# NTSB Accident SEA92LA029
> **AEROSPATIALE AS355F1** · 1991-10-29 · BILLINGS, MT, USA · NONE
## Event
- **NTSB number:** SEA92LA029
- **Event ID:** 20001212X18400
- **Type:** Accident
- **Date:** 1991-10-29
- **Location:** BILLINGS, MT, USA
- **Coordinates:** 45.870731, -108.470985
## Injuries
- **Highest injury:** NONE
- **Fatal:** 0
- **Serious:** 0
- **Minor:** 0
- **Uninjured:** 3
- **Total aboard:** 3
## Aircraft
- **Make:** AEROSPATIALE
- **Model:** AS355F1
- **Registration:** N101UC
- **FAR Part:** 091
- **Engines:** 2
- **Damage:** SUBS
## Conditions
- **Light:** NDRK
- **Weather:** VMC
## Probable cause

THE UNLATCHING AND SUBSEQUENT OPENING INFLIGHT OF THE LEFT-REAR ENGINE COWL DOOR.  A FACTOR CONTRIBUTING TO THE ACCIDENT WAS THE FAILURE OF COMPANY MAINTENANCE PERSONNEL TO EXECUTE THE MANUFACTURER'S SERVICE BULLETIN.

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*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=SEA92LA029) · AI Analytics · CC0 1.0*