# NTSB Accident DEN99LA173
> **Enstrom 280C** · 1999-09-30 · LONGMONT, CO, USA · NONE
## Event
- **NTSB number:** DEN99LA173
- **Event ID:** 20001212X19750
- **Type:** Accident
- **Date:** 1999-09-30
- **Location:** LONGMONT, CO, USA
- **Coordinates:** 40.169178, -105.109924
## Injuries
- **Highest injury:** NONE
- **Fatal:** 0
- **Serious:** 0
- **Minor:** 0
- **Uninjured:** 1
- **Total aboard:** 1
## Aircraft
- **Make:** Enstrom
- **Model:** 280C
- **Registration:** N84DH
- **FAR Part:** 091
- **Engines:** 1
- **Damage:** SUBS
## Conditions
- **Light:** DAYL
- **Weather:** VMC
## Probable cause

An inaccurate touchdown during a full autorotation, which resulted in main rotor flex which cut off the tail boom. Factors were the pilot's lack of total experience in helicopters and high density altitude.

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*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=DEN99LA173) · AI Analytics · CC0 1.0*