# NTSB Incident FTW91IA143
> **Bell 412** · 1991-08-08 · ROWAN MIDLAND · NONE
## Event
- **NTSB number:** FTW91IA143
- **Event ID:** 20001212X17863
- **Type:** Incident
- **Date:** 1991-08-08
- **Location:** ROWAN MIDLAND
## Injuries
- **Highest injury:** NONE
- **Fatal:** 0
- **Serious:** 0
- **Minor:** 0
- **Uninjured:** 15
- **Total aboard:** 15
## Aircraft
- **Make:** Bell
- **Model:** 412
- **Registration:** N177EH
- **FAR Part:** 135
- **Engines:** 2
- **Damage:** —
## Conditions
- **Light:** DAYL
- **Weather:** VMC
## Probable cause

THE MECHANIC'S FAILURE TO ASSEMBLE THE TAIL ROTOR DRIVE SHAFT CORRECTLY AND THE SUBSEQUENT FAILURE OF THE TAIL ROTOR DRIVE SHAFT. A FACTOR WAS THE LACK OF INSPECTION PROCEDURES FOR OFFSHORE MAINTENANCE.

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*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=FTW91IA143) · AI Analytics · CC0 1.0*