# NTSB Accident WPR09FA234
> **Upton Bakeng Duce** · 2009-05-09 · Ramona, CA, USA · FATL
## Event
- **NTSB number:** WPR09FA234
- **Event ID:** 20090509X02427
- **Type:** Accident
- **Date:** 2009-05-09
- **Location:** Ramona, CA, USA
- **Coordinates:** 32.988609, -116.781944
## Injuries
- **Highest injury:** FATL
- **Fatal:** 2
- **Serious:** 0
- **Minor:** 0
- **Uninjured:** 0
- **Total aboard:** 2
## Aircraft
- **Make:** Upton
- **Model:** Bakeng Duce
- **Registration:** N86YP
- **FAR Part:** 091
- **Engines:** 1
- **Damage:** SUBS
## Conditions
- **Light:** DAYL
- **Weather:** VMC
## Probable cause

An in-flight separation of the right wing, which resulted from the pilot's performance of a maneuver that produced aerodynamic loads that exceeded the wing spar’s degraded strength. The wing spar strength degradation was due to the builder's failure to comply with Federal Aviation Administration recommended guidelines to select and incorporate wood in the spar with a grain pattern aligned with the longitudinal axis of the spar.

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*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=WPR09FA234) · AI Analytics · CC0 1.0*