# NTSB CEN24LA234: Mooney M20J, N123WJ, Ava, MO, June 14, 2024 - Type: NTSB accident investigation - Classification: Accident · Minor injuries · Class 4 · Limited · Final report - Date: June 13, 2024, 20:15 local (Jun 14, 2024, 01:15 UTC) - Place: Ava, MO · grass field - Coordinates: 36.971887, -92.681946 (estimated) - Nearby events: https://openairdocs.org/map.md?lat=36.9719&lon=-92.6819&mi=10 - Phase of flight: [Landing](https://openairdocs.org/ntsb-phases/550) (OpenAirDocs' grouping) - Defining event: [Landing: Runway excursion](https://openairdocs.org/ntsb-events/300) - Highest injury: Minor injuries - Injuries: 1 minor, 3 uninjured - Status: Completed - Report: Approved by Office Director - Investigation class: Class 4 - Basic report with no Prelim publish - NTSB office: Central Region - Parties: FAA Flight Standards - NTSB case key (mKey): 194521 - NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=CEN24LA234 - NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/194521/pdf - NTSB docket: https://data.ntsb.gov/Docket?ProjectID=194521 - Page: https://openairdocs.org/ntsb/CEN24LA234 ## Probable cause The pilot’s failure to maintain control of the airplane resulting in a runway excursion during landing. Contributing to the accident was the degraded brake system on the airplane. ## Findings NTSB's coded findings; those marked are part of the probable cause. - [Landing gear system: brake](https://openairdocs.org/ntsb-findings/01023242): Aircraft › Aircraft systems · Damaged/degraded; cases with it: [Mooney M20J, 2 cases](https://openairdocs.org/ntsb-findings/01023242/cases.md?model=5870219), [All aircraft, 297 cases](https://openairdocs.org/ntsb-findings/01023242/cases.md) - [Use of equip/info: aircraft control](https://openairdocs.org/ntsb-findings/02063040): Personnel issues › Task performance · Pilot (probable cause); cases with it: [Mooney M20J, 36 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md?model=5870219), [All aircraft, 9,295 cases](https://openairdocs.org/ntsb-findings/02063040/cases.md) ## Sequence of events The events NTSB coded, in order, by phase of flight. The defining event best describes what happened. - [Landing: Runway excursion](https://openairdocs.org/ntsb-events/300) (defining event); cases with it: [Mooney M20J, 21 cases](https://openairdocs.org/ntsb-events/300/sequence.md?model=5870219), [All aircraft, 3,643 cases](https://openairdocs.org/ntsb-events/300/sequence.md) ## Analysis The pilot reported that after landing, he moved the throttle to idle; however, the engine speed remained at 1,550 rpm. After verifying that the throttle friction lock was fully released, he decided to move the mixture control to idle/cutoff to stop the engine. The airplane subsequently went off the end of the runway and impacted some bushes. The left wing separated at the wing root during the impact sequence. He noted that a throttle linkage issue may have prevented the engine from reducing to idle power. An examination conducted by a Federal Aviation Administration inspector confirmed throttle control continuity from the cockpit to the fuel servo, and that the fuel servo throttle arm rotated smoothly from stop to stop. Additionally, the left and right wheel brakes appeared to be leaking, and the pads were worn below minimums. In a supplemental statement, the pilot noted that the brakes were functional but required more pressure than normal. He added that there was no issue holding the airplane in place during the before takeoff engine runup. The airplane pilot operating handbook (POH) specified an engine speed of 1,900 – 2,000 rpm for the before takeoff engine runup. Automatic Dependent Surveillance – Broadcast (ADS-B) data depicted the airplane approaching to land on an extended final. The final data point was located about 0.5 miles from the runway. At that time, the airplane groundspeed was about 108 knots. Additionally, a left quartering tailwind prevailed which provided a 3-knot tailwind component to the landing runway. The airplane POH specified a final approach airspeed of 71 knots. There was no evidence of an anomaly with respect to the throttle linkage. However, there was evidence that the wheel brakes were likely not performing at an optimal level. The brakes in combination with the airplane inertia during landing likely resulted in the runway excursion. ## Aircraft - Registration: [N123WJ](https://openairdocs.org/aircraft/N123WJ), registered now, S/N 24-1620 (OpenAirDocs) - Reported make and model: MOONEY M20J - 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: 24-1620 - Year built: 1987 - Airframe hours: 4041 - Engines: Lycoming IO-360-A3B6D 200 horsepower reciprocating - Damage: Substantial damage - Flight: Personal, Part 91 - Airworthiness certificate: Standard, Normal - Last inspection: Annual, January 1, 2024, 22.5 hours before - Departed: MOR, Morristown, TN - Destination: AOV, Ava, MO - Airport: AOV, Ava Bill Martin Memorial, runway 31, 3,634 × 50 ft, asphalt - Equipment: Electronic primary flight display, Stall warning system, Auto-pilot, ADS-B ## Flight crew As NTSB recorded them. NTSB leaves out names. - Pilot; age 34; injuries: none; private; airplane ratings: single-engine land; instrument ratings: airplane; medical: class 3, without waivers/limitations; last flight review November 30, 2023; seat: left; restraint: 3-point; flight hours: 462 total ## Weather - Conditions: Visual (VMC), Day - Wind: 190° at 7 knots - Visibility: 11 statute miles - Lowest ceiling: none - Temperature: 79 °F, dew point 70 °F - Altimeter: 29.89 inHg - Observed at: KSGF, 38 nm away - METAR: METAR KSGF 140152Z 19007KT 10SM CLR 26/21 A2989 ## Docket (8 files) The files NTSB released with the investigation on December 6, 2024, on NTSB's docket system: https://data.ntsb.gov/Docket?ProjectID=194521. 20.0 MB in all. - Pilot/operator aircraft accident report, NTSB form 6120.1 (item 1, PDF, 9 pages, 3.6 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17304617&FileExtension=pdf&FileName=Accident%20Report%20--%20CEN24LA234_redacted-Rel.pdf - Pilot statement (item 2, PDF, 1 page, 68 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17360445&FileExtension=pdf&FileName=ROC%20--%20Pilot_09Jul2024-Rel.pdf - FAA inspector statement (item 3, PDF, 1 page, 68 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17360152&FileExtension=pdf&FileName=ROC%20--%20FAA(Davis)_25Jun2024-Rel.pdf - Pilot operating handbook -- before takeoff procedure (item 4, PDF, 2 pages, 79 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17360170&FileExtension=pdf&FileName=M20J%20POH%20--%20Before%20Takeoff%20Procedure-Rel.pdf - Pilot operating handbook -- approach and landing procedure (item 5, PDF, 4 pages, 178 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17971478&FileExtension=pdf&FileName=M20J%20POH%20--%20Approach%20and%20Landing%20Procedure-Rel.pdf - FAA chart supplement -- bill martin memorial airport (kaov) (item 6, PDF, 1 page, 57 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17382686&FileExtension=pdf&FileName=FAA%20Chart%20Supplement%20--%20Bill%20Martin%20Meml%20Arpt_AvaMO-Rel.pdf - ADS-B data file (item 7, CSV, 15.3 MB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17971313&FileExtension=csv&FileName=CEN24LA234_ADSB-Rel.csv - ADS-B data file -- google earth format (item 8, KMZ, 647 KB): https://data.ntsb.gov/Docket/Document/docBLOB?ID=17971149&FileExtension=kmz&FileName=CEN24LA234_ADSB_GEarth-Rel.kmz 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.