# NTSB ERA22LA319: Mooney M20J, N9158D, Charleston, SC, June 12, 2022 - Type: NTSB accident investigation - Classification: Accident · No injuries · Class 4 · Limited · Final report - Date: June 12, 2022, 01:48 local (05:48 UTC) - Place: Charleston, SC - Coordinates: 32.892001, -80.041811 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=32.8920&lon=-80.0418&mi=10 - Phase of flight: [Approach](https://openairdocs.org/ntsb-phases/500) (OpenAirDocs' grouping) - Defining event: [Approach-VFR pattern final: 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: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 105499 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA22LA319 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/105499/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=105499 - Page: https://openairdocs.org/ntsb/ERA22LA319 ## Probable cause The failure of the torsion spring inside the drive clutch assembly of the landing gear actuator which prevented normal and manual extension of the landing gear. ## 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 · Failure (probable cause); cases with it: [Mooney M20J, 1 case](https://openairdocs.org/ntsb-findings/01023233/cases.md?model=5870219), [All aircraft, 54 cases](https://openairdocs.org/ntsb-findings/01023233/cases.md) - [Use of equip/info: use of equip/system](https://openairdocs.org/ntsb-findings/02063015): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Mooney M20J, 7 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md?model=5870219), [All aircraft, 1,391 cases](https://openairdocs.org/ntsb-findings/02063015/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Approach-VFR pattern final: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [Mooney M20J, 2 cases](https://openairdocs.org/ntsb-events/330/sequence.md?model=5870219), [All aircraft, 994 cases](https://openairdocs.org/ntsb-events/330/sequence.md) - [Landing-flare/touchdown: Landing gear not configured](https://openairdocs.org/ntsb-events/095); cases with it: [Mooney M20J, 6 cases](https://openairdocs.org/ntsb-events/095/sequence.md?model=5870219), [All aircraft, 584 cases](https://openairdocs.org/ntsb-events/095/sequence.md) ## Analysis After arrival to the destination airport near the conclusion of a cross-country flight the private pilot reported the landing gear circuit breaker (CB) tripped after he attempted to lower the landing gear electrically via the normal method. He reset the CB and again attempted to lower the landing gear via the normal method, but the same CB tripped. He overflew the airport then flew towards the coast where he reviewed the airplane’s Pilot’s Operating Handbook and attempted multiple times to manually lower the landing gear but was unsuccessful. He also contacted his mechanic to obtain assistance, but he was unable to lower the landing gear. At the suggestion of his mechanic, he diverted to a larger nearby airport where he performed a go-around on the first approach because the flight was too fast, then returned and landed gear-up. According to maintenance personnel associated with recovery of the airplane, lowering the landing gear required them to disconnect the push/pull tubes near the landing gear actuator for each landing gear. Further, the emergency cable activation lever would not move and was “jammed….” Following removal of the push/pull tubes near the actuator the emergency cable activation lever would only travel about 90%. Following removal of the actuator from the airplane, manual operation revealed the actuator turned freely in the retracted direction but would not turn in the gear extension direction. Disassembly inspection of the clutch drive assembly of the landing gear actuator revealed one “tang” of the torsion spring associated with gear extension was fractured. By system design the emergency extension system did not bypass the clutch and damaged spring; thus, a single point failure (torsion spring) precluded manual and normal extension of the landing gear. According to airframe manufacturer, the landing gear actuator and fractured torsion spring are no longer available or supported, but they do have a retrofit for the landing gear actuator. An airframe manufacturer service instruction specified replacement of the torsion spring in the drive clutch assembly of the landing gear actuator