# NTSB ERA13LA175: Mooney M20F, N9387V, Leesburg, FL, March 16, 2013 - Type: NTSB accident investigation - Classification: Accident · No injuries · Limited investigation · Final report - Date: March 16, 2013, 11:30 local (15:30 UTC) - Place: Leesburg, FL - Coordinates: 28.822778, -81.808609 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=28.8228&lon=-81.8086&mi=10 - Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping) - Defining event: [Maneuvering: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) - Highest injury: No injuries - Injuries: 1 uninjured - Status: Completed, report August 29, 2013 - Report: Approved by Office Director - NTSB office: Eastern Region Aviation - Parties: FAA/FSDO - NTSB case key (mKey): 86465 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=ERA13LA175 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/86465/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=86465 - Page: https://openairdocs.org/ntsb/ERA13LA175 ## Probable cause The incorrect rigging of the landing gear emergency extension system by unknown maintenance personnel, which resulted in a failure of the emergency extension cable, and jamming of the normal extension gear motor. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: gear extension and retract sys](https://openairdocs.org/ntsb-findings/01023230): Aircraft › Aircraft systems · Incorrect service/maintenance (probable cause); cases with it: [Mooney M20F, 3 cases](https://openairdocs.org/ntsb-findings/01023230/cases.md?model=5870214), [All aircraft, 416 cases](https://openairdocs.org/ntsb-findings/01023230/cases.md) - [Maintenance](https://openairdocs.org/ntsb-findings/02062000): Personnel issues › Task performance · Maintenance personnel (probable cause); cases with it: [Mooney M20F, 1 case](https://openairdocs.org/ntsb-findings/02062000/cases.md?model=5870214), [All aircraft, 143 cases](https://openairdocs.org/ntsb-findings/02062000/cases.md) - [Landing gear system: gear extension and retract sys](https://openairdocs.org/ntsb-findings/01023230): Aircraft › Aircraft systems · Malfunction; cases with it: [Mooney M20F, 3 cases](https://openairdocs.org/ntsb-findings/01023230/cases.md?model=5870214), [All aircraft, 416 cases](https://openairdocs.org/ntsb-findings/01023230/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: [Mooney M20F, 1 case](https://openairdocs.org/ntsb-events/040/sequence.md?model=5870214), [All aircraft, 484 cases](https://openairdocs.org/ntsb-events/040/sequence.md) - [Maneuvering: Sys/Comp malf/fail (non-power)](https://openairdocs.org/ntsb-events/330) (defining event); cases with it: [Mooney M20F, 1 case](https://openairdocs.org/ntsb-events/330/sequence.md?model=5870214), [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: [Mooney M20F, 2 cases](https://openairdocs.org/ntsb-events/095/sequence.md?model=5870214), [All aircraft, 584 cases](https://openairdocs.org/ntsb-events/095/sequence.md) ## Analysis The pilot reported that when he attempted to extend the landing gear, he heard a "snap," and the landing gear did not extend. He then cycled the landing gear and attempted the emergency (manual) landing gear extension procedure with no success. The pilot subsequently performed a gear-up landing to a grassy area at an airport. Examination of the airplane revealed that the emergency gear extension cable terminated with a spline drive at the landing gear actuator. The emergency cable was separated from the spline drive, which was seized. The emergency gear extension cable was also misrigged, which allowed it to contact the landing gear actuator arm and engage the cable during normal gear operations. Subsequently, with a seized spline engaged to the electric landing gear motor via the actuator, during normal gear operations, the electric landing gear motor would not be able to overcome the seized spline to actuate the landing gear. The airplane had been operated about 60 hours since its most recent annual inspection, which was completed about 10 months before the accident. Review of the airplane's most recent airframe logbook (dating back 7 years) revealed that the landing gear actuator was removed and replaced about 4 years before the accident. During reinstallation of the actuator, an emergency (manual) gear extension was successfully completed. There were no other entries pertaining to emergency (manual) gear extension in the airframe logbook; however, the entry for the most recent 100 hour inspection noted three landing gear retraction