# NTSB Accident CHI89FA183
> **McDonnell Douglas MD-80** · 1989-09-12 · CHICAGO, IL, USA · MINR
## Event
- **NTSB number:** CHI89FA183
- **Event ID:** 20001213X29315
- **Type:** Accident
- **Date:** 1989-09-12
- **Location:** CHICAGO, IL, USA
## Injuries
- **Highest injury:** MINR
- **Fatal:** 0
- **Serious:** 0
- **Minor:** 2
- **Uninjured:** 108
- **Total aboard:** 110
## Aircraft
- **Make:** McDonnell Douglas
- **Model:** MD-80
- **Registration:** N244AA
- **FAR Part:** 121
- **Engines:** 2
- **Damage:** SUBS
## Conditions
- **Light:** NDRK
- **Weather:** VMC
## Probable cause

A LOSS OF HYDRAULIC SYSTEM PRESSURE DUE TO THE OPERATOR'S FAILURE TO REPLACE A SYSTEM COMPONENT THAT HAD A KNOWN HISTORY OF FAILURES, AND THE PILOT'S IMPROPER USE POWERPLANT CONTROLS RESULTING IN A DEGRADATION OF RUDDER EFFECTIVENESS. A CONTRIBUTING FACTOR WAS THE FAILURE OF THE POWER TRANSFER UNIT SHUTOFF VALVE.

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*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=CHI89FA183) · AI Analytics · CC0 1.0*