# NTSB CEN22LA378: Cessna 210B, N9637X, Clinton, AR, August 9, 2022 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 3 · Limited · Final report - Date: August 9, 2022, 10:57 local (15:57 UTC) - Place: Clinton, AR - Coordinates: 35.597039, -92.448352 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=35.5970&lon=-92.4484&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 3 - NTSB office: Central Region - Parties: FAA - NTSB case key (mKey): 105706 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN22LA378 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/105706/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=105706 - Page: https://openairdocs.org/ntsb/CEN22LA378 ## Probable cause A fatigue crack in the hydraulic actuator, which resulted in the loss of hydraulic fluid and the pilot’s inability to fully extend the landing gear. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Hydraulic power system: accumulator, main](https://openairdocs.org/ntsb-findings/01022911): Aircraft › Aircraft systems · Fatigue/wear/corrosion (probable cause); cases with it: [Cessna 210B, 1 case](https://openairdocs.org/ntsb-findings/01022911/cases.md?model=2073410), [All aircraft, 3 cases](https://openairdocs.org/ntsb-findings/01022911/cases.md) - [Hydraulic power system: accumulator, main](https://openairdocs.org/ntsb-findings/01022911): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [Cessna 210B, 1 case](https://openairdocs.org/ntsb-findings/01022911/cases.md?model=2073410), [All aircraft, 3 cases](https://openairdocs.org/ntsb-findings/01022911/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [Cessna 210B, 5 cases](https://openairdocs.org/ntsb-events/330/sequence.md?model=2073410), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Landing: Landing gear not configured](https://openairdocs.org/ntsb-events/095); cases with it: [Cessna 210B, 3 cases](https://openairdocs.org/ntsb-events/095/sequence.md?model=2073410), [All aircraft, 584 cases](https://openairdocs.org/ntsb-events/095/sequence.md) - [Landing: Landing gear collapse](https://openairdocs.org/ntsb-events/094); cases with it: [Cessna 210B, 4 cases](https://openairdocs.org/ntsb-events/094/sequence.md?model=2073410), [All aircraft, 1,787 cases](https://openairdocs.org/ntsb-events/094/sequence.md) ## Analysis The pilot reported that the landing gear retracted normally on takeoff; however, when he attempted to extend the landing gear in preparation for landing, the nosewheel extended and locked into place but the main landing gear did not fully extend. The pilot completed the checklist items for “landing gear emergency operation,” but the landing gear still did not fully extend and lock into place. Unable to extend the main landing gear, the pilot elected to accomplish the landing with the nosewheel extended and the main gear out of the wheel well, but not in the down-and-locked position. The pilot shut down the engine when the landing was assured to protect the engine. After the touchdown and during deceleration, the airplane rolled slightly to the left and the left elevator and horizontal stabilizer contacted the runway, which resulted in substantial damage. Postaccident examination of the hydraulic actuator revealed a fatigue crack that initiated along the retaining ring groove of the actuator. The crack propagated in a circumferential direction outward and once the fatigue crack grew to its terminal size, the remainder of the cross-section fractured from mixed overstress and fatigue. This led to part of the housing barrel fracturing in overstress, allowing the release of the internal pressurized hydraulic fluid. ## Factual narrative On August 9, 2022, about 1057 central daylight time, a Cessna 210B airplane, N9637X, sustained substantial damage when it was involved in an accident near Clinton, Arkansas. The pilot was uninjured. The airplane was being operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that the landing gear retracted normally during takeoff; however, when he attempted to extend the landing gear in preparation for the landing, the nosewheel extended and locked into place but the main landing gear did not fully extend. The pilot completed the checklist items for “landing gear emergency operation,” but the landing gear still did not fully extend and lock into place. Unable to extend the main landing gear, the pilot elected to accomplish the landing with the nosewheel extended and the main landing gear in the trail position. The pilot shut down the engine when the landing was assured to protect the engine. After the touchdown and during deceleration, the airplane rolled slightly to the left and the left elevator and horizontal stabilizer