# NTSB GAA15CA173: Cessna 182, N234CF, Athens, TN, July 6, 2015 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: July 6, 2015, 14:19 local (18:19 UTC) - Place: Athens, TN - Coordinates: 35.403888, -84.558891 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=35.4039&lon=-84.5589&mi=10 - Phase of flight: [Taxi](https://openairdocs.org/ntsb-phases/250) (OpenAirDocs' grouping) - Defining event: [Taxi: Miscellaneous/other](https://openairdocs.org/ntsb-events/900) - Highest injury: No injuries - Injuries: 4 uninjured - Status: Completed, report September 11, 2015 - Report: Approved by Office Director - NTSB office: General Aviation Accidents - Parties: Nashville FSDO (FAA) - NTSB case key (mKey): 91531 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=GAA15CA173 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/91531/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=91531 - Page: https://openairdocs.org/ntsb/GAA15CA173 ## Probable cause The failure of the taxiway surface due to a sink hole, which resulted in the right main landing gear sinking into terrain causing substantial damage to the fuselage. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Airport facilities/design: taxiway condition](https://openairdocs.org/ntsb-findings/03017045): Environmental issues › Operating environment · Effect on equipment (probable cause); cases with it: [Cessna 182T, 1 case](https://openairdocs.org/ntsb-findings/03017045/cases.md?model=2072703), [All aircraft, 4 cases](https://openairdocs.org/ntsb-findings/03017045/cases.md) - [Fuselage: fuselage main structure](https://openairdocs.org/ntsb-findings/01035310): Aircraft › Aircraft structures · Damaged/degraded; cases with it: [Cessna 182T, 1 case](https://openairdocs.org/ntsb-findings/01035310/cases.md?model=2072703), [All aircraft, 24 cases](https://openairdocs.org/ntsb-findings/01035310/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Taxi: Miscellaneous/other](https://openairdocs.org/ntsb-events/900) (defining event); cases with it: [Cessna 182T, 3 cases](https://openairdocs.org/ntsb-events/900/sequence.md?model=2072703), [All aircraft, 1,556 cases](https://openairdocs.org/ntsb-events/900/sequence.md) - [Taxi: Collision with terr/obj (non-CFIT) ](https://openairdocs.org/ntsb-events/470); cases with it: [Cessna 182T, 17 cases](https://openairdocs.org/ntsb-events/470/sequence.md?model=2072703), [All aircraft, 10,189 cases](https://openairdocs.org/ntsb-events/470/sequence.md) ## Analysis The pilot reported that while taxiing to the active runway, about 50 yards ahead, he saw what appeared to be a black oval, 4-5 feet in diameter on the taxiway. He stated that he believed it was a wet spot or an area of new pavement, and started to steer around it. As the pilot approached the spot, he reported that he glanced off to the left and saw sink holes in the field, then he looked back towards the taxiway and suddenly the airplane sank into the taxiway. The airplane came to a stop after the right wheel fell into the sink hole and the fuselage impacted the taxiway surface. The hole had opened up to about 9-10 feet across and 7-8 feet deep. The fuselage was substantially damaged in the accident. During a postaccident interview, the airport manager stated that she was unaware of sink holes on any safety areas at the airport, including this taxiway. After the accident, the airport immediately issued a notice to airmen closing the taxiway. The pilot stated there were no mechanical malfunctions or failures with the airplane that would have precluded normal operation. ## Factual narrative The pilot reported that while taxiing to the active runway, about 50 yards ahead, he saw what appeared to be a black oval, 4-5 feet in diameter on the taxiway. He stated that he believed it was a wet spot or an area of new pavement, and started to steer around it. As the pilot approached the spot, he reported that he glanced off to the left and saw sink holes in the field, then he looked back towards the taxiway and suddenly the airplane sank into the taxiway. The airplane came to a stop after the right wheel fell into the sink hole and the fuselage impacted the taxiway surface. The hole had opened up to about 9-10 feet across and 7-8 feet deep. The fuselage was substantially damaged in the accident. During a postaccident interview, the airport manager stated that she was unaware of sink holes on any safety areas at the airport, including this taxiway. After the accident, the airport immediately issued a notice to airmen closing the taxiway. The pilot stated there were no mechanical malfunctions or failures with the airplane that would have precluded normal operation. ## Aircraft - Registration: [N234CF](https://openairdocs.org/deregistered/N234CF-2019-03-25), registration cancelled 2019-03-25, S/N 18281076, built 2002 (OpenAirDocs) - Reported make and model: CESSNA 182 (T) - Registry model: [Cessna 182T](https://openairdocs.org/model/cessna-182t) (registry code 2072703) (OpenAirDocs) - Registry engine: [Lycoming IO-540 series](https://openairdocs.org/engine/lycoming-io-540-series) (registry code 41530, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 18281076 - Year built: 2002 - Airframe hours: 2923.8 - Engines: LYCOMING IO-540-AB1A5 235 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Crystal Air, Inc. - Registered owner: Collins Aviation LLC - Airworthiness certificate: Standard, Normal - Last inspection: 100 hour, June 17, 2015, 39 hours before - Departed: MMI, Athens, TN - Destination: MMI, Athens, TN - Airport: MMI, Mcminn County - Equipment: Auto-pilot, Electronic multifunction display ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 59; injuries: none; private; airplane ratings: single-engine land; medical: class 3, with waivers/limitations; last flight review October 13, 2014; seat: left; restraint: 3-point; flight hours: 110 total, 20.2 in this make and model, 60 as pilot in command, 11 in the last 90 days, 2 in the last 30 days, 0 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 230° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: 4,900 ft broken - Temperature: 84 °F, dew point 66 °F - Altimeter: 30.15 inHg - Observed at: KRZR, 16 nm away ## 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 20150706009649A](https://openairdocs.org/incident/20150706009649A), Jul 6, 2015: Cessna 182T, Athens, TN, Substantial damage. Aircraft was taxing out for departure when the taxiway opened up into a sink hole. The right main gear fell into the hole but the momentum carried the aircraft… ## Docket (4 files) The files NTSB released with the investigation on August 12, 2015, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=91531. 844 KB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 632 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40430700&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Record of Conversation (Pilot in Command) (item 2, .PDF, 68 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40430701&FileExtension=.PDF&FileName=Record%20of%20Conversation%20(Pilot%20in%20Command)-Master.PDF - Record of Conversation (Airport Manager) (item 3, .PDF, 69 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40430702&FileExtension=.PDF&FileName=Record%20of%20Conversation%20(Airport%20Manager)-Master.PDF - Photo 1 – Airplane and Sinkhole (Courtesy of Operator) (item 4, .PDF, 74 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40430703&FileExtension=.PDF&FileName=Photo%201%20%E2%80%93%20Airplane%20and%20Sinkhole%20(Courtesy%20of%20Operator)-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.