WPR16LA142 · Bell UH 1H
King County Sheriffs Office Bell UH 1H · Accident: loss of tail rotor effectiveness during landing
From Yakima Air Terminal McAllister Field (YKM) to Mt. Adams, WA
Event
- NTSB case
- WPR16LA142
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Accident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- Government
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Visual Meteorological Cond
Bell UH 1H
- Aircraft type
- Bell UH-1
- Category
- Helicopter
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N790RJ
- Operator
- King County Sheriffs Office
- Onboard fatalities
- Unknown
- Route
- From Yakima Air Terminal McAllister Field (YKM), Yakima, WATo Mt. Adams, WA
- Aircraft age
- About 46 years (built 1970)
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Public Aircraft
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Landing
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Loss of tail rotor effectiveness
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Substantial
Cause areas
- Aircraft › Aircraft oper/perf/capability
- Personnel issues › Task performance
Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.
NTSB narrative
The commercial pilot was conducting a public flight in the helicopter to transport two search and rescue personnel to a landing zone located in mountainous terrain at an elevation of about 7,800 ft. The pilot reported that he aborted his first approach, which was from the north, because he felt that he was using too much left pedal. On his second approach, which was from the south, the helicopter yawed right. The pilot recognized that a loss of tail rotor effectiveness was occurring. He attempted to recover control by reducing the collective and applying forward cyclic; however, the helicopter spun and impacted the ground.
The pilot reported that there were no mechanical malfunctions or failures with the helicopter that would have precluded normal operation. It is likely that, during the landing approach, as the helicopter's airspeed dropped below effective translational lift and the pilot added power to compensate, there was insufficient left pedal to stop the resulting right yaw, and the pilot lost control of the helicopter due to a loss of tail rotor effectiveness.
Probable cause
The pilot’s failure to maintain yaw control as he slowed the helicopter during a landing approach, which resulted in the loss of helicopter control due to the loss of tail rotor effectiveness.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record WPR16LA142
- Event ID
- 20160718X32942
- Case number
- WPR16LA142
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: 7feb4a199475eb5a9180ef236cf7e35278911a176f142118188ffe87f5c556cc; retrieved 2026-09-16T03:39:55.428Z.