- Date
- May 9, 2023, 12:00 local (20:00 UTC)
- Place
- Skwentna, AK
- Injuries
- 2 minor, 1 uninjured
- Damage
- Substantial damage
- Phase of flight
- Maneuvering
- Aircraft
- N704TRobinson Helicopter R44 II
- Defining event
- Maneuvering: VFR encounter with IMC
- Weather
- Day
- Status
- Completed
- Report
- Approved by Office Director
- Investigation class
- Class 4 - Basic report with no Prelim publish
- NTSB office
- Alaska Regional Office
- Parties
- FAA
- FAA report
- 20230509002709A
- Case key
- 139291
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 NTSB’s determination of the probable cause, and any contributing factors.
The pilot's failure to maintain adequate altitude/clearance from terrain while maneuvering in adverse weather conditions, which resulted in a dynamic rollover.
Findings · 4
NTSB’s coded findings. Those marked are part of the probable cause; the rest are factors or other findings.
Analysis
The pilot reported that, he was flying uphill over an area of snow-covered, mountainous terrain, when he encountered flat light and whiteout conditions, which made it difficult to discern topographical features. In an attempt to maintain visual reference with the ground, he turned the helicopter to the right to fly back down the hill. Subsequently, the right landing gear skid contacted terrain and the helicopter entered a dynamic rollover to the right, resulting in substantial damage to the fuselage, tail boom, and powertrain system. The pilot reported that there were no preaccident mechanical malfunctions or anomalies that would have precluded normal operation.
Sequence of events
The events NTSB coded, in order, by phase of flight. The defining event is the one that best describes the accident.
Aircraft
- Registration
- N704T
- Reported as
- Robinson Helicopter R44 II
- Category
- Helicopter
- Serial number
- 10343
- Built
- 2004
- Airframe hours
- 3,191.4
- Engine
- Lycoming IO-540-AE1A5, 260 horsepower, reciprocating
- Damage
- Substantial damage
- Flight
- Business · Part 135
- Operator
- Willow Creek Aviation, doing business as Remote Alaska Air
- Registered owner
- C & J Leasing LLC
- Airworthiness certificate
- Standard, Normal
- Last inspection
- Annual · December 22, 2022
- Departed
- SKW · Skwentna, AK
- Destination
- Skwentna, AK
- Flight plan
- Company VFR
- Equipment
- Handheld GPS
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
- 45
- Injuries
- Minor
- Certificate
- Commercial
- Airplane ratings
- Single-engine sea, Single-engine land, Multi-engine land
- Instrument ratings
- Airplane
- Medical
- Class 2, With waivers/limitations
- Last flight review
- April 19, 2023
- Seat
- Front
- Restraint
- 3-point
- Flight hours
- 10,570 total · 398 in this make and model
Weather
- Conditions
- Day
- Wind
- 130° at 9 knots, gusting 18
- Visibility
- 10 statute miles
- Lowest ceiling
- None
- Temperature
- 48 °F, dew point 28 °F
- Altimeter
- 29.82 inHg
- Observed at
- PAWS, 64 nm away
- METAR
- PAWS 091956Z AUTO 13009G18KT 10SM CLR 09/M02 A2982 RMK AO2 SLP104 T00941022
Docket · 2
The files NTSB released with the investigation on July 7, 2023, on NTSB’s docket system: statements, records, photos and specialists’ reports. 6.3 MB in all.
FAA reports on this event · 1
The FAA’s own accident and incident reports, matched to the aircraft by N-number and date.