# NTSB Accident ERA14FA421
> **KLAAS DEVELOPMENT INC LANCAIR IV P** · 2014-09-03 · Ooltewah, TN, USA · FATL
## Event
- **NTSB number:** ERA14FA421
- **Event ID:** 20140903X63615
- **Type:** Accident
- **Date:** 2014-09-03
- **Location:** Ooltewah, TN, USA
- **Coordinates:** 35.077777, -85.055274
## Injuries
- **Highest injury:** FATL
- **Fatal:** 1
- **Serious:** 0
- **Minor:** 0
- **Uninjured:** 0
- **Total aboard:** 1
## Aircraft
- **Make:** KLAAS DEVELOPMENT INC
- **Model:** LANCAIR IV P
- **Registration:** N541EM
- **FAR Part:** 091
- **Engines:** 1
- **Damage:** SUBS
## Conditions
- **Light:** DAYL
- **Weather:** VMC
## Probable cause

The inadequate torque of the propeller mounting bolts and inspection of the propeller, which resulted in the fatigue fracture of the bolts and a subsequent in-flight separation of the propeller assembly.

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*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=ERA14FA421) · AI Analytics · CC0 1.0*