ENG09IA004 · McDonnell-Douglas DC-10-30
Arrow Cargo McDonnell-Douglas DC-10-30 · Incident: uncontained engine failure during initial climb
Event
- NTSB case
- ENG09IA004
- 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
- 0
- 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
- Unknown
- WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
- Not recorded
McDonnell-Douglas DC-10-30
- Aircraft type
- McDonnell Douglas DC-10
- 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
- N526MD
- Operator
- Arrow Cargo
- Onboard fatalities
- Unknown
- Route
- From not recordedTo not recorded
- 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
- Unknown
- 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
- Initial climb
- 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
- Uncontained engine 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
Not plotted · Location withheld: coordinates are missing, conflicting, invalid, or have no accepted acquisition method. No substitute location has been invented.
NTSB narrative
The airplane experienced an uncontained No. 2 engine failure during climb out after takeoff, and an uneventful landing was accomplished. A post-incident airplane inspection found that the No. 2 engine low pressure turbine (LPT) case had separated circumferentially in plane with the LPT stage 3 (S3) turbine and that all components aft of the separation were liberated. The engine's LPT S3 disk front spacer arm was fractured circumferentially at the spacer to disk rim fillet. Metallurgical examination of the fracture surfaces revealed high cycle, high-amplitude fatigue (HAF) cracks initiating from sites around 90 percent of the forward spacer arm inner diameter. Inspection of the high pressure turbine (HPT) found that one stage 1 (S1) blade was missing approximately 85 percent of its airfoil material. The investigation found that the HPT blade damage resulted in synchronous vibration forces that 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 that exceeded the material endurance limit and caused high cycle/high amplitude fatigue cracks to initiate 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.
Probable cause
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.
Verbatim NTSB analysis and probable cause from the NTSB dataset
Sources
NTSB record ENG09IA004
- Event ID
- 20090326X91955
- Case number
- ENG09IA004
- 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. 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: 37ae20ea5dd7006b1ff3cfd517eefbd3670fbedb1a3a961c401ce4dea074fbfb; retrieved 2026-09-15T10:52:48.130Z.