# NTSB WPR22LA139: Aviat A-1B, N35AH, Swan Valley, ID, March 30, 2022 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: March 30, 2022, 12:00 local (18:00 UTC) - Place: Swan Valley, ID · Private air strip - Coordinates: 43.51958, -111.38095 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=43.5196&lon=-111.3809&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-landing roll: 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: Western Pacific Region - Parties: FAA - NTSB case key (mKey): 104881 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=WPR22LA139 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/104881/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=104881 - Page: https://openairdocs.org/ntsb/WPR22LA139 ## Probable cause The pilot’s failure to maintain airplane control during the landing roll on a snow-covered runway surface. ## 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: [Aviat A-1B, 3 cases](https://openairdocs.org/ntsb-findings/02041510/cases.md?model=2210406), [All aircraft, 559 cases](https://openairdocs.org/ntsb-findings/02041510/cases.md) - [Runway/land/takeoff/taxi surface: snow/slush/ice covered surface](https://openairdocs.org/ntsb-findings/03023015): Environmental issues › Physical environment · Effect on equipment; cases with it: [Aviat A-1B, 2 cases](https://openairdocs.org/ntsb-findings/03023015/cases.md?model=2210406), [All aircraft, 219 cases](https://openairdocs.org/ntsb-findings/03023015/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Aviat A-1B, 33 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=2210406), [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. - [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230) (defining event); cases with it: [Aviat A-1B, 24 cases](https://openairdocs.org/ntsb-events/230/sequence.md?model=2210406), [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: [Aviat A-1B, 19 cases](https://openairdocs.org/ntsb-events/096/sequence.md?model=2210406), [All aircraft, 2,287 cases](https://openairdocs.org/ntsb-events/096/sequence.md) ## Analysis The pilot reported that, during a landing on a snow-covered, private grass airstrip, he did not adequately confirm the landing surface condition. Subsequently, as the airplane slowed down during the landing roll, the landing gear penetrated through a shallow layer of hard packed snow and then dug into several inches of snow, which caused the airplane to nose over. The airplane sustained substantial damage to the right wing. The pilot reported no preaccident malfunctions or failures with the airplane that would have precluded normal operation. ## Aircraft - Registration: [N35AH](https://openairdocs.org/aircraft/N35AH), registered now, S/N 2417, built 2007 (OpenAirDocs) - Reported make and model: AVIAT AIRCRAFT INC A-1B - Registry model: [Aviat A-1B](https://openairdocs.org/model/aviat-a-1b) (registry code 2210406) (OpenAirDocs) - Registry engine: [Lycoming IO-360-A1D6](https://openairdocs.org/engine/lycoming-io-360-a1d6) (registry code 41822, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 2417 - Year built: 2007 - Airframe hours: 1082 - Engines: Lycoming IO-360-A1D6 200 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Registered owner: K9 Air LLC - Airworthiness certificate: Standard, Normal - Last inspection: Annual, April 1, 2021 - Departed: IDA, Idaho Falls, ID - Airport: PVT, Diamond AIrstrip, runway 10/28, 2,000 × 90 ft, snow - Equipment: Electronic primary flight display, Onboard weather, Electronic flight bag or handheld device, ADS-B, Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 65; injuries: minor; commercial; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review June 15, 2021; seat: front; restraint: 5-point; flight hours: 1,955 total, 443 in this make and model, 1,894 as pilot in command, 13.6 in the last 90 days, 7 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 70° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 37 °F, dew point 19 °F - Altimeter: 30.00 inHg - Observed at: KDIJ, 18 nm away - METAR: KDIJ 301856Z AUTO 07004KT 10SM CLR 03/M07 A3000 RMK AO2 SLP178 T00331067 ## 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 20220330004459A](https://openairdocs.org/incident/20220330004459A), Mar 30, 2022: Aviat Aircraft Inc A-1B, Swan Valley, ID, Substantial damage. The commercial rated pilot stated that he had landed frequently before at the snow-covered private strip. The airplane was equipped with tundra tires, and he… ## Other investigations on N35AH (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 GAA19CA325](https://openairdocs.org/ntsb/GAA19CA325), Jun 9, 2019: Aviat A1 (N35AH), Pingree, ID, substantial damage. Probable cause: The pilot's improper rudder application during landing on a dirt airstrip, which resulted in a loss of directional control, runway excursion, and subsequent nose-over ## Docket (2 files) The files NTSB released with the investigation on June 30, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=104881. 4.6 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 4.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13790898&FileExtension=pdf&FileName=NTSB%206120_1_Redacted-Rel.pdf - Accident pictures (item 2, PDF, 2 pages, 453 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13791026&FileExtension=pdf&FileName=WPR22LA139%20Accident%20Pictures-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.