# NTSB Accident WPR17LA175
> **GRUMMAN AA1** · 2017-08-01 · Phoenix, AZ, USA · SERS
## Event
- **NTSB number:** WPR17LA175
- **Event ID:** 20170801X65228
- **Type:** Accident
- **Date:** 2017-08-01
- **Location:** Phoenix, AZ, USA
- **Coordinates:** 33.686668, -112.099723
## Injuries
- **Highest injury:** SERS
- **Fatal:** 0
- **Serious:** 2
- **Minor:** 0
- **Uninjured:** 0
- **Total aboard:** 2
## Aircraft
- **Make:** GRUMMAN
- **Model:** AA1
- **Registration:** N6216L
- **FAR Part:** 091
- **Engines:** 1
- **Damage:** SUBS
## Conditions
- **Light:** DAYL
- **Weather:** VMC
## Probable cause

The partial loss of engine power during initial climb due to the No. 3 cylinder exhaust valve becoming stuck open due to deposit buildup in the exhaust valve stem and guide and the pilot’s exceedance of the airplane’s critical angle of attack while attempting to turn back to the airport, which resulted in an aerodynamic stall.

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*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=WPR17LA175) · AI Analytics · CC0 1.0*