# NTSB GAA19CA487: Cessna 170, N2946D, Bison, SD, July 15, 2019 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: July 15, 2019, 13:40 local (18:40 UTC) - Place: Bison, SD - Coordinates: 45.518333, -102.467781 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=45.5183&lon=-102.4678&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Hard landing](https://openairdocs.org/ntsb-events/092) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report April 13, 2020 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: FAA - NTSB case key (mKey): 100008 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA19CA487 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/100008/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=100008 - Page: https://openairdocs.org/ntsb/GAA19CA487 ## Probable cause The pilot's improper landing flare, which resulted in a hard landing and subsequent ground loop. ## 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: [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: [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Performance/control parameters: landing flare](https://openairdocs.org/ntsb-findings/01062041): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [All aircraft, 1,285 cases](https://openairdocs.org/ntsb-findings/01062041/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing: Hard landing](https://openairdocs.org/ntsb-events/092) (defining event); cases with it: [All aircraft, 2,102 cases](https://openairdocs.org/ntsb-events/092/sequence.md) - [Landing-landing roll: Loss of control on ground](https://openairdocs.org/ntsb-events/230); cases with it: [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) ## Analysis The pilot reported that, upon landing, the airplane veered left. He attempted to correct with rudder and tapping on the brakes, but the airplane ground looped. The pilot added that he believed that "the landing gear was out of alignment." The airplane sustained substantial damage to the fuselage and the windscreen. According to a Federal Aviation Administration inspector, the fuselage damage was consistent with a hard landing and ground loop. ## Factual narrative The pilot of a recently purchased tailwheel-equipped airplane reported that, upon landing, the airplane veered left. He attempted to correct with rudder and tapping on the brakes, but the aircraft ground looped. The pilot further reported that he believed that "the landing gear was out of alignment." Photos of the fuselage damage, provided by the FAA inspector, are consistent with a hard landing and ground loop. The FAA inspector further identified the last annual inspection was conducted on October 1, 2014. The airplane sustained substantial damage to the fuselage and wind screen. An automated weather observation station located 31 miles to the north, reported that, about the time of the accident, the wind was from 220° at 3 knots. The airplane was landing on runway 29. ## Aircraft - Registration: N2946D (not matched to a registry record) - Reported make and model: Cessna 170 (B) - Category: Airplane - Serial number: 26889 - Year built: 1955 - Airframe hours: 2990 - Engines: Continental O-300 145 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, November 1, 2014 - Departed: 6V5, Bison, SD - Destination: 6V5, Bison, SD - Airport: 6V5, Bison Muni, runway 29, 3,500 × 60 ft, asphalt - Equipment: Handheld GPS ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 75; injuries: none; private; airplane ratings: single-engine land; medical: basicmed; last flight review April 12, 2018; seat: left; flight hours: 3,500 total, 7 in this make and model ## Weather - Conditions: Visual (VMC), Day - Wind: 220° at 3 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 88 °F, dew point 64 °F - Altimeter: 29.94 inHg - Observed at: KHEI, 31 nm away ## Docket (3 files) The files NTSB released with the investigation on October 23, 2019, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=100008. 1.0 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 657 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40477036&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Record of Phone Conversation (item 2, .PDF, 94 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40477037&FileExtension=.PDF&FileName=Record%20of%20Phone%20Conversation-Master.PDF - Accident Photos (item 3, .PDF, 2 photos, 271 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40477038&FileExtension=.PDF&FileName=Accident%20Photos-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.