# NTSB GAA18CA090: Piper PA22, N4805Z, Yentna, AK, December 18, 2017 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: December 18, 2017, 13:00 local (22:00 UTC) - Place: Yentna, AK - Coordinates: 61.731388, -150.672225 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=61.7314&lon=-150.6722&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Loss of control on ground](https://openairdocs.org/ntsb-events/230) - Highest injury: No injuries - Injuries: 2 uninjured - Status: Completed, report March 27, 2018 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 96515 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA18CA090 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/96515/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=96515 - Page: https://openairdocs.org/ntsb/GAA18CA090 ## Probable cause The pilot’s selection of unsuitable terrain for landing, which resulted in a loss of directional control and subsequent nose-over. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Performance/control parameters: directional control](https://openairdocs.org/ntsb-findings/01062020): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Piper PA-22-108, 8 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md?model=7102204), [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/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-22-108, 12 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=7102204), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Info processing/decision: decision making/judgment](https://openairdocs.org/ntsb-findings/02041520): Personnel issues › Action/decision · Pilot (probable cause); cases with it: [Piper PA-22-108, 7 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md?model=7102204), [All aircraft, 3,098 cases](https://openairdocs.org/ntsb-findings/02041520/cases.md) - [Terrain: snowy/icy terrain](https://openairdocs.org/ntsb-findings/03021030): Environmental issues › Physical environment · Decision related to condition (probable cause); cases with it: [Piper PA-22-108, 1 case](https://openairdocs.org/ntsb-findings/03021030/cases.md?model=7102204), [All aircraft, 77 cases](https://openairdocs.org/ntsb-findings/03021030/cases.md) - [Runway/land/takeoff/taxi surface: soft surface](https://openairdocs.org/ntsb-findings/03023020): Environmental issues › Physical environment · Effect on operation; cases with it: [Piper PA-22-108, 2 cases](https://openairdocs.org/ntsb-findings/03023020/cases.md?model=7102204), [All aircraft, 264 cases](https://openairdocs.org/ntsb-findings/03023020/cases.md) - [Terrain: snowy/icy terrain](https://openairdocs.org/ntsb-findings/03021030): Environmental issues › Physical environment · Effect on operation; cases with it: [Piper PA-22-108, 1 case](https://openairdocs.org/ntsb-findings/03021030/cases.md?model=7102204), [All aircraft, 77 cases](https://openairdocs.org/ntsb-findings/03021030/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing: Miscellaneous/other](https://openairdocs.org/ntsb-events/900); cases with it: [Piper PA-22-108, 2 cases](https://openairdocs.org/ntsb-events/900/sequence.md?model=7102204), [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md) - [Landing: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [Piper PA-22-108, 11 cases](https://openairdocs.org/ntsb-events/230/sequence.md?model=7102204), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Landing: Nose over/nose down](https://openairdocs.org/ntsb-events/096); cases with it: [Piper PA-22-108, 8 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=7102204), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot of the tailwheel-equipped airplane reported that, while landing on an unimproved snow-covered airstrip, the left main tire dug into snow, and the airplane veered left. Subsequently, the airplane sank in the softer snow off the left side of the airstrip and nosed over. The airplane sustained substantial damage to the right wing. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. ## Factual narrative The pilot of the tailwheel-equipped airplane reported that, while landing on an unimproved snow-covered airstrip, the left main tire dug into snow and the airplane veered left. Subsequently, the airplane sank in the softer snow off the left side of the airstrip and nosed over. The airplane sustained substantial damage to the right wing. The pilot reported that there were no preaccident mechanical failures or malfunctions with the airplane that would have precluded normal operation. ## Aircraft - Registration: [N4805Z](https://openairdocs.org/aircraft/N4805Z), registered now, S/N 22-8372 (OpenAirDocs) - Reported make and model: PIPER PA22 (108) - Registry model: [Piper PA-22-108](https://openairdocs.org/model/piper-pa-22-108) (registry code 7102204) (OpenAirDocs) - Registry engine: [Lycoming 0-235 series](https://openairdocs.org/engine/lycoming-0-235-series) (registry code 41505, 4 cycle) (OpenAirDocs) - Category: Airplane - Serial number: 22-8372 - Year built: 1961 - Airframe hours: 1583.5 - Engines: LYCOMING O-235 SERIES 108 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 8, 2017 - Departed: PAQ, PALMER, AK - Destination: 0AK2, Yentna, AK - Airport: 0AK2, Yentna Bend Strip, runway 3, 1,500 × 50 ft, snow - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 27; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review June 28, 2017; seat: left; restraint: lap only; flight hours: 87 total, 2 in this make and model, 60 as pilot in command, 5 in the last 90 days, 1 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: -0 °F, dew point -6 °F - Altimeter: 30.18 inHg - Observed at: PATK, 39 nm away ## 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 20171218023259A](https://openairdocs.org/incident/20171218023259A), Dec 18, 2017: Piper PA-22-108, Yentna, AK, Substantial damage. Departed palmer (paaq) at approximately 1200L and arrived Yentna Station (02AK) at approximately 1300L. Pilot stated that he overflew the runway to check… ## Docket (2 files) The files NTSB released with the investigation on February 14, 2018, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=96515. 1.2 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 941 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40460031&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Accident Photo (Courtesy of Pilot) (item 2, .PDF, 1 photo, 297 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40460032&FileExtension=.PDF&FileName=Accident%20Photo%20(Courtesy%20of%20Pilot)-Master.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.