# NTSB Accident CEN12FA100
> **CESSNA 421C** · 2011-12-09 · Sioux Falls, SD, USA · FATL
## Event
- **NTSB number:** CEN12FA100
- **Event ID:** 20111209X74224
- **Type:** Accident
- **Date:** 2011-12-09
- **Location:** Sioux Falls, SD, USA
- **Coordinates:** 43.592224, -96.751945
## Injuries
- **Highest injury:** FATL
- **Fatal:** 4
- **Serious:** 0
- **Minor:** 0
- **Uninjured:** 0
- **Total aboard:** 4
## Aircraft
- **Make:** CESSNA
- **Model:** 421C
- **Registration:** N421SY
- **FAR Part:** 135
- **Engines:** 2
- **Damage:** SUBS
## Conditions
- **Light:** DAYL
- **Weather:** VMC
## Probable cause

The pilot’s failure to maintain adequate airspeed after shutting down one engine, which resulted in an inadvertent aerodynamic stall and impact with terrain. Contributing to the accident was the pilot’s failure to follow the guidance contained in the pilot’s operating handbook, which advised feathering the propeller of the secured engine and retracting the flaps and landing gear.

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*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=CEN12FA100) · AI Analytics · CC0 1.0*