# NTSB DEN99LA002: Bell 206B, N992SM, Vernal, UT, October 3, 1998 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: October 3, 1998, 17:30 local (23:30 UTC) - Place: Vernal, UT - Coordinates: 40.550643, -109.569869 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=40.5506&lon=-109.5699&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report May 19, 1999 - Report: Approved by Office Director - NTSB case key (mKey): 44153 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DEN99LA002 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/44153/pdf - Page: https://openairdocs.org/ntsb/DEN99LA002 ## Probable cause Loss of tail rotor effectiveness. A factor was the quartering tailwind. ## Sequence of events In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf). - Loss of control - in flight, landing - hovering turn - attempted, pilot in command - weather condition - tailwind (contributing factor) - weather condition - crosswind (contributing factor) - loss of tail rotor effectiveness - encountered, pilot in command (cause) - rotation - uncontrolled - In flight collision with terrain/water, hover - terrain condition - ground (contributing factor) ## Analysis THIS CASE WAS MODIFIED DECEMBER 20, 2005. The pilot was attempting to land in a strong quartering tailwind because his passenger had become air sick. He said the helicopter 'was practically in a hover [with] full power applied. . .when a gust of wind from behind hit me just as I was turning into the wind using left pedal. The helicopter weather vaned, I reacted with full right pedal and then the gust either stopped or came from a different direction weather vaning us back to the west where I applied full left pedal. I could feel buffeting in the controls similar to turbulence. The right yaw was so rapid that I entered loss of tail rotor effectiveness.' The helicopter collided with terrain while it was still turning and rolled over. According to the passenger, the pilot had attempted landings earlier in the day but had difficulty with the wind. He succeeded in landing after several attempts. ## Factual narrative THIS CASE WAS MODIFIED DECEMBER 20, 2005. On October 3, 1998, approximately 1730 mountain daylight time, a Bell 206B, N992SM, was substantially damaged when it collided with terrain during landing near Vernal, Utah. The private pilot and his passenger were not injured. Visual meteorological conditions prevailed, and no flight plan had been filed for the personal cross-country flight being conducted under Title 14 CFR Part 91. The flight originated at Steamboat Springs approximately 1700. According to the pilot's accident report, his passenger became air sick and he was attempting to land with a strong quartering tailwind. The pilot said the helicopter "was practically in a hover [with] full power applied...when a gust of wind from behind hit me just as I was turning into the wind using left pedal. The helicopter weather vaned, I reacted with full right pedal and then the gust either stopped or came from a different direction weather vaning us back to the west where I applied full left pedal. I could feel buffeting in the controls similar to turbulence. The right yaw was so rapid that I entered loss of tail rotor effectiveness." The helicopter collided with terrain while it was still turning and rolled over. According to the passenger's statement, the pilot had attempted to land at Kremmling, Colorado, earlier in the day but had difficulty with the wind. After several attempts, he landed. The passenger also stated he felt the difficulties with the landings at Kremmling, Colorado, and Vernal, Utah, was due to "low clouds, rain and poor visibility." Visual meteorological conditions prevailed at Unitah County Airport, Vernal, Utah, located 35 miles west of the accident site. The helicopter's left skid and main rotor blades were severed on impact. ## Aircraft - Registration: N992SM (not matched to a registry record) - Reported make and model: Bell 206B - Category: Helicopter - Serial number: 4181 - Airframe hours: 55 - Engines: Allison 250-C20J 317 horsepower turbo shaft - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Enterprise Aviation, Inc., doing business as Park City Helicopters - Registered owner: Charles Ward - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, September 18, 1998, 1,190 hours before - Departed: SBS, STEAMBOAT SPRGS, CO - Destination: BTF, SALT LAKE CITY, UT ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 27; commercial; instrument ratings: helicopter; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 560 total, 62 in this make and model, 50 as pilot in command, 85 in the last 90 days, 60 in the last 30 days, 3 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 350° at 10 knots - Visibility: 10 statute miles - Lowest ceiling: 6,000 ft broken - Temperature: 46 °F, dew point 43 °F - Altimeter: 29.00 inHg - Observed at: VEL, 35 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 19981003028029A](https://openairdocs.org/incident/19981003028029A), Oct 3, 1998: Bell 206B, Vernal, UT, Destroyed. (.19) On October 3, 1998, approximately 1730 mountain daylight time, a Bell 206B, N992SM, was destroyed when it collided with terrain during landing near… 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.