# NTSB ANC23LA066: Piper PA-18-150, N3995Z, Tyonek, AK, August 15, 2023

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Class 4 · Limited · Final report
- Date: August 15, 2023, 13:30 local (21:30 UTC)
- Place: Tyonek, AK · South Twin Strip
- Coordinates: 61.405506, -151.71058
- Nearby events: https://openairdocs.org/map.md?lat=61.4055&lon=-151.7106&mi=10
- Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping)
- Defining event: [Takeoff: Dragged wing/rotor/float/other](https://openairdocs.org/ntsb-events/093)
- Highest injury: No injuries
- Injuries: 2 uninjured
- Status: Completed
- Report: Approved by Office Director
- Investigation class: Class 4 - Basic report with no Prelim publish
- NTSB office: Alaska Regional Office
- Parties: Federal Aviation Administration (FAA)
- NTSB case key (mKey): 192958
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC23LA066
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/192958/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=192958
- Page: https://openairdocs.org/ntsb/ANC23LA066

## Probable cause

The pilot’s encounter with windshear during the initial climb, which resulted in a loss of control.

## Findings

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

- [Info processing/decision: identification/recognition](https://openairdocs.org/ntsb-findings/02041510): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Piper PA-18-150, 8 cases](https://openairdocs.org/ntsb-findings/02041510/cases.md?model=7101828), [All aircraft, 559 cases](https://openairdocs.org/ntsb-findings/02041510/cases.md)
- [Planning/preparation: weather planning](https://openairdocs.org/ntsb-findings/02061020): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Piper PA-18-150, 5 cases](https://openairdocs.org/ntsb-findings/02061020/cases.md?model=7101828), [All aircraft, 156 cases](https://openairdocs.org/ntsb-findings/02061020/cases.md)
- [Performance/control parameters: climb rate](https://openairdocs.org/ntsb-findings/01062035): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Piper PA-18-150, 3 cases](https://openairdocs.org/ntsb-findings/01062035/cases.md?model=7101828), [All aircraft, 265 cases](https://openairdocs.org/ntsb-findings/01062035/cases.md)
- [Wind: windshear](https://openairdocs.org/ntsb-findings/03034020): Environmental issues › Conditions/weather/phenomena · Contributed to outcome; 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)

## Sequence of events

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

- [Takeoff: Dragged wing/rotor/float/other](https://openairdocs.org/ntsb-events/093) (defining event); cases with it: [Piper PA-18-150, 7 cases](https://openairdocs.org/ntsb-events/093/sequence.md?model=7101828), [All aircraft, 319 cases](https://openairdocs.org/ntsb-events/093/sequence.md)

## Analysis

The pilot reported that, during climb-out from a remote airstrip, he encountered an abrupt wind shift and windshear. According to the pilot, the airplane was unable to gain altitude and was eventually “forced” into the ground, causing substantial damage to the left wing, left horizontal stabilizer, and fuselage. The pilot reported that there were no pre-accident mechanical failures or malfunctions with the airplane that would have precluded normal operation.

## Aircraft

- Registration: [N3995Z](https://openairdocs.org/aircraft/N3995Z), registered now, S/N 18-7944, built 1963 (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: 18-7944
- Year built: 1963
- Airframe hours: 7524.1
- Engines: Lycoming O-320 150 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, April 15, 2023, 56.1 hours before
- Destination: PABV, Chugiak, AK
- Equipment: ADS-B, Handheld GPS, Satellite tracking device

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 63; injuries: none; private; airplane ratings: single-engine land; medical: class 3, without waivers/limitations; last flight review September 24, 2022; seat: front; flight hours: 596 total, 545.8 in this make and model, 524 as pilot in command

## Weather

- Conditions: Visual (VMC), Day
- Wind: 30° at 3 knots
- Visibility: 10 statute miles
- Lowest ceiling: 20,000 ft broken
- Temperature: 61 °F, dew point 52 °F
- Altimeter: 29.78 inHg
- Observed at: ANC, 36 nm away
- METAR: PANC 152053Z 03003KT 10SM FEW010 SCT120 BKN200 16/11 A2978 RMK AO2 SLP084 T01560106 58010

## 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 20230815012189A](https://openairdocs.org/incident/20230815012189A), Aug 15, 2023: Piper PA-18-150, Tyonek, AK, Substantial damage. PIC and passenger were taking off from a 600-700 foot makeshift airstrip in the Alaska range. Visability was approximately 20 miles with the ceiling be about…

## Other investigations on N3995Z (3)

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.

- [NTSB ANC69D0124](https://openairdocs.org/ntsb/ANC69D0124), Apr 14, 1969: Piper PA-18 (N3995Z), Kotzebue, AK, substantial damage
- [NTSB ANC69D0081](https://openairdocs.org/ntsb/ANC69D0081), Apr 24, 1968: Piper PA-18 (N3995Z), King Salmon, AK, substantial damage
- [NTSB UNK64X3270](https://openairdocs.org/ntsb/UNK64X3270), Aug 8, 1964: Piper PA-18 (N3995Z), Fairbank, AZ, destroyed

## Docket (2 files)

The files NTSB released with the investigation on April 4, 2024, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=192958. 4.0 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 10 pages, 3.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16315201&FileExtension=pdf&FileName=6120%20(2)%20Redacted-Rel.pdf
- Photos (item 2, PDF, 5 pages, 620 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=16314194&FileExtension=pdf&FileName=ANC23LA066%20Photos-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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