# NTSB SEA91TL#02: Hiller-Soloy UH-12E, N7173S, Vernal, UT, September 18, 1991

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Class 3 · Final report
- Date: September 18, 1991, 16:14 local (22:14 UTC)
- Place: Vernal, UT
- Location: 40.4517° N, 109.5381° W: Placed by OpenAirDocs: center of Vernal, UT, within about 6 miles (OpenAirDocs)
- Nearby events: https://openairdocs.org/map.md?lat=40.4517&lon=-109.5381&mi=10
- Highest injury: No injuries
- Status: Completed
- Investigation class: Class 3
- NTSB case key (mKey): 41556
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=SEA91TL#02
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/41556/pdf
- Page: https://openairdocs.org/ntsb/SEA91TL%2302

## Aircraft

- Registration: [N7173S](https://openairdocs.org/aircraft/N7173S), registered now, S/N 2351, built 1965 (OpenAirDocs)
- Reported make and model: HILLER-SOLOY 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
- Damage: Destroyed
- Fire: Unknown
- Flight: Public aircraft, Public use
- Operator: Conrad Evans (For Blm)
- Flight plan: Unknown

## Weather

- Conditions: Visual (VMC), Not reported
- Lowest ceiling: none
- Temperature: 70 °F, dew point 45 °F
- Altimeter: 30.00 inHg
- Observed at: VEL

## Other investigations on N7173S (1)

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.

- [NTSB CEN20LA073](https://openairdocs.org/ntsb/CEN20LA073), Feb 1, 2020: Hiller UH 12E (N7173S), Dinosaur, CO, substantial damage. Probable cause: Failure of a S4 compressor blade due to a fatigue crack that likely initiated at a corrosion pit. Contributing to the accident was maintenance personnel’s failure to detect the corrosion pits during…

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.

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