# NTSB CHI94LA191: Hiller HU-12E, N330CW, Watertown, SD, June 23, 1994 - Type: NTSB accident investigation - Classification: Accident · Fatal · Limited investigation · Final report - Date: June 23, 1994, 11:55 local (16:55 UTC) - Place: Watertown, SD - Coordinates: 44.909931, -97.160018 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=44.9099&lon=-97.1600&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: Fatal - Injuries: 1 fatal - Status: Completed, report February 14, 1995 - Report: Approved by Office Director - NTSB case key (mKey): 9560 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CHI94LA191 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/9560/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=9560 - Page: https://openairdocs.org/ntsb/CHI94LA191 ## Probable cause the pilot's failure to maintain a visual lookout. A factor associated with the accident was the powerlines. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight collision with object, maneuvering - aerial application - object - wire,transmission (contributing factor) - clearance - not maintained, pilot in command (cause) - In flight collision with terrain/water, descent - uncontrolled ## Analysis WHILE MANEUVERING DURING AERIAL APPLICATION THE HELICOPTER IMPACTED A TRANSMISSION WIRE AND THE TERRAIN. A SUBSEQUENT EXAMINATION OF THE HELICOPTER REVEALED NO PRE-EXISTENT ANOMALIES. POST MORTEM EXAMINATION OF THE PILOT REVEALED NO PHYSICAL IMPAIRMENT AND TOXICOLOGICAL EXAMINATION OF SPECIMENS FROM PILOT WERE NEGATIVE FOR DRUGS SCREENED. ## Factual narrative On June 23, 1994, at 1155 central daylight time, a Hiller HU-12E, N330CW, registered to Emerald Helicopters, Inc., of Olivia, Minnesota, and piloted by a commercial helicopter pilot, experienced a wire strike and impact with the terrain while maneuvering during aerial application. The helicopter was destroyed and the pilot sustained fatal injuries. The 14 CFR Part 137 flight was operating in visual meteorological conditions. No flight plan was on file. The exact location of the departure and time of departure are unknown. The helicopter was involved in aerial application. A witness described hearing a "snap" followed by a noise that sounded like "thunder" and saw flames 30 feet high. An examination of the wreckage area revealed small pieces identified as being from the helicopter under nearby electrical transmission wires. No pre-existent mechanical anomalies were found on examination of the helicopter. There was no evidence of fire prior to impact with the terrain. A post mortem examination completed by the Department of Pathology, Prairie Lakes Health Care Center, Watertown, South Dakota, of the pilot revealed no pre-existing anomalies. The toxicological examination of specimens from the pilot were negative for ethanol and the drugs screened. ## Aircraft - Registration: [N330CW](https://openairdocs.org/deregistered/N330CW-2013-02-25), registration cancelled 2013-02-25, S/N HA3064, built 1977 (OpenAirDocs) - Reported make and model: HILLER HU-12E - Registry model: [Hiller UH-12E](https://openairdocs.org/model/hiller-uh-12e) (registry code 4360122) (OpenAirDocs) - Registry engine: [Lycoming VO-540 series](https://openairdocs.org/engine/lycoming-vo-540-series) (registry code 41534, reciprocating) (OpenAirDocs) - Category: Helicopter - Serial number: HA3064 - Airframe hours: 4363 - Engines: LYCOMING VO-540-C2A 305 horsepower reciprocating - Damage: Destroyed - Fire: On-Ground - Flight: Aerial application, Part 137 - Registered owner: Emerald Helicopters, Inc. - Airworthiness certificate: Special, Restricted (Special) - Last inspection: Annual, May 2, 1994, 45 hours before - Destination: NONE ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 25; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: left; toxicology performed; flight hours: 1,100 total, 215 in this make and model, 990 as pilot in command, 5 in the last 90 days, 5 in the last 30 days, 10 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 330° at 8 knots - Visibility: 15 statute miles - Lowest ceiling: 8,000 ft broken - Temperature: 75 °F, dew point 64 °F - Altimeter: 29.00 inHg - Observed at: ATY ## 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 19940623017109A](https://openairdocs.org/incident/19940623017109A), Jun 23, 1994: Hiller UH12E, Watertown, SD, Destroyed, 1 fatal. Struck wires maneuvering for a spray run. Crashed and burned. ## Docket (4 files) The files NTSB released with the investigation on June 5, 1995, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=9560. 454 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 279 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40413141&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Witness Statements (item 2, .PDF, 45 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40413142&FileExtension=.PDF&FileName=Witness%20Statements-Redacted.PDF - Toxicological Reports (item 3, .PDF, 85 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40011748&FileExtension=.PDF&FileName=Toxicological%20Reports-Master.PDF - Photo 1. Helicopter Foreground. Arrow Indicates Wires Contacted. (item 4, .PDF, 45 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40011749&FileExtension=.PDF&FileName=Photo%201.%20Helicopter%20Foreground.%20%20Arrow%20Indicates%20Wires%20Contacted.-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.