# NTSB DCA25LA173: Boeing 787, N27958, Claveria, Philippines, March 27, 2025 - Type: NTSB accident investigation - Classification: Accident · Serious injuries · Class 4 · Limited · Final report - Date: March 27, 2025, 20:34 local (20:34 UTC) - Place: Claveria, Philippines · per notification, also described as 60nm east of Butuan City at FL 400 - Coordinates: 8.67491, 125.01017 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=8.6749&lon=125.0102&mi=10 - Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping) - Defining event: [Enroute-cruise: Turbulence encounter](https://openairdocs.org/ntsb-events/360) - Highest injury: Serious injuries - Injuries: 2 serious, 4 minor, 183 uninjured - Status: Completed, report October 23, 2025 - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Major Investigations Division - Parties: FAA/AVP110 - NTSB case key (mKey): 199959 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=DCA25LA173 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/199959/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=199959 - Page: https://openairdocs.org/ntsb/DCA25LA173 ## Probable cause An encounter with convective turbulence during cruise that was not detected in advance by cockpit weather radar or weather information services. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Turbulence: convective turbulence](https://openairdocs.org/ntsb-findings/03032020): Environmental issues › Conditions/weather/phenomena · Effect on personnel (probable cause); cases with it: [Boeing 787-9, 3 cases](https://openairdocs.org/ntsb-findings/03032020/cases.md?model=1385609), [All aircraft, 145 cases](https://openairdocs.org/ntsb-findings/03032020/cases.md) - [Knowledge: knowledge of meteorologic cond](https://openairdocs.org/ntsb-findings/02032020): Personnel issues › Experience/knowledge · Cabin crew; cases with it: [Boeing 787-9, 2 cases](https://openairdocs.org/ntsb-findings/02032020/cases.md?model=1385609), [All aircraft, 30 cases](https://openairdocs.org/ntsb-findings/02032020/cases.md) - [Knowledge: knowledge of meteorologic cond](https://openairdocs.org/ntsb-findings/02032020): Personnel issues › Experience/knowledge · Flight crew; cases with it: [Boeing 787-9, 2 cases](https://openairdocs.org/ntsb-findings/02032020/cases.md?model=1385609), [All aircraft, 30 cases](https://openairdocs.org/ntsb-findings/02032020/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Enroute-cruise: Turbulence encounter](https://openairdocs.org/ntsb-events/360) (defining event); cases with it: [Boeing 787-9, 5 cases](https://openairdocs.org/ntsb-events/360/sequence.md?model=1385609), [All aircraft, 423 cases](https://openairdocs.org/ntsb-events/360/sequence.md) ## Analysis United Airlines flight 1 encountered severe convective turbulence during cruise over the Republic of the Philippines, while enroute from San Francisco International Airport (KSFO), San Francisco, California, to Singapore Changi Airport (WSSS), Republic of Singapore. As a result of the turbulence, two flight attendants (FAs) sustained serious injuries, three FAs and one passenger sustained minor injuries. The airplane was not damaged, and the flight continued to its destination without further incident. The Civil Aviation Authority of the Philippines - Accident Investigation and Inquiry Board, delegated the investigation to the NTSB as the State of Operator and State of Registry. 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. Figure 1. The most intense scattered convective activity noted north/northeast of accident site (data fusion satellite imagery provided by United Airlines). 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. ## Aircraft - Registration: [N27958](https://openairdocs.org/aircraft/N27958), registered now, S/N 36406, built 2015 (OpenAirDocs) - Reported make and model: BOEING 787 (9) - Registry model: [Boeing 787-9](https://openairdocs.org/model/boeing-787-9) (registry code 1385609) (OpenAirDocs) - Registry engine: [GE GENX-1B74/75/ series](https://openairdocs.org/engine/ge-genx-1b74-75-series) (registry code 30222, turbo-fan) (OpenAirDocs) - Category: Airplane - Serial number: 36406 - Year built: 2015 - Airframe hours: 44260 - Engines: GE GENX-1B74/75/ 76700 lbs thrust turbo fan; GE GENX-1B74/75/ 76700 lbs thrust turbo fan - Damage: No damage - Flight: Part 121 - Operator: United Airlines Inc - Registered owner: United Airlines Inc - Airworthiness certificate: Standard, Transport - Last inspection: Continuous airworthiness, March 21, 2025 - Departed: SFO, San Franciso, CA - Destination: WSSS, Singapore, OF - Flight plan: IFR - Equipment: Data recorder, Auto-pilot, ADS-B, Stall warning system, Satellite tracking device, Onboard weather, Heads up display, Electronic primary flight display, Electronic multifunction display, Electronic flight bag or handheld device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 60; injuries: none; flight instructor, airline transport, flight engineer; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review June 4, 2024; seat: left; restraint: lap only; flight hours: 26,000 total, 2,480 in this make and model, 23,930 as pilot in command, 98 in the last 90 days, 80 in the last 30 days, 0 in the last 24 hours - Co-pilot; age 58; injuries: none; airline transport, flight instructor, flight engineer; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review February 7, 2025; seat: rear; restraint: lap only; flight hours: 19,100 total, 2,391 in this make and model, 4,170 as pilot in command, 112 in the last 90 days, 32 in the last 30 days, 13 in the last 24 hours - Other flight crew; injuries: none; flight instructor, flight engineer, airline transport; restraint: lap only; flight hours: 17,613 total - Other flight crew; injuries: none; airline transport; restraint: none; flight hours: 12,200 total ## Weather - Conditions: Instrument (IMC), Night/dark - Visibility: 10 statute miles - Temperature: 82 °F, dew point 75 °F - Turbulence: Severe - Observed at: RPLL, 434 nm away - METAR: METAR RPLL 272000Z VRB02KT 9999 FEW025 28/24 Q1007 NOSIG RMK A2974= ## Other investigations on N27958 (1) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB DCA16CA021](https://openairdocs.org/ntsb/DCA16CA021), Nov 7, 2015: Boeing 787 (N27958), Beaumont, TX, no damage. Probable cause: An inadvertent encounter with convective turbulence resulting in serious injury to a flight attendant. ## Docket (5 files) The files NTSB released with the investigation on October 23, 2025, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=199959. 5.2 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 10 pages, 3.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19408495&FileExtension=pdf&FileName=01-01-6120_1_Form%20UA1_print_Redacted-Rel.pdf - Crew statements (item 2, PDF, 12 pages, 228 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19408239&FileExtension=pdf&FileName=01-02%20Crew%20Statements-Rel.pdf - Weather reports and records (item 3, PDF, 23 pages, 750 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19408006&FileExtension=pdf&FileName=04-01%20Weather%20Records%20and%20Information%20Provided%20by%20UAL-Rel.pdf - Selected graphical flight data recorder information (item 4, PDF, 2 pages, 369 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19407822&FileExtension=pdf&FileName=08-01%20Graphical%20FDR%20Data%20Provided%20by%20UAL-Rel.pdf - Selected tabular flight data recorder information (item 5, XLSX, 216 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19408719&FileExtension=xlsx&FileName=08-02%20Tabular%20FDR%20Data%20Provided%20by%20UAL-Rel.xlsx From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.