# NTSB Accident ANC17LA007
> **PIPER PA-18** · 2016-11-22 · Bethel, AK, USA · NONE
## Event
- **NTSB number:** ANC17LA007
- **Event ID:** 20161129X63442
- **Type:** Accident
- **Date:** 2016-11-22
- **Location:** Bethel, AK, USA
- **Coordinates:** 61.414722, -161.958053
## Injuries
- **Highest injury:** NONE
- **Fatal:** 0
- **Serious:** 0
- **Minor:** 0
- **Uninjured:** 2
- **Total aboard:** 2
## Aircraft
- **Make:** PIPER
- **Model:** PA-18
- **Registration:** N83641
- **FAR Part:** 091
- **Engines:** 1
- **Damage:** SUBS
## Conditions
- **Light:** DAYL
- **Weather:** VMC
## Probable cause

The mechanic's failure to install a whistle slot in the engine breather tube, which resulted in a frozen tube, displacement of the crankshaft oil seal, a loss of oil, and smoke in the cockpit, which led to a forced landing.

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*Source: [NTSB CAROL](https://data.ntsb.gov/carol-main-public/basic-search?source=ntsb&type=event&ntsb_number=ANC17LA007) · AI Analytics · CC0 1.0*