# NTSB Accident DEN89DTM02
> **HILLER UH-12E** · 1989-05-13 · MACK, CO, USA · SERS
## Event
- **NTSB number:** DEN89DTM02
- **Event ID:** 20001213X28284
- **Type:** Accident
- **Date:** 1989-05-13
- **Location:** MACK, CO, USA
- **Coordinates:** 39.219779, -108.870918
## Injuries
- **Highest injury:** SERS
- **Fatal:** 0
- **Serious:** 1
- **Minor:** 0
- **Uninjured:** 0
- **Total aboard:** 1
## Aircraft
- **Make:** HILLER
- **Model:** UH-12E
- **Registration:** N5594N
- **FAR Part:** 137
- **Engines:** 1
- **Damage:** SUBS
## Conditions
- **Light:** DAYL
- **Weather:** VMC
## Probable cause

THE PILOT'S FAILURE TO MAINTAIN PROPER ALTITUDE DURING A SWATH RUN.

---
*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=DEN89DTM02) · AI Analytics · CC0 1.0*