Boeing B747 incident near Jeddah, SA, July 5, 2008
On July 5, 2008, a Boeing B747, registered HSVAC, suffered minor damage in an incident during initial climb near Jeddah. It was flown under foreign airline rules (Part 129). The NTSB record does not give the injuries.
The NTSB's probable cause their words, unchanged
Failure of the low pressure turbine stage 3 disk due to a design that is vulnerable to high pressure turbine unbalance-induced synchronous vibration that cannot be detected in flight, and the subsequent uncontained engine failure.
Source: NTSB aviation accident database, copy made October 5, 2026. Docket and reports at the NTSB.
What the record shows
- Date
- July 5, 2008
- Place
- Jeddah, Saudi Arabia
- Type
- Incident
- Injuries
- The NTSB record does not give the injuries.
- Weather
- not recorded
- Aircraft
- Boeing B747 306
- Registration
- HSVAC · no longer on the register
- Damage
- Minor damage
- Flight
- Flight · foreign airline rules (Part 129)
The NTSB's narrative final · quoted from the NTSB record
The airplane made an air turnback and successful landing following an uncontained No. 1 engine failure during initial climb after takeoff. There was minor impact damage to the airplane's left wing and flaps. The No. 1 engine low pressure turbine (LPT) case had separated circumferentially in plane with the stage 3 (S3) LPT turbine, and the engine components aft of the separation were liberated. A high pressure turbine (HPT) borescope inspection found localized airfoil damage sufficient to result in HPT rotor unbalance. HPT rotor unbalance-induced synchronous vibration forces interacted with the engine LPT rotor system through a common bearing support and excited a bladed-disk mode response in the LPT S3 disk. The resonant amplitude of the alternating stress experienced by the disk resulted in bending loads exceeding the material endurance limit, and high cycle/high amplitude fatigue cracks initiated along the LPT S3 disk forward spacer arm rim diameter. Once initiated, the cracks propagated rapidly through the spacer arm thickness and the individual cracks joined to form a single circumferential crack, resulting in the separation of the disk at the forward spacer arm. The freed aft portion of the LPT rotor accelerated and penetrated the engine case, releasing high-energy debris as disk fragments and all of the engine components aft of the LPT S3 nozzles were liberated. NTSB Safety Recommendations A-10-98 and A-10-99 (Urgent); A-10-100, and A-10-101 were published in connection with this investigation. For further information about these recommendations, see NTSB case number ENG09IA004.
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
- Engine shutdown during initial climb
- Loss of engine power (partial) during initial climb
- Part(s) separation from AC during initial climb
- Uncontained engine failure during initial climb defining event
The NTSB's findings
- cause Aircraft › Aircraft power plant › Engine (turbine/turboprop) › Turbine section › Design
The aircraft
- Landing gear: fixed
- Engine: General Electric CF5-50 (turbofan); 0 hours total
- Operator: Saudi Arabian Airlines
The flight
- Departed from: Jeddah
- Destination: Jakarta
- Flight plan: not recorded
Weather at the time
- Temperature: 0°F (-18°C), dew point 0°F (-18°C)
Documents from the investigation the NTSB's docket: the evidence folder behind the report
The docket, the folder of records gathered during an investigation (maintenance records, photographs, witness statements, examinations), has not been read from the NTSB for this case yet; the list appears here once it has. Open the docket at the NTSB.
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.