# NTSB DEN03LA092: Hiller UH-12E, N508SQ, Cheyenne, WY, May 30, 2003 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: May 30, 2003, 09:00 local (15:00 UTC) - Place: Cheyenne, WY - Coordinates: 41.040279, -104.884719 - Nearby events: https://openairdocs.org/map.md?lat=41.0403&lon=-104.8847&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report February 5, 2004 - Report: Approved by Office Director - Parties: FAA FSFO - NTSB case key (mKey): 57084 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN03LA092 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/57084/pdf - Page: https://openairdocs.org/ntsb/DEN03LA092 ## Probable cause the pilot's failure to maintain aircraft control. A contributing to the accident was the sudden tailwind encountered. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - In flight encounter with weather, maneuvering - aerial application - weather condition - tailwind (contributing factor) - aircraft control - not maintained, pilot in command (cause) - In flight collision with terrain/water, maneuvering - aerial application - terrain condition - ground ## Analysis According to the pilot, he was spraying vegetation along the railroad. He was reversing course for a second application pass and began a "cyclic climb/ag turn" when he encountered a gust of wind, "approximately 15-20 miles per hour," from his "6 o'clock position." The pilot stated he was unable to recover before he hit the ground. Subsequently, the helicopter rolled on its right side, and the main rotor blades separated. Approximately 11 minutes after the accident, winds in the area were reported as 320 degrees at 12 knots with gusts to 17 knots. ## Factual narrative On May 30, 2003, at approximately 0900 mountain daylight time, a Hiller UH-12E helicopter, N508SQ, was substantially damaged when it impacted terrain while maneuvering south of Cheyenne, Wyoming. The commercial pilot, the sole occupant on board, was not injured. Reforestation Services, Inc., of Salem, Oregon, was operating the helicopter under Title 14 CFR Part 137. Visual meteorological conditions prevailed for this local aerial application flight, which originated approximately 15 minutes prior to the accident. The pilot had not filed a flight plan. According to the pilot, he was spraying vegetation along the Union Pacific railroad tracks. He was reversing course for a second application pass and began a "cyclic climb/ag turn" when he encountered a gust of wind, "approximately 15-20 miles per hour," from his "6 o'clock position." The pilot stated he was unable to recover before he hit the ground. Subsequently, the helicopter rolled on its right side, and the main rotor blades separated. An examination of the helicopter's systems revealed no anomalies. At 0911the Aviation Routine Weather Report (METAR) from Cheyenne reported winds from 320 degrees at 12 knots with gusts to 17 knots. ## Aircraft - Registration: [N508SQ](https://openairdocs.org/deregistered/N508SQ-2020-10-17), registration cancelled 2020-10-17, S/N 5086, built 1979 (OpenAirDocs) - Reported make and model: Hiller UH-12E - Registry model: [Hiller UH-12E](https://openairdocs.org/model/hiller-uh-12e) (registry code 4360122) (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: 5086 - Engines: Rolls-Royce 250-C20 420 horsepower turbo shaft - Damage: Substantial damage - Flight: Aerial application, Part 137 - Airworthiness certificate: Special, Restricted (Special) - Departed: NONE, Cheyenne, WY ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 39; injuries: none; commercial; instrument ratings: helicopter; medical: class 2, valid medical--no waivers/lim.; last flight review May 15, 2003; seat: left; flight hours: 11,500 total, 4,000 in this make and model, 11,300 as pilot in command, 10 in the last 90 days, 30 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 320° at 12 knots, gusting 17 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 79 °F, dew point 43 °F - Altimeter: 30.07 inHg - Observed at: CYS ## 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 20030530010949A](https://openairdocs.org/incident/20030530010949A), May 30, 2003: Hiller UH12E, Cheyenne, WY, Substantial damage. (-23) Pilot was spraying railroad right-of-way and then made a cyclic climb with a pedal turn. This pedal turn placed the helicopter in a down wind condition… 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.