# NTSB Incident CHI95IA028
> **BOEING 747-251B** · 1994-11-02 · CHICAG0, IL, USA · NONE
## Event
- **NTSB number:** CHI95IA028
- **Event ID:** 20001206X02567
- **Type:** Incident
- **Date:** 1994-11-02
- **Location:** CHICAG0, IL, USA
## Injuries
- **Highest injury:** NONE
- **Fatal:** 0
- **Serious:** 0
- **Minor:** 0
- **Uninjured:** 3
- **Total aboard:** 3
## Aircraft
- **Make:** BOEING
- **Model:** 747-251B
- **Registration:** N631US
- **FAR Part:** 091
- **Engines:** 4
- **Damage:** MINR
## Conditions
- **Light:** NR
- **Weather:** VMC
## Probable cause

inattentive maintenance service of the airplane by the mechanic who failed to disengage the constant speed drive (CSD) after the engine runup had been completed.  A factor in this incident was the lead mechanic not performing maintenance record keeping after being informed that the CSD had been recoupled.

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*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=CHI95IA028) · AI Analytics · CC0 1.0*