# NTSB ANC23LA037: Piper PA-18-150, N4231Z, Hunter Creek, AK, May 20, 2023 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: May 19, 2023, 17:02 local (May 20, 2023, 01:02 UTC) - Place: Hunter Creek, AK · Sand / gravel bar - Coordinates: 61.443797, -148.7007 - Nearby events: https://openairdocs.org/map.md?lat=61.4438&lon=-148.7007&mi=10 - Phase of flight: [Takeoff](https://openairdocs.org/ntsb-phases/300) (OpenAirDocs' grouping) - Defining event: [Takeoff: Loss of control on ground](https://openairdocs.org/ntsb-events/230) - 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 - Parties: Federal Aviation Administration (FAA) - NTSB case key (mKey): 192219 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC23LA037 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/192219/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=192219 - Page: https://openairdocs.org/ntsb/ANC23LA037 ## Probable cause The pilot’s loss of directional control during takeoff roll in gusting wind conditions. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Performance/control parameters: directional control](https://openairdocs.org/ntsb-findings/01062020): Aircraft › Aircraft oper/perf/capability · Unknown/Not determined (probable cause); cases with it: [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md) - [Wind: gusts](https://openairdocs.org/ntsb-findings/03034045): Environmental issues › Conditions/weather/phenomena · Effect on operation (probable cause); cases with it: [All aircraft, 1,199 cases](https://openairdocs.org/ntsb-findings/03034045/cases.md) - [Aircraft capability: maximum crosswind component](https://openairdocs.org/ntsb-findings/01061015): Aircraft › Aircraft oper/perf/capability · Capability exceeded; cases with it: [All aircraft, 21 cases](https://openairdocs.org/ntsb-findings/01061015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Takeoff: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Takeoff: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot reported that during the takeoff roll from a remote gravel bar in a tundra tire-equipped airplane, a gusting crosswind banked the airplane to the right, and it subsequently came to rest inverted and sustained substantial damage to the wings and empennage. The pilot reported that there were no preimpact mechanical malfunctions or failures with the airplane that would have precluded normal operation. At the time of takeoff, the pilot reported the winds to be gusting about 45 to 50 knots, which he said exceeded rudder and aileron authority. ## Aircraft - Registration: N4231Z (not matched to a registry record) - Reported make and model: PIPER PA-18-150 - Category: Airplane - Serial number: 18-8457 - Year built: 1966 - Engines: LYCOMING O-320 SERIES 160 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Utility - Departed: 0AK1, Wasilla, AK - Destination: PVT, Palmer, AK - Airport: PAQ, Palmer Municipal - Equipment: Handheld GPS, Electronic flight bag or handheld device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 35; injuries: none; flight instructor, airline transport, commercial; airplane ratings: multi-engine land, single-engine sea, single-engine land; instrument ratings: helicopter; medical: class 1, with waivers/limitations; last flight review April 18, 2023; seat: front; restraint: 4-point; flight hours: 9,420 total, 714 in this make and model, 122 in the last 90 days, 24 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 140° at 20 knots, gusting 30 - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 63 °F, dew point 39 °F - Altimeter: 29.92 inHg - Observed at: PAAQ, 14 nm away - METAR: PAAQ 200153Z 14020G30KT 10SM CLR 17/04 A2992 RMK AO2 PK WND 14030/0147 SLP134 T01670044 ## 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 20230519007809A](https://openairdocs.org/incident/20230519007809A), May 19, 2023: Piper PA-18-150, Palmer, AK, Substantial damage. Pilot stated he elected to take off from a gravel bar due to extreme winds and blowing dust because he was becoming very concerned that the high winds would… ## Docket (2 files) The files NTSB released with the investigation on October 20, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=192219. 12.2 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 10.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15613536&FileExtension=pdf&FileName=NTSB%20Form%206120_Redacted-Rel.pdf - Photos (item 2, PDF, 4 pages, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15590393&FileExtension=pdf&FileName=Photos-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. --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.