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| Date: | Thursday 27 March 2025 |
| Time: | 20:34 UTC |
| Type: |  Boeing 787-9 Dreamliner |
| Owner/operator: | United Airlines |
| Registration: | N27958 |
| MSN: | 36406/342 |
| Year of manufacture: | 2015 |
| Total airframe hrs: | 44260 hours |
| Fatalities: | Fatalities: 0 / Occupants: 189 |
| Other fatalities: | 0 |
| Aircraft damage: | None |
| Category: | Accident |
| Location: | NE of Claveria -
 Philippines
|
| Phase: | En route |
| Nature: | Passenger - Scheduled |
| Departure airport: | San Francisco International Airport, CA (SFO/KSFO) |
| Singapore-Changi International Airport (SIN/WSSS) | |
| Investigating agency: | NTSB |
| Confidence Rating: |  Accident investigation report completed and information captured |
United Airlines flight UA1, a Boeing 787-9 Dreamliner, was en route at FL400 near Claveria, Philippines, when it encountered turbulence.
Two cabin crew members sustained serious injuries while three crew members and one passenger sustained minor injuries.
A review of weather records revealed areas of scattered convection were present to the northeast of the accident location. The flight crew reported that prior to the accident the flight was smooth, and they had been deviating around small, scattered returns noted on the cockpit weather radar as they flew southwest toward the intended destination.
The weather provider noted that there were no significant meteorological information (SIGMETs) or flight plan guidance advisories for turbulence or convective activity for the area, due to the scattered nature of the convection. Fusion satellite and lightning data showed isolated convective cells near the accident location and time, with lightning development and likely updrafts.
The flight crew reported that prior to the accident, the airplane was at flight level 400 in a thin cirrus cloud layer, there was no moonlight and the flight was smooth. The seatbelt sign was off.
Immediately before the turbulence encounter, cockpit weather radar displayed no returns ahead of the airplane at any range. There were no messages or alerts about weather from dispatch, nor any indication of weather activity from their 3rd party data sources (Skypath and WSI). The flight crew described the turbulence as a sudden and severe jolt that lasted 3-5 seconds, during which it was difficult to read the instrument panel. Immediately after the turbulence subsided, the flight was smooth.
The FAs working in the aft galley (where the serious injuries occurred) described the turbulence as sudden and brief, the airplane dropped beneath them (or they were lifted off their feet) and they fell to the floor with severe force.
The other cabin crew solicited assistance from passengers with medical experience and rendered aid to those injured. They enlisted a non-revenue FA to replace one of the injured crew, to cover one of the doors during landing.
The captain coordinated with the cabin crew, dispatch and the remote medical advisory service, and the first officer. After considering a diversion to Manila, they chose to continue to WSSS, which was about 80 minutes away. The flight crew declared an emergency, landed uneventfully, and medical personnel met the airplane at the gate. One FA sustained a broken ankle requiring surgery and another was hospitalized for longer than 48 hours with a head
injury.
Probable Cause and Findings
An encounter with convective turbulence during cruise that was not detected in advance by cockpit weather radar or weather information services.
Accident investigation:
 |
|
Sources:
NTSB
https://www.flightaware.com/live/flight/N27958/history/20250327/0550Z/KSFO/WSSS
History of this aircraft
Other occurrences involving this aircraft
| 7 November 2015 | N27958 | United Airlines | 0 | Beaumont, Texas |  |
non |
| Turbulence | ||||||
| 4 July 2016 | N27958 | United Airlines | 0 | 26nm northeast of Sydney |  |
min |
| Bird strike | ||||||
| 3 July 2020 | N27958 | United Airlines | 0 | near Tokyo/Narita International Airport (NRT/RJAA) |  |
min |
| 26 September 2024 | N27958 | United Airlines | 0 | 140 nm ESE of Churchill, MB |  |
non |
Location
Revision history:
| Date/time | Contributor | Updates |
|---|---|---|
| 15-Apr-2025 17:10 | ASN | Added |
| 15-Apr-2025 17:12 | ASN | Updated [Source, ] |
| 01-Nov-2025 13:51 | ASN | Updated [Time, Narrative, Category, Accident report, ] |
Corrections or additions? ... Edit this accident description
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