Boeing 787 incident near Singapore, Outside the U.S., May 14, 2024
On May 14, 2024 at about 2:00 pm local time, a Boeing 787, registered N27957, suffered minor damage in an incident during initial climb near Singapore, Outside the U.S.. It was flown under scheduled airline rules (Part 121). No one was hurt; 210 people were on board or involved. The weather was visual conditions (good weather).
The NTSB's probable cause their words, unchanged
The uncontained left engine failure was caused by the failure and liberation of the HPT stage 1 aft blade retainer as a result of a fatigue crack in the upper collet radius that originated from a surface connected cluster of Oxide/Carbonitride/Nitride/Carbide (OCNC) particles. Contributing to the failure of the HPT stage 1 aft blade retainer was an unknown material behavior unique to OCNC clusters in Rene 65 material that are surface connected in highly stressed material that may result in a localized reduction of material fatigue life capability.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- May 14, 2024 · about 2:00 pm local time
- Place
- Singapore, Singapore · map
- Type
- Incident
- Injuries
- No one was hurt; 210 people were on board or involved.
- Weather
- visual conditions (good weather)
- Aircraft
- Boeing 787 9 · all 787s on the register
- Registration
- N27957 · registry record · serial 36409
- Damage
- Minor damage
- Flight
- Flight · scheduled airline rules (Part 121)
The NTSB's narrative final · quoted from the NTSB record
The No. 1 (left) engine high pressure turbine (HPT) stage 1 aft blade retainer developed a fatigue crack that initiated and propagated through thickness and circumferentially until final overload failure that was not contained by the turbine case. Fractography of the HPT stage 1 aft blade retainer revealed the crack initiated in the upper collet radius at a single point of origin which corresponded to a surface connected material anomaly that measured 0.005 inches by 0.015 inches by 0.0005 inches. The fracture surface contained an area of intergranular fracture morphology with visible beach marks, consistent with hold-time fatigue growth and the remaining fracture surface was consistent with overload fracture. Further examination of the material anomaly was determined to be a cluster of particles enriched with Titanium, Aluminum, Zirconium, Magnesium, and Oxygen, which is consistent with Oxide/Carbonitride/Nitride/Carbide (OCNC) particles. Analysis of the HPT stage 1 aft blade retainer material found all dimensional and material characteristics to be conforming to GE Aerospace drawings and material specifications. The presence of OCNC particles and clusters of particles is inherent to Rene 65 material with quantity and size distributions accounted for within GE’s philosophy for material life limit calculations. The calculated stress conditions for the GEnx HPT stage 1 aft blade retainer collet feature were found to be uniquely high when compared to the stress conditions of other rotating hardware. This higher stress environment was determined to be the result of the assembly interference fits between the HPT stage 1 disk, the HPT stage 1 aft blade retainer, and the HPT mid seal in combination with the engine’s operational loads. Analysis of material test data suggests that surface connected OCNCs have a reduced crack incubation/nucleation life at high stress conditions, and that surface connected OCNCs do not behave according to traditional crack growth threshold behavior. Activation of surface connected OCNCs can in fact reduce material fatigue life capability but not every OCNC will initiate a crack, suggesting an unknown bimodal behavior.
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
- Uncontained engine failure during initial climb defining event
The NTSB's findings
- Aircraft › Aircraft power plant › Power plant › (general) › Failure
The aircraft
- Landing gear: retractable
- Engine 1: Ge Aerospace GEnx-1B76A/P2 (turbofan); 0 hours total
- Engine 2: Ge Aerospace GEnx-1B76A/P2 (turbofan); 0 hours total
- Operator: United Airlines
The flight
- Departed from: WSSS Singapore OF
- Destination: KSFO San Francisco CA
- Flight plan: IFR
- A second pilot was aboard
Weather at the time
- Light: night
- Sky: broken clouds at 30,000 ft; a few clouds
- Temperature: 81°F (27°C), dew point 79°F (26°C)
Injuries
| Fatal | Serious | Minor | None | |
|---|---|---|---|---|
| Cabi | 10 | |||
| Flight crew | 4 | |||
| Passengers | 196 |
Documents from the investigation the NTSB's docket: the evidence folder behind the report
4 documents, released by the NTSB on September 3, 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 | ENG24LA014 - Powerplant Factual Report Final JULY2025 | PDF, 77 pages | View Download |
| 2 | Attachment 1 - AVENG-558171A Genx Blade Retainer Ual 956-102- NTSB Final | PDF, 69 pages | View Download |
| 3 | Fdr-recorders REPORT_ENG24LA014_FINAL | PDF, 14 pages | View Download |
| 4 | Flight Data Recorder Factual Report - Attachment 1 | data file | Download |
The same docket at the NTSB · documents without a copy here are fetched from the NTSB when you open them.
Everything on this page comes from the NTSB's public records. The narrative, probable cause and findings are the NTSB's own words; the coded tables behind the report are written out in plain English, with pilots' ages, home towns and medical details left out. The documents and photographs are the NTSB's docket, shown as the NTSB released them. This site's own text never names anyone involved. A preliminary report can change; the final report usually follows one to two years later, and the page is refreshed when it does.