# NTSB Accident CHI05MA011
> **Boeing 747-132** · 2004-10-21 · Lake Michigan, USA · NONE
## Event
- **NTSB number:** CHI05MA011
- **Event ID:** 20041028X01714
- **Type:** Accident
- **Date:** 2004-10-21
- **Location:** Lake Michigan, USA
- **Coordinates:** 42.075553, -86.867225
## Injuries
- **Highest injury:** NONE
- **Fatal:** 0
- **Serious:** 0
- **Minor:** 0
- **Uninjured:** 5
- **Total aboard:** 5
## Aircraft
- **Make:** Boeing
- **Model:** 747-132
- **Registration:** N709CK
- **FAR Part:** 121
- **Engines:** 4
- **Damage:** SUBS
## Conditions
- **Light:** NITE
- **Weather:** VMC
## Probable cause

The number one engine separated from the airplane during climb due to the uncontained separation of a portion of the second stage turbine disk rim after the second stage turbine vanes contacted the disk.  The second stage turbine vanes contacted the second stage turbine disk due to the operator's inadequate inspection of the high pressure turbine module and the improper repair of the module by unknown maintenance personnel.

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*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=CHI05MA011) · AI Analytics · CC0 1.0*