# NTSB ERA20CA171: Mooney M20K, N231DW, Athens, GA, May 3, 2020 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Data collection · Final report - Date: May 3, 2020, 10:50 local (15:50 UTC) - Place: Athens, GA - Coordinates: 33.948612, -83.325836 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.9486&lon=-83.3258&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Landing gear collapse](https://openairdocs.org/ntsb-events/094) - 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: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 101243 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA20CA171 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/101243/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=101243 - Page: https://openairdocs.org/ntsb/ERA20CA171 ## Probable cause The collapse of the left main landing gear for reasons that could not be determined based on the available information. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: gear extension and retract sys](https://openairdocs.org/ntsb-findings/01023230): Aircraft › Aircraft systems · Malfunction (probable cause); cases with it: [Mooney M20K, 2 cases](https://openairdocs.org/ntsb-findings/01023230/cases.md?model=5870220), [All aircraft, 416 cases](https://openairdocs.org/ntsb-findings/01023230/cases.md) - [Not determined](https://openairdocs.org/ntsb-findings/05000000): Not determined › Not determined · Unknown/Not determined (probable cause); cases with it: [Mooney M20K, 4 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md?model=5870220), [All aircraft, 2,247 cases](https://openairdocs.org/ntsb-findings/05000000/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing: Landing gear collapse](https://openairdocs.org/ntsb-events/094) (defining event); cases with it: [Mooney M20K, 3 cases](https://openairdocs.org/ntsb-events/094/sequence.md?model=5870220), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md) ## Analysis According to the pilot, while on approach, he lowered the airplane's landing gear and confirmed that the landing gear was down and locked by observing the panel and floor indicators in the cockpit; however, during the subsequent landing roll, the left main landing gear collapsed. The airplane veered off the left side of the runway into a ditch. Examination of the airplane revealed that the left wingtip spar was buckled, and the torque tubing associated with the left main landing gear was bent and broken. Review of the logbook records did not reveal any recent maintenance on the landing gear system. Due to the damage of the landing gear assembly, a landing gear retraction test or rigging check could not be performed. ## Aircraft - Registration: [N231DW](https://openairdocs.org/aircraft/N231DW), registered now, S/N 25-0144, built 1979 (OpenAirDocs) - Reported make and model: Mooney M20K (No Series) - Registry model: [Mooney M20K](https://openairdocs.org/model/mooney-m20k) (registry code 5870220) (OpenAirDocs) - Registry engine: [Continental TSIO-360 series](https://openairdocs.org/engine/continental-tsio-360-series) (registry code 17019, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 25-0144 - Year built: 1979 - Airframe hours: 6206 - Engines: Continental TSIO-360 SER 210 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, November 2, 2019 - Departed: PDK, Atlanta, GA - Destination: AHN, Athens, GA - Airport: AHN, Athens/Ben Epps, runway 27, 6,122 × 100 ft, asphalt - Equipment: Auto-pilot, Satellite tracking device, Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 69; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; last flight review June 2, 2018; seat: left; restraint: 3-point; flight hours: 1,340 total, 113.8 in this make and model, 1,248.4 as pilot in command, 3.4 in the last 90 days, 1 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: variable at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 81 °F, dew point 64 °F - Altimeter: 29.86 inHg - Observed at: AHN ## 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 20200503005449A](https://openairdocs.org/incident/20200503005449A), May 3, 2020: Mooney Aircraft Corp. M20K, Athens, GA, Substantial damage. On may 3, 2020 at approximately 11:00EST N231DW s/n 25-0144, a 1979 Mooney M20K was conducting a VFR flight from peachtree-dekalb airport (kpdk) to Athens, GA… ## Docket (5 files) The files NTSB released with the investigation on June 26, 2020, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=101243. 11.1 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 4.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40484883&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Master.PDF - Memorandum of Record FAA Correspondence (item 2, .PDF, 108 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40484884&FileExtension=.PDF&FileName=Memorandum%20of%20Record%20FAA%20Correspondence-Master.PDF - Memorandum of Record Mechanic Statement (item 3, .PDF, 110 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40484885&FileExtension=.PDF&FileName=Memorandum%20of%20Record%20Mechanic%20Statement-Master.PDF - Maintenance Records (item 4, .PDF, 6.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40484886&FileExtension=.PDF&FileName=Maintenance%20Records-Master.PDF - Photo Array (item 5, .PDF, 643 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40484887&FileExtension=.PDF&FileName=Photo%20Array-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.