# NTSB ERA15LA160: Cessna 172C, N8452X, Williamson, GA, March 15, 2015 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Limited investigation · Final report - Date: March 15, 2015, 11:34 local (15:34 UTC) - Place: Williamson, GA - Coordinates: 33, -84 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=33.0000&lon=-84.0000&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing-flare/touchdown: Landing gear collapse](https://openairdocs.org/ntsb-events/094) - Highest injury: Minor injuries - Injuries: 1 minor, 1 uninjured - Status: Completed, report October 21, 2015 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA - NTSB case key (mKey): 90891 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA15LA160 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/90891/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=90891 - Page: https://openairdocs.org/ntsb/ERA15LA160 ## Probable cause The separation of the nosewheel upon landing due to a missing bolt that attached the upper torque assembly to the nosewheel steering arm assembly. When and how the bolt separated could not be determined. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: nose/tail landing gear](https://openairdocs.org/ntsb-findings/01023220): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [Cessna 172C, 1 case](https://openairdocs.org/ntsb-findings/01023220/cases.md?model=2072408), [All aircraft, 185 cases](https://openairdocs.org/ntsb-findings/01023220/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing-flare/touchdown: Landing gear collapse](https://openairdocs.org/ntsb-events/094) (defining event); cases with it: [Cessna 172C, 3 cases](https://openairdocs.org/ntsb-events/094/sequence.md?model=2072408), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md) ## Analysis The pilot made a soft-field landing to a grass runway, and the initial touchdown was on the main wheels with the airplane in a nose-up attitude. As the airplane decelerated, the pilot lowered the nosewheel and felt a "significant" shimmy after it touched down. The pilot thought the shimmy damper had failed, so he applied back pressure on the control wheel to minimize weight on the nosewheel. As the airplane continued to decelerate, the pilot again lowered the nose, and a more substantial vibration occurred. He then raised the nosewheel as much as possible. Eventually, so much groundspeed had depleted that he could no longer hold the airplane's nosewheel off the ground. When the nosewheel touched down again, it separated from the airplane. Examination of the airplane revealed that a bolt and associated washer and nut that attached the upper torque assembly to the nosewheel steering arm assembly was missing, and it was not located. The pilot said that he saw the bolt during his preflight inspection. It could not be determined when the bolt separated from the nosewheel. According to the airplane manufacturer, without that bolt, the lower shock strut assembly of the nosewheel would freely caster in the shock strut tube assembly, which would result in a significant shimmy, and the nosewheel steering control would be significantly reduced or nonexistent. Without the torque assembly attached, the shimmy dampener would have limited-to-no effect. A review of the airplane maintenance logbooks revealed that no recent maintenance had been conducted on the nosewheel. The fracture surfaces of the broken nosewheel assembly were consistent with having failed due to overload forces during landing, and no preimpact anomalies were noted. It could not be determined how the bolt separated from the nosewheel steering arm assembly. ## Factual narrative On March 15, 2015, at 1134 eastern daylight time, N8452X, a Cessna 172C, sustained substantial damage during landing roll-out at the Peach State Airport (GA2), Williamson, Georgia. The airline transport rated pilot sustained minor injuries and the passenger was not injured. The airplane was registered to and operated by the R A Marsh Flying Club, Williamson, Georgia. No flight plan was filed for the local flight that departed about 1020. Visual meteorological conditions prevailed for the personal flight conducted under 14 Code of Federal Regulations Part 91. In a written statement, the pilot stated that he was making his first landing in the airplane, which was a soft field landing to a grass runway. The initial touchdown was on the main wheels with a nose up attitude. As the airplane decelerated, the pilot lowered the nose wheel. He said that immediately after the nose wheel touched down a "significant" nose shimmy was felt. The pilot thought the shimmy damper had failed, so he applied back pressure on the control wheel to minimize weight on the nose wheel. As the airplane continued to decelerate, the pilot again lowered the nose and a more substantial vibration occurred and he again raised the nose wheel as much as possible. Eventually, so much groundspeed had depleted that he could no longer hold the nose off the ground. When the nose wheel touched down on the ground for the last time, it completely failed and separated. The nose of the airplane then dropped to the ground and the airplane slid to a stop. A postaccident examination of the airplane