# NTSB Incident ENG12IA003
> **BOEING 747-451** · 2011-10-23 · Detroit, MI, USA · NONE
## Event
- **NTSB number:** ENG12IA003
- **Event ID:** 20111024X74546
- **Type:** Incident
- **Date:** 2011-10-23
- **Location:** Detroit, MI, USA
- **Coordinates:** 42.349647, -83.059921
## Injuries
- **Highest injury:** NONE
- **Fatal:** 0
- **Serious:** 0
- **Minor:** 0
- **Uninjured:** 394
- **Total aboard:** 394
## Aircraft
- **Make:** BOEING
- **Model:** 747-451
- **Registration:** N661US
- **FAR Part:** 121
- **Engines:** 4
- **Damage:** MINR
## Conditions
- **Light:** —
- **Weather:** —
## Probable cause

The penetration of turbine blade fragments through the rear turbine case, which punctured the No. 4 bearing oil pressure supply tube, allowing misted oil to contact the hot engine case and ignite the undercowl fire.  Contributing to the incident was the installation of approved (but not preferred) stage 3 low pressure turbine outer transition duct segments with the riveted rear seal configuration and the failure of the engine design to comply with the engine debris containment requirements of 14 Code of Federal Regulations 33.13 and 33.75.

---
*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=ENG12IA003) · AI Analytics · CC0 1.0*