# NTSB Incident CHI98IA169
> **Douglas DC-9-34** · 1998-04-30 · ST. LOUIS, MO, USA · NONE
## Event
- **NTSB number:** CHI98IA169
- **Event ID:** 20001211X09811
- **Type:** Incident
- **Date:** 1998-04-30
- **Location:** ST. LOUIS, MO, USA
- **Coordinates:** 38.760334, -90.420143
## Injuries
- **Highest injury:** NONE
- **Fatal:** 0
- **Serious:** 0
- **Minor:** 0
- **Uninjured:** 44
- **Total aboard:** 44
## Aircraft
- **Make:** Douglas
- **Model:** DC-9-34
- **Registration:** N928L
- **FAR Part:** 121
- **Engines:** —
- **Damage:** —
## Conditions
- **Light:** NR
- **Weather:** VMC
## Probable cause

the yaw rate gyro of the Stab Aug Computer had been installed in a reverse  position that was 180 degrees opposite from the correct position.

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*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=CHI98IA169) · AI Analytics · CC0 1.0*