# NTSB CEN21LA218: Cessna R182, N8051B, Tulsa, OK, May 13, 2021 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: May 13, 2021, 01:45 local (06:45 UTC) - Place: Tulsa, OK · Runway 36L at TUL. - Coordinates: 36.191374, -95.900161 - Nearby events: https://openairdocs.org/map.md?lat=36.1914&lon=-95.9002&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 4 - Basic report with no Prelim publish - NTSB office: Central Region - Parties: FAA Will Rogers FSDO - NTSB case key (mKey): 103081 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN21LA218 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/103081/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=103081 - Page: https://openairdocs.org/ntsb/CEN21LA218 ## Probable cause The pilot’s inability to extend the main landing gear due to incomplete maintenance, which resulted in a partial wheels-up landing and the mechanic’s failure to follow proper maintenance procedures that led to the loss of main landing gear system hydraulic pressure and the subsequent failure of the main landing gear to fully extend. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Attention/monitoring: attention](https://openairdocs.org/ntsb-findings/02021510): Personnel issues › Psychological · Maintenance personnel (probable cause); cases with it: [Cessna R182, 2 cases](https://openairdocs.org/ntsb-findings/02021510/cases.md?model=2072734), [All aircraft, 226 cases](https://openairdocs.org/ntsb-findings/02021510/cases.md) - [Maintenance: scheduled/routine maintenance](https://openairdocs.org/ntsb-findings/02062010): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Cessna R182, 2 cases](https://openairdocs.org/ntsb-findings/02062010/cases.md?model=2072734), [All aircraft, 320 cases](https://openairdocs.org/ntsb-findings/02062010/cases.md) - [Landing gear system: main landing gear](https://openairdocs.org/ntsb-findings/01023210): Aircraft › Aircraft systems · Failure (probable cause); cases with it: [Cessna R182, 4 cases](https://openairdocs.org/ntsb-findings/01023210/cases.md?model=2072734), [All aircraft, 241 cases](https://openairdocs.org/ntsb-findings/01023210/cases.md) - [Landing gear system: main landing gear](https://openairdocs.org/ntsb-findings/01023210): Aircraft › Aircraft systems · Incorrect service/maintenance (probable cause); cases with it: [Cessna R182, 4 cases](https://openairdocs.org/ntsb-findings/01023210/cases.md?model=2072734), [All aircraft, 241 cases](https://openairdocs.org/ntsb-findings/01023210/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Prior to flight: Aircraft maintenance event](https://openairdocs.org/ntsb-events/040); cases with it: [Cessna R182, 2 cases](https://openairdocs.org/ntsb-events/040/sequence.md?model=2072734), [All aircraft, 484 cases](https://openairdocs.org/ntsb-events/040/sequence.md) - [Landing: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [Cessna R182, 4 cases](https://openairdocs.org/ntsb-events/330/sequence.md?model=2072734), [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 R182, 15 cases](https://openairdocs.org/ntsb-events/095/sequence.md?model=2072734), [All aircraft, 584 cases](https://openairdocs.org/ntsb-events/095/sequence.md) - [Landing: Attempted remediation/recovery](https://openairdocs.org/ntsb-events/060); cases with it: [Cessna R182, 3 cases](https://openairdocs.org/ntsb-events/060/sequence.md?model=2072734), [All aircraft, 1,422 cases](https://openairdocs.org/ntsb-events/060/sequence.md) - [Landing: Off-field or emergency landing](https://openairdocs.org/ntsb-events/440); cases with it: [Cessna R182, 5 cases](https://openairdocs.org/ntsb-events/440/sequence.md?model=2072734), [All aircraft, 3,365 cases](https://openairdocs.org/ntsb-events/440/sequence.md) - [Landing: Abnormal runway contact](https://openairdocs.org/ntsb-events/090); cases with it: [Cessna R182, 9 cases](https://openairdocs.org/ntsb-events/090/sequence.md?model=2072734), [All aircraft, 1,506 cases](https://openairdocs.org/ntsb-events/090/sequence.md) ## Analysis The pilot reported that during a post-maintenance check flight, when he went to retract the landing gear after takeoff, he noticed that the amber light that indicated the gear was fully retracted, did not illuminate. The pilot verified the