# NTSB Accident MIA91LA113
> **BELL UH-1B** · 1991-03-12 · VERO BEACH, FL, USA · MINR
## Event
- **NTSB number:** MIA91LA113
- **Event ID:** 20001212X16669
- **Type:** Accident
- **Date:** 1991-03-12
- **Location:** VERO BEACH, FL, USA
- **Coordinates:** 27.720767, -80.390823
## Injuries
- **Highest injury:** MINR
- **Fatal:** 0
- **Serious:** 0
- **Minor:** 1
- **Uninjured:** 0
- **Total aboard:** 1
## Aircraft
- **Make:** BELL
- **Model:** UH-1B
- **Registration:** N9687R
- **FAR Part:** 137
- **Engines:** 1
- **Damage:** SUBS
## Conditions
- **Light:** DAYL
- **Weather:** VMC
## Probable cause

IMPROPER MAINTENANCE ADJUSTMENT BY COMPANY MAINTENANCE PERSONNEL RESULTING IN OVERTORQUE OF A TAILBOOM ATTACH BOLT WHICH ALLOWED THE TAILBOOM TO SHIFT.  THIS DISENGAGED THE TAIL ROTOR DRIVE SHAFT AT A COUPLING RESULTING IN THE LOSS OF TAIL ROTOR DRIVE.

---
*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=MIA91LA113) · AI Analytics · CC0 1.0*