# NTSB ANC22LA034: Cessna 170B, N2692D, Big Lake, AK, May 21, 2022 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: May 20, 2022, 17:30 local (May 21, 2022, 01:30 UTC) - Place: Big Lake, AK - Coordinates: 61.569515, -149.85473 - Nearby events: https://openairdocs.org/map.md?lat=61.5695&lon=-149.8547&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-flare/touchdown: Loss of control in flight](https://openairdocs.org/ntsb-events/240) - 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: FAA - NTSB case key (mKey): 105111 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ANC22LA034 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/105111/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=105111 - Page: https://openairdocs.org/ntsb/ANC22LA034 ## Probable cause The pilot's failure to maintain adequate airspeed during final approach which resulted in the airplane exceeding its critical angle of attack and a subsequent aerodynamic stall at too low of an altitude to recover. ## 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) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause) - [Performance/control parameters: airspeed](https://openairdocs.org/ntsb-findings/01062010): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause) - [Performance/control parameters: angle of attack](https://openairdocs.org/ntsb-findings/01062042): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause) ## Analysis The pilot reported that, while on final approach to landing at a private airstrip, he was slow to correct for a slower-than-normal airspeed. Subsequently, the airplane entered an aerodynamic stall, and descended into a swampy area short of the runway. The airplane sustained substantial damage to the wings. The pilot reported that there were no preaccident mechanical malfunctions or failures with the airplane that would have precluded normal operation. ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-flare/touchdown: Loss of control in flight](https://openairdocs.org/ntsb-events/240) (defining event) ## Aircraft - Registration: [N2692D](https://openairdocs.org/aircraft/N2692D), registered now, S/N 20844, built 1952 (OpenAirDocs) - Reported make and model: CESSNA 170B - Registry model: [Cessna 170B](https://openairdocs.org/model/cessna-170b) (registry code 2072306) (OpenAirDocs) - Registry engine: [Continental C145 series](https://openairdocs.org/engine/continental-c145-series) (registry code 17012, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 20844 - Year built: 1952 - Airframe hours: 4424.4 - Engines: Continental O-300 145 hp reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 19, 2022, 0.5 hours before - Destination: PAGQ, Big Lake, AK - Airport: PAGQ, Big Lake Airport, runway 070, 800 × 60 ft, dirt - Equipment: None ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 60; injuries: none; commercial; instrument ratings: helicopter; medical: class 3, with waivers/limitations; seat: left; restraint: lap only; flight hours: 3,920 total, 27 in this make and model, 2,905 as pilot in command, 1 in the last 90 days, 1 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 190° at 6 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 70 °F, dew point 30 °F - Altimeter: 30.30 inHg - Observed at: PAWS, 9 nm away - METAR: PAWS 210156Z AUTO 19006KT 10SM CLR 21/M01 A3030 RMK AO2 SLP264 T02111006 ## 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 20220520007399A](https://openairdocs.org/incident/20220520007399A), May 20, 2022: Cessna 170B, Big Lake, AK, Substantial damage. Upon approach to land with a right-rear quartering tailwind, aircraft began to drift left. Aircraft was already below treeline directly in front of aircraft.… ## Other investigations on N2692D (1) From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model. - [NTSB ANC98LA041](https://openairdocs.org/ntsb/ANC98LA041), Apr 25, 1998: Cessna 170B (N2692D), Kenai, AK, substantial damage. Probable cause: A failure of the number six cylinder rod bearing and connecting rod cap for undetermined reasons. Factors in the accident were snow covered terrain that was unsuitable for a forced landing. ## Docket (2 files) The files NTSB released with the investigation on October 20, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=105111. 2.8 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14604336&FileExtension=pdf&FileName=ANC22LA034%20PDF%20Print%206020_Redacted-Rel-Rel.pdf - Photos (item 2, PDF, 3 pages, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=13960681&FileExtension=pdf&FileName=Photo%20Array%20ANC22LA034-Rel.pdf From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date; 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.