main landing gear indicator lights functioned and decided to validate in flight that the landing gear would extend. When he extended the landing gear, the green light that indicated the landing gear was down and locked did not illuminate, and the pilot was not able to visually confirm the extension of the main landing gear. After troubleshooting the system and several unsuccessful attempts to extend the main landing gear, the pilot performed a gear-up landing to the dry asphalt runway, with only the nose wheel extended. The airplane slid 500 ft before coming to a stop. The airplane sustained substantial damage to the right horizonal stabilizer and elevator. A postaccident examination of the airplane revealed that a b-nut on the main landing gear actuator gear down hydraulic line was only hand tightened, with visible stripped thread present. The mechanic who performed the annual inspection on the airplane, which included work on the main landing gear system, reported that he forgot to fully tighten the b-nut during the recent maintenance work, which resulted in a loss of main landing gear system hydraulic pressure in flight, and the pilot’s inability to fully extend the main landing gear. A successful main landing gear swing was performed during the maintenance work, but it was not performed after all the maintenance work was completed. Had the main landing gear swing been conducted after the maintenance work was completed, it is likely the loss of the main landing gear system hydraulic pressure would have been identified before the flight. ## Aircraft - Registration: [N8051B](https://openairdocs.org/aircraft/N8051B), registered now, S/N R18201574, built 1980 (OpenAirDocs) - Reported make and model: CESSNA R182 (NO SERIES) - Registry model: [Cessna R182](https://openairdocs.org/model/cessna-r182) (registry code 2072734) (OpenAirDocs) - Registry engine: [Lycoming 0-540 series](https://openairdocs.org/engine/lycoming-0-540-series) (registry code 41532, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: R18201574 - Year built: 1980 - Airframe hours: 4384.6 - Engines: Lycoming Engines O-540-J3C5D 235 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 11, 2021 - Departed: GCM, Claremore, OK - Destination: Same as departure - Airport: TUL, Tulsa Intl, runway 18R/36L, 6,101 × 150 ft, asphalt - Equipment: Electronic multifunction display, Electronic primary flight display, Stall warning system, ADS-B, Auto-pilot, Data recorder, Electronic flight bag or handheld device ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 55; injuries: none; commercial; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 2, without waivers/limitations; last flight review July 5, 2020; seat: left; restraint: 4-point; flight hours: 1,512 total, 1,222 in this make and model, 1,475 as pilot in command, 49 in the last 90 days, 11 in the last 30 days ## Weather - Conditions: Visual (VMC), Night - Wind: 320° at 4 knots - Visibility: 10 statute miles - Temperature: 50 °F, dew point 45 °F - Altimeter: 30.35 inHg - Observed at: KTUL, 1 nm away - METAR: KTUL 130553Z 32004KT 10SM FEW060 10/07 A3035 RMK AO2 SLP274 T01000072 10189 20100 402060100 51005 ## 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 20210513009339A](https://openairdocs.org/incident/20210513009339A), May 13, 2021: Cessna R182, Tulsa, OK, Substantial damage. The pilot stated that at 0930 CDT the evening of the event he went on a post annual inspection maintenance flight. The aircraft departed claremore, OK. (Kgcm)… ## Docket (3 files) The files NTSB released with the investigation on September 15, 2021, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=103081. 7.0 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 1.7 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12365310&FileExtension=pdf&FileName=NTSB%20Form%206120_1%20Redacted-Rel.pdf - Accident photographs (item 2, PDF, 5 pages, 1.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12364723&FileExtension=pdf&FileName=Accident%20Photographs-Rel.pdf - Additional documents (item 3, PDF, 34 pages, 3.9 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=12430632&FileExtension=pdf&FileName=Additional%20Documents%20Redacted-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.