- Date
- August 9, 1994, 12:30 local (20:30 UTC)
- Place
- Chuit River, AK
- Injuries
- 5 uninjured
- Damage
- Substantial damage
- Phase of flight
- Maneuvering
- Aircraft
- N4604YBell 206B
- Weather
- Visual (VMC) · Day
- Status
- Completed · report May 10, 1995
- Report
- Approved by Office Director
- NTSB office
- Alaska Regional Office
- FAA report
- 19940809020979A
- Case key
- 2539
From the NTSB’s public API. By law, NTSB reports can’t be used as evidence in lawsuits over the accident.
On this page
Probable cause
The pilot's failure to maintain tail rotor effectiveness during hover.
Sequence of events
NTSB’s coding before 2008: each occurrence and phase of flight, and the causes and factors under it. The codes are defined in NTSB’s coding manual.
Analysis
The pilot landed on a gravel bar in a River which had high banks. The wind was variable during the approach and landing. He 'picked' the helicopter back up to a hover to reposition on the gravel bar and the helicopter began to turn to the right. He applied left pedal, felt a response, but was unable to stop the turn. During the turn the helicopter descended and struck the water. After everyone exited the helicopter, it rolled over and sank in the River. According to the manufacturer and the FAA, when a helicopter is operating at or near its maximum gross weight, tail rotor control may become marginal depending on wind conditions. Hovering with a tailwind may cause temporary loss of tail rotor effectiveness and allow the helicopter to rotate about its vertical axis. The purpose of the flight was fish guiding.
Factual narrative
On August 9, 1994, at 1230 Alaska daylight time, a skid equipped Bell 206B helicopter, registered to and operated by the pilot, crashed into the Chuit River. The business flight, operating under 14 CFR Part 91 for the purpose of fish guiding, departed the Anchorage, Alaska area and the destination was the Chuit River, 1 mile upstream from the mouth. Visual meteorological conditions prevailed and no flight plan was filed. The pilot and the four passengers were not injured and the helicopter rolled over and sank in the river.
According to the pilot, the wind was variable during his approach and landing. The gravel bar on which he landed was not level so he picked the helicopter back up to a hover to move to a more level location. The helicopter immediately made a turn to the right. He applied left pedal and could feel a response but was unable to stop the rotation before the helicopter struck the water. The helicopter came to rest upright in the river. Everyone exited the helicopter and it rolled over and sank in the river.
According to Bell Helicopter and the FAA, when a helicopter is operating at or near its maximum gross weight, tail rotor control may become marginal depending on wind conditions. Hovering with a tailwind may cause temporary loss of tail rotor effectiveness and allow the helicopter to rotate about its vertical axis.
The pilot's flight time was provided by the FAA and came from his Application for Airman Certificate dated 9/24/92.
Aircraft
- Registration
- N4604Y
- Reported as
- Bell 206B
- Category
- Helicopter
- Serial number
- 556
- Engine
- Allison 250-C20, 318 horsepower, turbo shaft
- Damage
- Substantial damage
- Flight
- Business · Part 91
- Registered owner
- Oney, Anthony L
- Airworthiness certificate
- Standard, Normal
- Departed
- LHD · Anchorage, AK
Matched to the registry by N-number and the event date; the registry’s history has gaps, so older matches can be wrong. Compare the reported make and model.
Flight crew
As NTSB recorded them. NTSB leaves out names.
- Role
- Pilot
- Age
- 33
- Certificates
- Commercial, Airline transport
- Airplane ratings
- Single-engine sea, Multi-engine land, Single-engine land
- Instrument ratings
- Helicopter, Airplane
- Medical
- Class 1, Valid Medical--no waivers/lim.
- Seat
- Right
- Flight hours
- 6,500 total · 1 in the last 24 hours
Weather
- Conditions
- Visual (VMC) · Day
- Visibility
- 50 statute miles
- Temperature
- 61 °F
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.