# NTSB Accident CEN16LA027
> **BELL 407** · 2015-11-03 · San Antonio, TX, USA · NONE
## Event
- **NTSB number:** CEN16LA027
- **Event ID:** 20151104X14945
- **Type:** Accident
- **Date:** 2015-11-03
- **Location:** San Antonio, TX, USA
- **Coordinates:** 29.533889, -98.469169
## Injuries
- **Highest injury:** NONE
- **Fatal:** 0
- **Serious:** 0
- **Minor:** 0
- **Uninjured:** 3
- **Total aboard:** 3
## Aircraft
- **Make:** BELL
- **Model:** 407
- **Registration:** N496AE
- **FAR Part:** 135
- **Engines:** 1
- **Damage:** SUBS
## Conditions
- **Light:** NITE
- **Weather:** VMC
## Probable cause

The failure of the No. 3 tail rotor adapter and shaft due to a loss of torque on the retaining nut. Contributing to the accident was the lack of a requirement to inspect the tail rotor assembly for security in the helicopter manufacturer's maintenance manual and the operator's approved aircraft inspection program.

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*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=CEN16LA027) · AI Analytics · CC0 1.0*