contacted the runway, which resulted in substantial damage to both structures. Postaccident examination revealed a fracture of the hydraulic actuator which allowed the hydraulic fluid to escape the system. After removal, the hydraulic actuator was sent to the National Transportation Safety Board Materials Laboratory for a detailed fracture analysis. The barrel of the housing was sectioned to separate the cracked area from the rest of the assembly. The examination of the fracture surfaces revealed features consistent with fatigue cracking having initiated along the retaining ring groove of the actuator, propagating outward in a circumferential direction. Once the fatigue crack grew to its terminal size, the remainder of the cross-section fractured from mixed overstress and fatigue. This cracking led to part of the housing barrel fracturing in overstress, allowing the release of the internal pressurized hydraulic fluid. Maintenance records for the airplane show that overhauled main landing gear actuators were installed on June 10, 2021, about 14 months and 179 hours of airframe total time before the accident occurred. ## Aircraft - Registration: [N9637X](https://openairdocs.org/aircraft/N9637X), registered now, S/N 21057937, built 1962 (OpenAirDocs) - Reported make and model: CESSNA 210B - Registry model: [Cessna 210B](https://openairdocs.org/model/cessna-210b) (registry code 2073410) (OpenAirDocs) - Registry engine: [Continental I0-470 series](https://openairdocs.org/engine/continental-i0-470-series) (registry code 17027, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 21057937 - Year built: 1962 - Airframe hours: 6767 - Engines: Continental IO-470-ECS 260 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Acp Enterprises LLC - Registered owner: Acp Enterprises LLC - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 31, 2022 - Departed: 2M8, Millington, TN - Destination: Same as departure - Airport: CCA, Clinton Muni, runway 31, 4,007 × 60 ft, asphalt - Equipment: Electronic multifunction display, Electronic flight bag or handheld device, Auto-pilot, ADS-B, Onboard weather, Electronic primary flight display ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 51; injuries: none; commercial; airplane ratings: single-engine sea, single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review April 14, 2022; seat: left; restraint: lap only; flight hours: 5,653 total, 3,891 in this make and model, 5,521 as pilot in command, 31 in the last 90 days, 6 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 310° at 5 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 79 °F, dew point 73 °F - Altimeter: 30.10 inHg - Observed at: KCCA - METAR: KCCA 091535Z AUTO 31005KT 10SM CLR 26/23 A3010 RMK AO2 ## 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 20220809014329A](https://openairdocs.org/incident/20220809014329A), Aug 9, 2022: Cessna 210B, Clinton, AR, Substantial damage. On 2022.08.09 at approximately 1100 CST, [privacy data omitted], a Cessna C210B aircraft flown by a commercial pilot, with 5,653 hours flight time, was on VFR… ## Other investigations on N9637X (2) 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. - [NTSB FTW93LA036](https://openairdocs.org/ntsb/FTW93LA036), Nov 8, 1992: Cessna 210B (N9637X), Mountain View, AR, substantial damage. Probable cause: THE COLLAPSED RIGHT MAIN GEAR DUE TO THE GEAR LOCKING MECHANISM NOT BEING ENGAGED. A FACTOR WAS THE FAILED CRANKSHAFT. - [NTSB UNK64X1239](https://openairdocs.org/ntsb/UNK64X1239), Apr 9, 1964: Cessna 210B (N9637X), Kimberling, MO, substantial damage ## Docket (5 files) The files NTSB released with the investigation on September 27, 2023, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=105706. 11.0 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 1.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15330516&FileExtension=pdf&FileName=6120_Redacted-Rel.pdf - Maintenance records (item 2, PDF, 1 page, 2.4 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15330587&FileExtension=pdf&FileName=Logbook%20Entry_Redacted-Rel.pdf - Materials laboratory factual report (item 3, PDF, 20 pages, 24 photos, 4.1 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15257569&FileExtension=pdf&FileName=23-016%20-%20Materials%20Lab%20Factual%20Report%20(CEN22LA378)-Rel.pdf - Release of aircraft wreckage, NTSB form 6120.15 (item 4, PDF, 4 pages, 2.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15329770&FileExtension=pdf&FileName=Wreckage%20Release_Redacted-Rel.pdf - Photos (item 5, PDF, 2 pages, 270 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=15332677&FileExtension=pdf&FileName=Photo%20Array-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.