# NTSB ANC21LA101: Piper PA-18-150, N8987Y, Glennallen, AK, September 1, 2021

- Type: NTSB accident investigation
- Classification: Accident · No injuries · Class 4 · Limited · Final report
- Date: September 1, 2021, 15:00 local (23:00 UTC)
- Place: Glennallen, AK
- Coordinates: 62.333333, -147.67583 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=62.3333&lon=-147.6758&mi=10
- Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping)
- Defining event: [Landing: Abnormal runway contact](https://openairdocs.org/ntsb-events/090)
- 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: FAA
- NTSB case key (mKey): 104475
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC21LA101
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/104475/pdf
- NTSB docket: https://data.ntsb.gov/Docket?ProjectID=104475
- Page: https://openairdocs.org/ntsb/ANC21LA101

## Probable cause

The pilot’s improper landing flare while landing off-airport with a tailwind.

## Findings

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

- [Performance/control parameters: landing flare](https://openairdocs.org/ntsb-findings/01062041): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Piper PA-18-150, 8 cases](https://openairdocs.org/ntsb-findings/01062041/cases.md?model=7101828), [All aircraft, 1,285 cases](https://openairdocs.org/ntsb-findings/01062041/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)
- [Wind: tailwind](https://openairdocs.org/ntsb-findings/03034015): Environmental issues › Conditions/weather/phenomena · Response/compensation; cases with it: [Piper PA-18-150, 15 cases](https://openairdocs.org/ntsb-findings/03034015/cases.md?model=7101828), [All aircraft, 594 cases](https://openairdocs.org/ntsb-findings/03034015/cases.md)

## Sequence of events

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

- [Landing: Abnormal runway contact](https://openairdocs.org/ntsb-events/090) (defining event); cases with it: [Piper PA-18-150, 15 cases](https://openairdocs.org/ntsb-events/090/sequence.md?model=7101828), [All aircraft, 1,506 cases](https://openairdocs.org/ntsb-events/090/sequence.md)

## Analysis

The pilot reported that before landing on an unimproved airstrip, he tried to identify the wind direction using a ribbon located at the high point along the airstrip that was above the treetops. He also over flew the airstrip both ways at about 1,500 ft to verify what the ribbon was showing. During the landing, the airplane was not aligned with the airstrip, and the left main landing gear touched down first, which imposed a significate side load to the left main landing gear assembly. After the landing, the pilot noticed that he had landed with a quartering tailwind. The airplane sustained substantial damage to the fuselage and right-wing rear spar. The pilot reported no preimpact mechanical failures or malfunctions with the airplane that would have precluded normal operation.

## Aircraft

- Registration: [N8987Y](https://openairdocs.org/aircraft/N8987Y), registered now, S/N 18-7409132, built 1974 (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: 18-7409132
- Year built: 1974
- Airframe hours: 2199.9
- Engines: LYCOMING O-320 A2B 160 horsepower reciprocating
- Damage: Substantial damage
- Flight: Personal, Part 91
- Airworthiness certificate: Standard, Normal
- Last inspection: Annual, October 13, 2020
- Departed: PAQ, Palmer, AK
- Destination: Same as departure
- Equipment: ADS-B

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 45; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review March 27, 2020; seat: front; restraint: 3-point; flight hours: 588.5 total, 588.5 in this make and model

## Weather

- Conditions: Visual (VMC), Day
- Wind: 60° at 4 knots
- Visibility: 10 statute miles
- Lowest ceiling: 9,000 ft overcast
- Temperature: 54 °F, dew point 36 °F
- Altimeter: 29.80 inHg
- Observed at: PAZK, 27 nm away
- METAR: PAZK 012256Z AUTO 06004KT 10SM SCT080 OVC090 12/02 A2980 RMK AO2 SLP113 T01170022

## 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 20210901019619A](https://openairdocs.org/incident/20210901019619A), Sep 1, 2021: Piper PA-18-150, AK, Substantial damage. On September 1, 2021 at approximately 1500 local time, N8987Y piloted [privacy data omitted]departed palmer airport after refueling for the purposes of a…

## Other investigations on N8987Y (1)

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 ANC20CA056](https://openairdocs.org/ntsb/ANC20CA056), Jun 2, 2020: Piper PA18 (N8987Y), Nikiski, AK, substantial damage. Probable cause: The pilot's failure to maintain directional control during landing in gusting wind conditions, which resulted in a ground loop.

## Docket (4 files)

The files NTSB released with the investigation on March 21, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=104475. 5.2 MB in all.

- Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 4.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13132916&FileExtension=pdf&FileName=6120_Redacted-Rel.pdf
- Pilot statement (item 2, PDF, 1 page, 465 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13132906&FileExtension=pdf&FileName=Pilot%20Statement%20N8987Y%20Inc-Acc%20event-Rel.pdf
- Pilot roc (item 3, PDF, 1 page, 151 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13137534&FileExtension=pdf&FileName=Pilot%20ROC-Rel.pdf
- Accident picture (item 4, PDF, 1 page, 179 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13132831&FileExtension=pdf&FileName=Accident%20Picture-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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