was conducted by several Federal Aviation Administration (FAA) safety inspectors. According to one of the inspectors, the nose gear separated from the airplane and was fractured in several pieces. The firewall was wrinkled and the propeller was damaged. Examination of the nose gear revealed that an AN4-31 bolt and associated washer and nut that attached the upper torque assembly to the nose gear steering arm assembly was missing. The pilot said that he saw the bolt during his preflight inspection. The inspectors walked the grass runway in search of the bolt to see if it came out during takeoff or landing, but the bolt was not located. A review of photographs of the broken nose gear's fractured surfaces revealed the nose gear appeared to have separated from overload forces. According to a representative of the aircraft manufacturer, without this AN4-31 bolt, the lower shock assembly of the nose gear would freely caster in the shock strut tube assembly, which would result in a significant shimmy. In addition, nose-wheel steering control would also be significantly reduced or nonexistent. Without the torque assembly, the shimmy dampener would also have limited to no effect. A review of the aircraft maintenance logbooks revealed no recent work had been done to the nose gear. The pilot held a commercial pilot certificate for airplane single-engine land and an airline transport pilot rating formulti-engine land, and instrument airplane. The pilot reported a total of 17,065 total flight hours; of which, 3,000 of those hours were in a Cessna 172. He reported the weather at the time of the accident as calm wind and clear skies. ## Aircraft - Registration: [N8452X](https://openairdocs.org/aircraft/N8452X), registered now, S/N 17248952, built 1961 (OpenAirDocs) - Reported make and model: CESSNA 172C - Registry model: [Cessna 172C](https://openairdocs.org/model/cessna-172c) (registry code 2072408) (OpenAirDocs) - Registry engine: [Continental 0-300 series](https://openairdocs.org/engine/continental-0-300-series) (registry code 17022, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 17248952 - Year built: 1961 - Airframe hours: 2216.61 - Engines: CONT MOTOR O-300 SER 145 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: R A Marsh Flying Club LLC - Registered owner: R A Marsh Flying Club LLC - Airworthiness certificate: Standard, Normal - Last inspection: Annual, March 25, 2014 - Departed: GA2, Williamson, GA - Destination: GA2, Williamson, GA - Airport: GA2, Peach State Airport, runway 13, 2,400 × 100 ft, grass/turf ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 52; injuries: minor; commercial, airline transport, private; airplane ratings: multi-engine land, single-engine land; instrument ratings: airplane; medical: class 1, with waivers/limitations; last flight review August 5, 2014; seat: left; restraint: 4-point; flight hours: 17,065 total, 3,000 in this make and model, 5,000 as pilot in command, 240 in the last 90 days, 80 in the last 30 days, 8 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: calm - Visibility: 10 statute miles ## 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 20150315020259A](https://openairdocs.org/incident/20150315020259A), Mar 15, 2015: Cessna 172C, Williamson, GA, Substantial damage. On 15 March 2015, the pilot of a Cessna 172, registration number N8452X from Peach State Airport (GA2) for the purpose of a local VFR flight. With one… ## Docket (7 files) The files NTSB released with the investigation on September 24, 2015, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=90891. 5.6 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 593 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40432120&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Record of Conversation - FAA Inspector (item 2, .PDF, 69 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40432121&FileExtension=.PDF&FileName=Record%20of%20Conversation%20-%20FAA%20Inspector-Master.PDF - Email from Cessna (item 3, .PDF, 47 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40432122&FileExtension=.PDF&FileName=Email%20from%20Cessna-Redacted.PDF - Page 86 from Cessna 172 Illustrated Parts Catalog (item 4, .PDF, 242 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40432126&FileExtension=.PDF&FileName=Page%2086%20from%20Cessna%20172%20%20Illustrated%20Parts%20Catalog-Master.PDF - Photo 1 - Wreckage (Photo Courtesy of FAA) (item 5, .PDF, 1.5 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40432123&FileExtension=.PDF&FileName=Photo%201%20-%20Wreckage%20(Photo%20Courtesy%20of%20FAA)-Master.PDF - Photo 2 - Fractured Nose Gear Assembly (Photo Courtesy of FAA) (item 6, .PDF, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40432124&FileExtension=.PDF&FileName=Photo%202%20-%20Fractured%20Nose%20Gear%20Assembly%20(Photo%20Courtesy%20of%20FAA)-Master.PDF - Photo 3 - View of where missing bolt was supposed to be attached (Photo Courtesy of FAA) (item 7, .PDF, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40432125&FileExtension=.PDF&FileName=Photo%203%20-%20View%20of%20where%20missing%20bolt%20was%20supposed%20to%20be%20attached%20(Photo%20Courtesy%20of%20FAA)-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.