# NTSB ERA25LA317: Cessna 170B, N4584C, Knoxville, TN, August 25, 2025 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: August 25, 2025, 17:50 local (21:50 UTC) - Place: Knoxville, TN · Field - Coordinates: 36, -84 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=36.0000&lon=-84.0000&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 November 20, 2025 - 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): 200865 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA25LA317 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/200865/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=200865 - Page: https://openairdocs.org/ntsb/ERA25LA317 ## Probable cause The pilot’s failure to maintain directional control during landing roll in a crosswind, which resulted in a runway excursion and a subsequent ground loop. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Cessna 170B, 91 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=2072306), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) - [Performance/control parameters: directional control](https://openairdocs.org/ntsb-findings/01062020): Aircraft › Aircraft oper/perf/capability · Not attained/maintained (probable cause); cases with it: [Cessna 170B, 74 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md?model=2072306), [All aircraft, 3,958 cases](https://openairdocs.org/ntsb-findings/01062020/cases.md) - [Wind: crosswind](https://openairdocs.org/ntsb-findings/03034040): Environmental issues › Conditions/weather/phenomena · Response/compensation (probable cause); cases with it: [Cessna 170B, 13 cases](https://openairdocs.org/ntsb-findings/03034040/cases.md?model=2072306), [All aircraft, 1,008 cases](https://openairdocs.org/ntsb-findings/03034040/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: [Cessna 170B, 84 cases](https://openairdocs.org/ntsb-events/230/sequence.md?model=2072306), [All aircraft, 4,585 cases](https://openairdocs.org/ntsb-events/230/sequence.md) - [Landing-landing roll: Runway excursion](https://openairdocs.org/ntsb-events/300); cases with it: [Cessna 170B, 37 cases](https://openairdocs.org/ntsb-events/300/sequence.md?model=2072306), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) ## Analysis The pilot of the tailwheel-equipped airplane approached the destination airport, and while in the traffic pattern there, the airplane encountered a crosswind. During the base-to-final turn, he was dissatisfied with the airplane’s altitude and performed a go-around. On the subsequent approach, he used rudder inputs to maintain alignment with the runway centerline. After touchdown, the airplane drifted right, and as it decelerated, he applied right rudder but was unable to maintain directional control. The airplane veered off the left side of the runway and ground-looped, coming to rest on the adjacent terrain. The airplane sustained substantial damage to the right wingtip and aileron. The pilot reported that there were no preaccident mechanical malfunctions or failures of the airplane that would have precluded normal operation. ## Aircraft - Registration: [N4584C](https://openairdocs.org/aircraft/N4584C), registered now, S/N 25528, built 1953 (OpenAirDocs) - Reported make and model: CESSNA 170B - Registry model: [Cessna 170B](https://openairdocs.org/model/cessna-170b) (registry code 2072306) (OpenAirDocs) - Registry engine: [Continental 0-300-A](https://openairdocs.org/engine/continental-0-300-a) (registry code 17173, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 25528 - Year built: 1953 - Engines: Continental O-300 145 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 2, 2025, 9 hours before - Departed: 4O1, Waynesville, OH - Destination: EKQ, Monticello, KY - Airport: EKQ, Wayne County, runway 03, 4,000 × 75 ft, asphalt - Equipment: Stall warning system ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 61; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, with waivers/limitations; last flight review August 23, 2023; seat: left; restraint: 4-point; flight hours: 729 total, 32 in this make and model, 595 as pilot in command, 7 in the last 90 days, 7 in the last 30 days ## Weather - Conditions: Visual (VMC), Day - Wind: 300° at 9 knots - Visibility: 10 statute miles - Temperature: 73 °F, dew point 52 °F - Altimeter: 30.10 inHg - Observed at: EKQ, 12 nm away - METAR: METAR KEKQ 252156Z AUTO 30009KT 10SM SCT060 23/11 A3010 RMK AO2 SLP187 T02330106 PNO $= ## 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 20250825014769A](https://openairdocs.org/incident/20250825014769A), Aug 25, 2025: Cessna 170B, Monticello, KY, Substantial damage. During landing touchdown and rollout the aircraft veered to the left and departed the runway surface. The right wing, right aileron, nose cowling, and… ## Docket (4 files) The files NTSB released with the investigation on November 20, 2025, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=200865. 2.3 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 10 pages, 1.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19503437&FileExtension=pdf&FileName=6120%20LA317_Redacted-Rel.pdf - Memorandum for record - FAA inspector's statement (item 2, PDF, 1 page, 62 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19507708&FileExtension=pdf&FileName=MOR%20FAA%20LA317-Rel.pdf - Crosswind calculation (item 3, PDF, 1 page, 67 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19504416&FileExtension=pdf&FileName=Crosswind%20Calculation%20LA317-Rel.pdf - Investigation photos (item 4, PDF, 4 pages, 725 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=19507216&FileExtension=pdf&FileName=Investigative%20Photos%20LA317-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.