF, 48 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40370226&FileExtension=.PDF&FileName=Conversation%20Record%20--%20Operator-Master.PDF - Conversation Record -- FAA Inspector (item 3, .PDF, 53 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40370227&FileExtension=.PDF&FileName=Conversation%20Record%20--%20FAA%20Inspector-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.