was last performed nearly 5 years and 427 hours earlier. The service instruction, due every 1,000 hours, was due again in about 573 hours. The mechanic who performed the airplane’s last annual inspection nearly 8 months and 49 hours earlier reported that as part of that inspection he performed in part, normal and emergency extension checks of the landing gear and found no issues. He did not perform any maintenance to the landing gear except for lubrication. ## Aircraft - Registration: [N9158D](https://openairdocs.org/aircraft/N9158D), registered now, S/N 24-3261, built 1992 (OpenAirDocs) - Reported make and model: MOONEY M20J (NO SERIES EXISTS) - Registry model: [Mooney M20J](https://openairdocs.org/model/mooney-m20j) (registry code 5870219) (OpenAirDocs) - Registry engine: [Lycoming I0360 SER A&C](https://openairdocs.org/engine/lycoming-i0360-ser-a-c) (registry code 41511, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 24-3261 - Year built: 1992 - Airframe hours: 3416 - Engines: Lycoming IO-360-A3B6D 200 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, October 19, 2021, 49 hours before - Departed: MDW, Chicago, IL - Destination: LRO, Mount Pleasant, SC - Flight plan: IFR - Airport: CHS, Charleston Afb/Intl, runway 3, 7,000 × 150 ft, concrete - Equipment: Stall warning system, ADS-B, Auto-pilot ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 59; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3; last flight review February 21, 2021; seat: left; restraint: 3-point; flight hours: 1,804 total, 905 in this make and model, 1,722 as pilot in command, 26 in the last 90 days, 14 in the last 30 days, 5 in the last 24 hours ## Weather - Conditions: Visual (VMC), Not reported - Wind: 150° at 4 knots - Visibility: 10 statute miles - Lowest ceiling: none - Temperature: 75 °F, dew point 73 °F - Altimeter: 29.90 inHg - Observed at: KCHS, 0.22 nm away - METAR: METAR KCHS 120556Z 15004KT 10SM SCT120 24/23 A2990 RMK AO2 SLP125 T02440233 10267 20244 58009= ## 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 20220612010379A](https://openairdocs.org/incident/20220612010379A), Jun 12, 2022: Mooney M20J, Charleston, SC, Minor damage. On June 12 2022 at approximately 0150 a Mooney M20J sustained a gear up landing. The PIC departed mdw on a IFR flight plan to lro. Upon arrival the PIC… ## Docket (8 files) The files NTSB released with the investigation on October 24, 2022, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=105499. 15.7 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 11 pages, 9.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14252429&FileExtension=pdf&FileName=6120_1%20Master%20Form%20Fm%20Web%204%206%202022_Recd%208%201%202022_Redacted-Rel.pdf - Record of NTSB conversations (item 2, PDF, 3 pages, 124 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14593644&FileExtension=pdf&FileName=Record%20of%20NTSB%20Conversations_3%20Pages_Redacted-Rel.pdf - Excerpts from maintenance records (item 3, PDF, 1 page, 1.8 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14593432&FileExtension=pdf&FileName=2017%20Maintenance%20Record%20Entry_Redacted-Rel.pdf - Memorandum for record - additional actuator information (item 4, PDF, 1 page, 114 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14595212&FileExtension=pdf&FileName=Memorandum%20For%20Record%20Form%20-%20Addtnl%20Actuator%20Information-Rel.pdf - Memorandum for record - aircraft recovery and actuator disassembly information (item 5, PDF, 1 page, 111 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14593879&FileExtension=pdf&FileName=Memorandum%20For%20Record%20-%20Aircraft%20Recovery%20and%20Actuator%20Disassembly%20Information_Redacted-Rel.pdf - FAA inspector statement (item 6, PDF, 5 pages, 11 photos, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14602889&FileExtension=pdf&FileName=Inspector%20Field%20notes%20N9158D%20flatten-Rel.pdf - Investigative photographs (item 7, PDF, 6 pages, 6 photos, 2.0 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14593654&FileExtension=pdf&FileName=Investigative%20Photographs_6%20Pages-Rel.pdf - Release of aircraft wreckage, NTSB form 6120.15 (item 8, PDF, 1 page, 400 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=14595744&FileExtension=pdf&FileName=Fully%20Exctd%20Wrkge%20Release_Redacted-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.