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WPR19LA194 · Bell 47G 3B 1

13 Jul 2019 · Mosby, MT, United States

Bell 47G 3B 1 · Accident: loss of control in flight during landing

From Benzien, MT to Mosby, MT

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Event

NTSB case
WPR19LA194
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
General aviation
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 47G 3B 1

Aircraft type
Bell 47
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
N3078G
Operator
Unknown
Onboard fatalities
Unknown
Route
From Benzien, MTTo Mosby, MT
Aircraft age
About 55 years (built 1964)
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
Part 91: General Aviation
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 control in flight
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

  • Personnel issues › Task performance

Approximate · Coordinates as recorded by the NTSB; no uncertainty radius is established.

NTSB narrative

The pilot had refueled the helicopter, bringing the total fuel on board to about 58 gallons, and departed with two passengers for a 15-mile flight to a private ranch. After arriving at the destination, the pilot circled the area and determined the wind direction. He established a normal approach path into the wind to land near a building. While about 30 to 40 feet above ground level, the helicopter entered an uncommanded yaw to the right. Despite the pilot’s control inputs, which included application of full left pedal, the helicopter continued to yaw to the right. The pilot attempted to recover and applied forward cyclic to gain airspeed to go-around. The helicopter continued to yaw right and ascended above the building as described by the two passengers and a witness located near the building. During the recovery attempt, the pilot recalled initially lowering the collective when the yaw first occurred, but did not recall raising or lowering it again. The pilot lost control of the helicopter, which subsequently impacted the ground in a silage pit about 250 feet north of the intended landing area.

An engine test run and airframe examination revealed no mechanical failures or malfunctions with the helicopter that would have precluded normal operation. During the approach, the helicopter was operating in a high-power demand condition due to high density altitude, high gross weight, and while near the out-of-ground effect boundary and at a slow airspeed. These conditions reduced the amount of yaw control effectiveness available to counter an uncommanded right yaw. Additionally, the pilot’s selected approach path placed the helicopter on the leeward side of a building and likely exposed the helicopter to disturbed air that disrupted the airflow entering the main rotor and tail rotor and initiated the uncommanded right yaw/loss of tail rotor effectiveness. During the recovery attempt, the pilot likely increased the collective while applying full left pedal, which resulted in the ascent described by the passengers and witness. The added power from the increased collective would also have resulted in an increased right yaw rate and the subsequent loss of control.

Probable cause

The pilot’s failure to account for environmental conditions conducive to a loss of tail rotor effectiveness, which resulted in a loss of tail rotor effectiveness and subsequent loss of control. Contributing to the accident was the pilot’s inappropriate application of power during the recovery.

Verbatim NTSB analysis and probable cause from the NTSB dataset

Sources

NTSB record WPR19LA194
Event ID
20190714X00745
Case number
WPR19LA194
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: 4f54f5e2320c4653aad298c902e84e9c9df0b7379bbf11e6b8e7da7a774effb4; retrieved 2026-09-16T09:24:44.510Z.