cycles. The mechanic that recorded that entry stated it was a standard entry and typically more than three cycles are completed with the first one being the emergency (manual) extension. While it was likely that a mechanic checked the rigging of the emergency gear extension cable following the actuator replacement, the investigation was unable to determine if the rigging of the emergency gear extension cable was affected by any subsequent maintenance. Additionally, the cable routing and rigging wouldn't typically be inspected if the landing gear manual extension was successfully accomplished during the 100-hour or annual inspections. ## Factual narrative On March 16, 2013, about 1130 eastern daylight time, a Mooney M20F, N9387V, operated by a private individual, was substantially damaged during a gear-up landing at Leesburg International Airport (LEE), Leesburg, Florida. The commercial pilot was not injured. The personal flight was conducted under the provisions of 14 Code of Federal Regulations Part 91. Visual meteorological conditions prevailed and no flight plan was filed for the local flight that departed LEE about 1030. The pilot reported that while practicing slow-flight, he attempted to extend the flaps and landing gear. The flaps extended, but he heard a "snap" and the landing gear did not extend. Additionally, there was no cockpit indication of the landing gear being retracted or extended. Utilizing the pilot operating handbook, he cycled the landing gear with no success. He then attempted the emergency (manual) landing gear extension procedure, also with no success. The pilot subsequently performed a low pass and LEE control tower personnel confirmed that the landing gear was not extended. The pilot then performed a gear-up landing on a grassy area at LEE. The airplane came to rest upright; however, the empennage sustained substantial damage. The airplane was examined by a mechanic, under the supervision of a Federal Aviation Administration inspector. The mechanic stated that the emergency (manual) gear extension cable terminated with a spline drive at the landing gear actuator. He observed that the emergency gear extension cable spline drive was seized and the cable portion behind it rotated freely in its sheath. The mechanic added that at some point in the airplane's history, the emergency gear cable separated from its terminating spline drive. This would not normally affect the landing gear system unless the emergency landing gear extension cable was engaged from the cockpit via a knob. However, the mechanic also noted that the emergency gear extension cable was previously mis-rigged, which allowed it to contact the actuator arm and engage the cable during normal gear operations. Subsequently, with a seized spline engaged to the electric landing gear motor via the actuator, during normal gear operations, the electric landing gear motor would not be able to overcome the seized spline to actuate the landing gear. Review of the airplane's most recent airframe logbook revealed entries dating back to May 2006. Further review of the airframe logbook revealed that the landing gear actuator (part number 4196-00-1C) was removed and replaced on February 16, 2009. Following its replacement, maintenance personnel cycled the landing gear five times, checked the emergency (manual) landing gear disengage system, and manually extended the landing gear. There were no other entries pertaining to the emergency gear extension system in the airframe logbook; however, the logbook entry for the most recent 100-hour inspection noted "performed three landing gear retraction cycles." The airplane's mostrecent 100 hour inspection was completed on May 24, 2012. Review of a Mooney Maintenance Manual, 100 Hour-Annual Inspection Guide, revealed "8. Check emergency landing gear extension system; extend gear using emergency gear extension system." The mechanic that had completed the most recent 100 hour inspection reported that he typically does more than the standard airframe logbook entry of three landing gear retraction cycles, with the first one being done manually (emergency), which was what he performed on the accident airplane. The mechanic added that the standard logbook entry does not differentiate between normal or emergency gear retraction cycles. Additionally, he was very familiar with that airplane as he had owned it for 14 years prior to its current owner and did not experience any problems with the landing gear system during the most recent