Delta Air Lines Flight 55
Boeing 777 232 · Incident: powerplant system/component malfunction/failure during takeoff
From Hartsfield Jackson Atlanta International Airport (KATL) to Narita International Airport (NRT)
Event
- NTSB case
- ENG09IA002
- Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
- Incident
- InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
- Completed
- API-reported fatalities
- 0 · all aircraft and ground
- Ground fatalities
- Unknown
- OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
- Airline
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Not recorded
Boeing 777 232
- Aircraft type
- Boeing 777
- Category
- Airplane
- RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
- N864DA
- Operator
- Delta Air Lines
- Onboard fatalities
- Unknown
- Route
- From Hartsfield Jackson Atlanta International Airport (KATL), Atlanta, GATo Narita International Airport (NRT), Tokyo Narita
- Aircraft age
- Not recorded
- Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
- Part 121: Air Carrier
- Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
- Takeoff · rejected takeoff
- Defining eventThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
- Powerplant system/component malfunction/failure
- DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
- Minor
Cause areas
- Aircraft › Aircraft power plant
Approximate · Coordinates from the NTSB case API, which marks them as estimated or does not say; no uncertainty radius is established.
NTSB narrative
The Boeing 777 airplane experienced a contained fan blade fracture in the No. 2, right, engine, a Rolls-Royce plc RB.211 Trent 895-17 turbofan, during the takeoff roll at the Hartsfield Jackson Atlanta International Aiport. The examination of the fan blade revealed it had fractured from a fatigue crack that had initiated at the intersection of the convex side aft corner of the shear key slot and bedding flank. The examination of the fan blade also revealed the plasma spray coating was deteriorated and the dry film lubricant was almost completely gone. A survey by the engine manufacturer of the operator's 777 engine usage indicated that because of the loads and lengths of the flights, the operator was operating their Trent 895-17 engines at higher thrust levels with correspondingly high fan rotational speeds, which were still within the engine's operating limits, than any other operator. The survey also indicated the operator was operating its 777 and Trent engines significantly more hours per cycle than any other Trent 895 operator. An analysis by the engine manufacturer indicated that the blade fracture was caused by a combination of the breakdown of the lubrication system and residual fatigue life usage in the blade root following the last overhaul coupled with the high operating stresses in the fan blade from the high thrust settings.
Probable cause
The fan blade fractured due to a fatigue crack that was the result of the combination of the breakdown of the fan blade lubrication system and residual fatigue life usage following the last overhaul of the fan blade. Contributing to the fracture was the inadequate lubrication schedule established by the engine manufacturer that was not reflective of the operator’s use of the engine.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ENG09IA002
- Event ID
- 20090105X01036
- Case number
- ENG09IA002
- Dataset
- full-current
- Source SHA-256
- 5cf380f0061817c0331a6b2d8cc7e0ee3a79bea469a1001dc5c10e56f35f5ab3
Source notes (4)
- Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
- Filled from the NTSB case API where the bulk record had no value: investigation status, coordinates. Values present in the bulk record are kept.
- The date is the local date, which is the same as the UTC date the NTSB stores.
- API snapshot SHA-256: ea41700fc678b1fd6c288de1de72f5f6d9f4401663dcb6698f49a22f26cff822; retrieved 2026-09-15T10:39:51.023Z.