# NTSB ANC21LA044: Piper PA-18-150, N4323Z, Perryville, AK, May 28, 2021

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Class 4 · Limited · Final report
- Date: May 28, 2021, 09:00 local (17:00 UTC)
- Place: Perryville, AK
- Coordinates: 56.076912, -159.67982
- Nearby events: https://openairdocs.org/map.md?lat=56.0769&lon=-159.6798&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Defining event: [Takeoff: Windshear or thunderstorm](https://openairdocs.org/ntsb-events/390)
- Highest injury: No injuries
- Injuries: 1 uninjured
- Status: Completed
- Report: Approved by Office Director
- Investigation class: Class 4 - Basic report with no Prelim publish
- NTSB office: Alaska Regional Office
- NTSB case key (mKey): 103228
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC21LA044
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103228/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103228
- Page: https://openairdocs.org/ntsb/ANC21LA044

## Probable cause

The airplane’s encounter with windshear on takeoff, which resulted in a loss of control and impact with the ground.

## Findings

NTSB's coded findings; those marked are part of the probable cause.

- [Wind: windshear](https://openairdocs.org/ntsb-findings/03034020): Environmental issues › Conditions/weather/phenomena · Effect on equipment (probable cause); cases with it: [Piper PA-18-150, 3 cases](https://openairdocs.org/ntsb-findings/03034020/cases.md?model=7101828), [All aircraft, 90 cases](https://openairdocs.org/ntsb-findings/03034020/cases.md)
- [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Piper PA-18-150, 160 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=7101828), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md)

## Sequence of events

The events NTSB coded, in order, by phase of flight. The defining event best describes what happened.

- [Takeoff: Windshear or thunderstorm](https://openairdocs.org/ntsb-events/390) (defining event); cases with it: [Piper PA-18-150, 3 cases](https://openairdocs.org/ntsb-events/390/sequence.md?model=7101828), [All aircraft, 224 cases](https://openairdocs.org/ntsb-events/390/sequence.md)

## Analysis

The pilot reported that, just after takeoff from a remote off-airport landing site, he encountered windshear that pushed the airplane into the tops of alder trees and onto a gravel bar. The airplane sustained substantial damage to the fuselage, right wing and right elevator. The pilot reported no preaccident mechanical failures or malfunctions that would have precluded normal operations.

## Aircraft

- Registration: [N4323Z](https://openairdocs.org/aircraft/N4323Z), registered now, S/N 18-8638 (OpenAirDocs)
- Reported make and model: PIPER PA-18-150
- Registry model: [Piper PA-18-150](https://openairdocs.org/model/piper-pa-18-150) (registry code 7101828) (OpenAirDocs)
- Registry engine: [Lycoming 0-320 series](https://openairdocs.org/engine/lycoming-0-320-series) (registry code 41508, reciprocating) (OpenAirDocs)
- Category: Airplane
- Serial number: 18-8638
- Year built: 1968
- Airframe hours: 1800
- Engines: LYCOMING 0-320 SERIES 160 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Registered owner: Thomas F Watkins
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, June 30, 2021
- Flight plan: VFR
- Equipment: Handheld GPS

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 68; injuries: none; private; airplane ratings: single-engine land; medical: class 3, without waivers/limitations; last flight review April 3, 2020; seat: front; restraint: 4-point; flight hours: 5,200 total, 4,600 in this make and model, 60 in the last 90 days, 20 in the last 30 days, 0 in the last 24 hours

## Weather

- Conditions: Day
- Wind: 30° at 6 knots
- Visibility: 2 statute miles
- Lowest ceiling: 1,200 ft overcast
- Temperature: 45 °F, dew point 43 °F
- Altimeter: 29.55 inHg
- Observed at: PAJC, 46 nm away
- METAR: PAJC 281737Z AUTO 03006KT 2SM -RA BR SCT006 OVC012 07/06 A2955 RMK AO2 RAB31 P0000 $

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 20210528011129A](https://openairdocs.org/incident/20210528011129A), May 28, 2021: Piper PA-18-150, Sandy River, AK, Substantial damage. N4323Z, PA-18, coming out of a pass, windshear pushed the aircraft down and landed on a gravel bar near Sandy River.

## Docket (2 files)

The files NTSB released with the investigation on November 12, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103228. 4.2 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 2.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12431115&FileExtension=pdf&FileName=6120_Redacted-Rel.pdf
- Photo (source unknown) (item 2, PDF, 1 page, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12430923&FileExtension=pdf&FileName=Photo%20array-Rel.pdf

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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