# NTSB Incident CHI89IA083
> **MCDONNELL DOUGLAS DC-9-82** · 1989-05-02 · MINNEAPOLIS, MN, USA · NONE
## Event
- **NTSB number:** CHI89IA083
- **Event ID:** 20001213X28263
- **Type:** Incident
- **Date:** 1989-05-02
- **Location:** MINNEAPOLIS, MN, USA
## Injuries
- **Highest injury:** NONE
- **Fatal:** 0
- **Serious:** 0
- **Minor:** 0
- **Uninjured:** 96
- **Total aboard:** 96
## Aircraft
- **Make:** MCDONNELL DOUGLAS
- **Model:** DC-9-82
- **Registration:** N434AA
- **FAR Part:** 121
- **Engines:** 2
- **Damage:** MINR
## Conditions
- **Light:** DAYL
- **Weather:** VMC
## Probable cause

FAILURE OF THE HYDRAULIC POWER TRANSFER UNIT SHUT-OFF (PTU S/O) VALVE DUE TO FAILED (FATIGUED) VALVE BODY ATTACH SCREWS.

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*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=CHI89IA083) · AI Analytics · CC0 1.0*