Airbus Helicopters AS350B3e accident near Skwentna, Alaska, August 20, 2025
On August 20, 2025 at about 10:30 pm local time, a 2013 Airbus Helicopters AS350B3e, registered N589SH, was substantially damaged in an accident during standing (engine(s) operating) near Skwentna, Alaska. It was an external-load flight under external-load helicopter rules (Part 133). No one was hurt; 1 person was on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The pilot’s inadvertent entanglement of a lightweight Kevlar long line into the helicopters operating main rotor system, resulting in a severe imbalance and separation of the main rotor gearbox.
Source: NTSB aviation accident database, copy made October 4, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- August 20, 2025 · about 10:30 pm local time
- Place
- Skwentna, Alaska · map
- Type
- Accident
- Injuries
- No one was hurt; 1 person was on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Airbus Helicopters AS350B3e, built 2013 · all AS350B3es on the register
- Registration
- N589SH · registry record · serial 7745
- Damage
- Substantial damage
- Flight
- External-load flight · external-load helicopter rules (Part 133)
The NTSB's narrative final · quoted from the NTSB record
The operator reported that the helicopter was being used to sling construction equipment to a remote mine site located in an area of steep mountainous terrain. After the pilot placed the external load at a prearranged site next to the drill pad, he maneuvered the helicopter to a landing site in an area of rock-covered terrain to disconnect and stow the lightweight Kevlar long line that was still attached to the helicopter’s cargo hook. After a successful landing, the pilot reduced the engine throttle to ground idle, locked the flight controls, then exited the helicopter with the engine and rotor still operating. As the pilot coiled the Kevlar long line into the helicopter, a portion of the line became entangled in the rock covered terrain, and the pilot pulled hard to free it. As the Kevlar long line suddenly released from the rocks, the recoiling line became entangled in the operating main rotor blades which resulted in a severe main rotor imbalance. As a result, the main rotor gearbox and entire main rotor system were subsequently ripped from the helicopter. The helicopter sustained substantial damage to the fuselage, tail boom assembly, and main rotor drive system. The pilot reported that there were no preaccident mechanical failures or malfunctions with the helicopter that would have precluded normal operation.
The complete narrative as the NTSB published it. The NTSB's docket holds the report as a PDF and any photographs, statements and other documents from the investigation.
The factual record from the NTSB's investigation tables, in plain English
What happened, in order
- Miscellaneous/other during standing (engine(s) operating) defining event
The NTSB's findings
- Personnel issues › Action/decision › Action › Incorrect action performance › Pilot
- Environmental issues › Physical environment › Terrain › Rough terrain › Effect on operation
Pilot
- Certificate: commercial pilot
- Ratings: rotorcraft: helicopter
- Flight time: 15,500 hours in all; 9,900 in this make and model; 290 in the last 90 days; 50 in the last 30 days; 15,400 as pilot in command
- Last flight review: March 25, 2025
- Medical certificate: Class 2 (with waivers/limitations)
- Seat: none
- Injury: no injuries
The aircraft
- Airframe total time: 5,664.5 hours
- Last inspection: 100-hour inspection, August 9, 2025; 5 hours since
- Maximum gross weight: 4,961 lb
- Seats: 6
- Landing gear: fixed
- Engine: Safran ARRIEL 2D (turboshaft); 331 hours total
- Operator: Soloy Helicopters LLC
Weather at the time
- Light: daylight
- Visibility: 25 statute miles
- Sky: a few clouds at 2,700 ft
- Temperature: 55°F (13°C), dew point 52°F (11°C)
- Altimeter: 30.12 inHg
- Observation at 10:57 am from APT, 21 miles away
Weather report (METAR): PAPT 201857Z COR 00000KT 25SM FEW027 13/11 A3012 RMK NO SPECI
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Flight crew | 1 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
2 documents, released by the NTSB on October 23, 2025. View them here, or download them; the NTSB redacts some personal details before release, and this site shows the NTSB's own titles rather than its file names.
| # | Document | What it is | |
|---|---|---|---|
| 1 | Pilot/operator Aircraft Accident Report, NTSB Form 6120.1 | PDF, 10 pages | View Download |
| 2 | Photos | PDF, 3 pages | View Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
About this page
Everything above comes from the NTSB's public accident database: the narrative, probable cause and findings are the NTSB's own words, and the coded tables behind its report (pilot, aircraft, flight, weather, injuries, sequence of events) are written out in plain English. Pilots' ages, home towns and medical details are left out on purpose. The documents and photographs are the NTSB's docket, the folder of records gathered during the investigation, shown as the NTSB released them (the NTSB redacts some personal details first) and listed under the NTSB's own titles. This site's own text never names pilots, passengers or anyone else involved. A preliminary report describes what is known soon after the event and can change; the final report, with the probable cause, usually follows one to two years later and this page is refreshed when it does. Case number ANC25LA097.