# NTSB Accident WPR10TA025
> **MCDONNELL DOUGLAS HELICOPTER 500N** · 2009-10-16 · Los Alamitos, CA, USA · NONE
## Event
- **NTSB number:** WPR10TA025
- **Event ID:** 20091020X30424
- **Type:** Accident
- **Date:** 2009-10-16
- **Location:** Los Alamitos, CA, USA
- **Coordinates:** 33.79, -118.051391
## Injuries
- **Highest injury:** NONE
- **Fatal:** 0
- **Serious:** 0
- **Minor:** 0
- **Uninjured:** 2
- **Total aboard:** 2
## Aircraft
- **Make:** MCDONNELL DOUGLAS HELICOPTER
- **Model:** 500N
- **Registration:** N521HB
- **FAR Part:** 091
- **Engines:** 1
- **Damage:** SUBS
## Conditions
- **Light:** DAYL
- **Weather:** VMC
## Probable cause

The flight instructor's delayed remedial action during the instructional autorotative landing, which resulted in a failure to maintain an adequate rotor rpm to avoid a hard landing.

---
*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=WPR10TA025) · AI Analytics · CC0 1.0*