inspection or prior. At the time of the most recent 100 hour inspection, the airplane had accumulated 3,497.9 total hours of operation. The airplane had accumulated an additional 59 hours of operation, from the time of the last annual inspection, until the accident. ## Aircraft - Registration: [N9387V](https://openairdocs.org/aircraft/N9387V), registered now, S/N 700018, built 1969 (OpenAirDocs) - Reported make and model: MOONEY M20F - Registry model: [Mooney M20F](https://openairdocs.org/model/mooney-m20f) (registry code 5870214) (OpenAirDocs) - Registry engine: [Lycoming I0360 series](https://openairdocs.org/engine/lycoming-i0360-series) (registry code 41515, reciprocating) (OpenAirDocs) - Category: Airplane - Serial number: 700018 - Airframe hours: 3498 - Engines: Lycoming IO-360 200 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Operator: Paul S Soule - Registered owner: Paul S Soule - Airworthiness certificate: Standard, Normal - Last inspection: Annual, May 24, 2012, 59 hours before - Departed: LEE, Leesburg, FL - Destination: LEE, Leesburg, FL - Airport: LEE, Leesburg International Airport ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 75; injuries: none; commercial; airplane ratings: single-engine land, multi-engine land; instrument ratings: airplane; medical: class 2, with waivers/limitations; last flight review July 6, 2012; seat: left; flight hours: 17,000 total, 50 in this make and model, 16,800 as pilot in command, 90 in the last 90 days, 9 in the last 30 days, 1 in the last 24 hours ## Weather - Conditions: Visual (VMC), Day - Wind: 200° at 5 knots - Lowest ceiling: none - Temperature: 70 °F, dew point 45 °F - Altimeter: 30.19 inHg - Observed at: LEE ## 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 20130316003559A](https://openairdocs.org/incident/20130316003559A), Mar 16, 2013: Mooney M20F, Leesburg, FL, Substantial damage. The aircraft departed Leesburg for a local flight to the practice area west of the field. Practice maneuvers were performed prior to slow flight. When the gear… ## Docket (10 files) The files NTSB released with the investigation on June 13, 2013, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=86465. 3.3 MB in all. - Pilot/Operator Aircraft Accident Report, NTSB Form 6120.1 (item 1, .PDF, 1.2 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40390170&FileExtension=.PDF&FileName=Pilot%2FOperator%20Aircraft%20Accident%20Report,%20NTSB%20Form%206120.1-Redacted.PDF - Interview Summary (item 2, .PDF, 51 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40392402&FileExtension=.PDF&FileName=Interview%20Summary-Master.PDF - Interview Summary (item 3, .PDF, 52 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40395546&FileExtension=.PDF&FileName=Interview%20Summary-Master.PDF - Correspondence From Mechanic (item 4, .PDF, 20 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40390175&FileExtension=.PDF&FileName=Correspondence%20From%20Mechanic%20-Redacted.PDF - Excerpts From Airframe Logbook (item 5, .PDF, 624 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40392403&FileExtension=.PDF&FileName=Excerpts%20From%20Airframe%20Logbook-Redacted.PDF - Excerpt From Mooney Maintenance Manual (item 6, .PDF, 525 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40395547&FileExtension=.PDF&FileName=Excerpt%20From%20Mooney%20Maintenance%20Manual-Master.PDF - Landing Gear Actuator Illustrations (item 7, .PDF, 382 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40392751&FileExtension=.PDF&FileName=Landing%20Gear%20Actuator%20Illustrations-Master.PDF - Photograph # 1: Empennage Damage (Photo Courtesy of FAA) (item 8, .PDF, 153 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40390173&FileExtension=.PDF&FileName=Photograph%20%23%201%3A%20%20Empennage%20Damage%20(Photo%20Courtesy%20of%20FAA)-Master.PDF - Photograph # 2: Emergency Landing Gear Extension Cable Spine Drive (Photo Courtesy of Holmes) (item 9, .PDF, 186 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40390172&FileExtension=.PDF&FileName=Photograph%20%23%202%3A%20%20Emergency%20Landing%20Gear%20Extension%20Cable%20Spine%20Drive%20(Photo%20Courtesy%20of%20Holmes)-Master.PDF - Photograph # 3: Landing Gear Motor And Housing (Photo Courtesy of Holmes) (item 10, .PDF, 131 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=40390174&FileExtension=.PDF&FileName=Photograph%20%23%203%3A%20%20Landing%20Gear%20Motor%20And%20Housing%20(Photo%20Courtesy%20of%20Holmes)-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.