# NTSB CEN11CA640: Cessna T210M, N44HR, Cahokia, IL, August 25, 2011 - Type: NTSB accident investigation - Classification: Accident · No injuries · Data collection · Final report - Date: August 25, 2011, 17:31 local (22:31 UTC) - Place: Cahokia, IL - Coordinates: 38.570278, -90.154998 - Nearby events: https://openairdocs.org/map.md?lat=38.5703&lon=-90.1550&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 November 29, 2011 - Report: Approved by Office Director - NTSB office: Central Region - Parties: FAA - St Louis FSDO - NTSB case key (mKey): 81781 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN11CA640 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/81781/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=81781 - Page: https://openairdocs.org/ntsb/CEN11CA640 ## Probable cause A failure of a spring in the main landing gear actuation system that prevented the landing gear from extending. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: landing gear actuator](https://openairdocs.org/ntsb-findings/01023233): Aircraft › Aircraft systems · Malfunction (probable cause); cases with it: [Cessna T210M, 4 cases](https://openairdocs.org/ntsb-findings/01023233/cases.md?model=2073451), [All aircraft, 54 cases](https://openairdocs.org/ntsb-findings/01023233/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 T210M, 6 cases](https://openairdocs.org/ntsb-events/330/sequence.md?model=2073451), [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 T210M, 7 cases](https://openairdocs.org/ntsb-events/095/sequence.md?model=2073451), [All aircraft, 584 cases](https://openairdocs.org/ntsb-events/095/sequence.md) ## Analysis The pilot executed a wheel-up landing after normal and emergency extension procedures failed to properly lower the airplane's landing gear. The airplane sustained damage to the propeller, lower fuselage skins, and fuselage bulkheads. Postaccident retraction tests revealed that the landing gear extended and retracted abnormally. Examination of the landing gear system revealed a deformed spring on the uplock sequencing actuator. The spring was replaced and subsequent retraction tests were normal. Review of the hydraulic system for the airplane revealed that a failure of the uplock sequencing actuator could result in hydraulic pressure being directed to both sides of the main landing gear actuators, causing the landing gear to not fully extend. No other preexisting anomalies were found. ## Factual narrative The pilot executed a wheel-up landing after normal and emergency extension procedures failed to properly lower the airplane's landing gear. The airplane sustained damage to the propeller, lower fuselage skins, and fuselage bulkheads. Postaccident retraction tests revealed that the landing gear extended and retracted abnormally. Examination of the landing gear system revealed a deformed spring on the up lock sequencing actuator. The spring was replaced and subsequent retraction tests were normal. Review of the hydraulic system for the airplane revealed that a failure of the up lock sequencing actuator could result in hydraulic pressure being directed to both sides of the main landing gear actuators causing the landing gear to not fully extend. No other preexisting anomalies were found. ## Aircraft - Registration: [N44HR](https://openairdocs.org/aircraft/N44HR), registered now, S/N 21062685, built 1978 (OpenAirDocs) - Reported make and model: CESSNA T210M - Registry model: [Cessna T210M](https://openairdocs.org/model/cessna-t210m) (registry code 2073451) (OpenAirDocs) - Registry engine: [Continental TSIO-520 series](https://openairdocs.org/engine/continental-tsio-520-series) (registry code 17040, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 21062685 - Airframe hours: 5628 - Engines: CONT MOTOR TSIO-520-R 310 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Special, Restricted (Special); Standard, Normal - Last inspection: Annual, August 23, 2010 - Departed: CPS, Cahokia, IL - Destination: CPS, Cahokia, IL - Airport: CPS, St Louis Downtown Airport, runway 12L, 5,300 × 75 ft, concrete ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 44; injuries: none; airline transport, flight engineer, commercial, flight instructor; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 1, without waivers/limitations; last flight review December 22, 2010; seat: left; flight hours: 18,526 total, 140 in this make and model, 14,793 as pilot in command, 273 in the last 90 days, 116 in the last 30 days, 4 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 10° at 7 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 79 °F, dew point 55 °F - Altimeter: 30.01 inHg - Observed at: CPS ## 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 20110825020779A](https://openairdocs.org/incident/20110825020779A), Aug 25, 2011: Cessna T210M, Cahokia, IL, Substantial damage. Pilot departed St Louis Downtown Airport (kcps) for local flight to warm up aircraft engine prior to beginning annual inspection. Upon returning to land, found… ## Docket (3 files) The files NTSB released with the investigation on October 21, 2011, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=81781. 1.1 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 975 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40356168&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - FAA record of conversation with mechanic (item 2, .PDF, 44 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40356170&FileExtension=.PDF&FileName=FAA%20record%20of%20conversation%20with%20mechanic-Redacted.PDF - Examination report from mechanic (item 3, .PDF, 106 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40356173&FileExtension=.PDF&FileName=Examination%20report%20from%20mechanic-Redacted.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.