# NTSB Accident CHI89FA071
> **SIKORSKY S-58T** · 1989-04-11 · MILWAUKEE, WI, USA · SERS
## Event
- **NTSB number:** CHI89FA071
- **Event ID:** 20001213X28056
- **Type:** Accident
- **Date:** 1989-04-11
- **Location:** MILWAUKEE, WI, USA
- **Coordinates:** 42.980186, -87.900184
## Injuries
- **Highest injury:** SERS
- **Fatal:** 0
- **Serious:** 1
- **Minor:** 0
- **Uninjured:** 0
- **Total aboard:** 1
## Aircraft
- **Make:** SIKORSKY
- **Model:** S-58T
- **Registration:** N4247U
- **FAR Part:** 133
- **Engines:** 2
- **Damage:** SUBS
## Conditions
- **Light:** DAYL
- **Weather:** VMC
## Probable cause

DISCONNECT OF THE TAILROTOR DRIVE SHAFT COUPLING.

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*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=CHI89FA071) · AI Analytics · CC0 1.0*