Skip to content

NTSB investigations

24 cases where NTSB found Engine/transmission coupling.

Defining event

Finding

Phase of flight

Aircraft model

Cases per year

20082026

Where

Latest cases

Query with SQL

SELECT c."ntsbNumber", c."eventDate", c."eventType", c."eventCity", c."eventStateOrRegion", a.n_number, a."aircraftMake", a."aircraftModel", c."highestInjuryLevel", c."totalFatal", c."completionStatus", c.report_url FROM 'https://openairdocs.org/data/latest/ntsb_case_detail.parquet' c LEFT JOIN 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' a ON a.case_mkey = c."mKey" AND a.position = 1 WHERE c."mKey" IN (SELECT f.case_mkey FROM 'https://openairdocs.org/data/latest/ntsb_findings.parquet' f WHERE starts_with(f."findingCode", '01046310')) ORDER BY c."eventDate" DESC, c."ntsbNumber" DESC

duckdb -csv -c "SELECT c.\"ntsbNumber\", c.\"eventDate\", c.\"eventType\", c.\"eventCity\", c.\"eventStateOrRegion\", a.n_number, a.\"aircraftMake\", a.\"aircraftModel\", c.\"highestInjuryLevel\", c.\"totalFatal\", c.\"completionStatus\", c.report_url
  FROM 'https://openairdocs.org/data/latest/ntsb_case_detail.parquet' c LEFT JOIN 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' a ON a.case_mkey = c.\"mKey\" AND a.position = 1
  WHERE c.\"mKey\" IN (SELECT f.case_mkey FROM 'https://openairdocs.org/data/latest/ntsb_findings.parquet' f WHERE starts_with(f.\"findingCode\", '01046310'))
  ORDER BY c.\"eventDate\" DESC, c.\"ntsbNumber\" DESC"

Prints the whole list as CSV. It reads the release’s Parquet files over HTTPS, so there’s nothing to download first. Install DuckDB to run it.

SELECT c."ntsbNumber", c."eventDate", c."eventType", c."eventCity", c."eventStateOrRegion", a.n_number, a."aircraftMake", a."aircraftModel", c."highestInjuryLevel", c."totalFatal", c."completionStatus", c.report_url
FROM 'https://openairdocs.org/data/latest/ntsb_case_detail.parquet' c LEFT JOIN 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' a ON a.case_mkey = c."mKey" AND a.position = 1
WHERE c."mKey" IN (SELECT f.case_mkey FROM 'https://openairdocs.org/data/latest/ntsb_findings.parquet' f WHERE starts_with(f."findingCode", '01046310'))
ORDER BY c."eventDate" DESC, c."ntsbNumber" DESC

Run it at the DuckDB prompt, or in any tool that reads Parquet over HTTPS. More ways to query the release are on Use the data.

NTSB ANC24LA017Accident · Serious injuriesClass 3 · LimitedFinal reportMD Helicopter 369E/500E · Kekaha, HIMaintenance personnel’s noncompliance with maintenance manual procedures that required the removal of the overrunning clutch output bearing during the regreasing procedure, which resulted in inadequate regreasing of the bearing and the subsequent failure of…Feb 27, 2024 · N633JH · Substantial damage NTSB ERA23LA293Accident · Minor injuriesClass 3 · LimitedFinal reportHughes 369D · Waldorf, MDFatigue failure of the overrunning clutch outer race and a subsequent inflight loss of power due to abnormal bending loads as a result of improper reassembly of the clutch subassembly following maintenance and the presence of microcracks on the clutch’s outer…Jul 9, 2023 · N5027P · Substantial damage NTSB ERA22LA256Accident · No injuriesClass 3 · LimitedFinal reportRobinson Helicopter R44 · North Myrtle Beach, SCThe fractured attachment lug on the forward clutch shaft yoke due to fatigue failure with multiple origins.May 26, 2022 · N132TC · Substantial damage NTSB ANC21LA038Accident · No injuriesClass 3 · LimitedFinal reportEnstrom F-28F · Palmer, AKA loss of drive to the rotor system due to the disengagement of the main belt drive tensioning system, which resulted in a forced landing. The disengagement was due to inadequate clearance between the clutch handle and the roll pin in the handle bellcrank…May 9, 2021 · N8627J · Substantial damage NTSB WPR20LA228Accident · No injuriesClass 3 · LimitedFinal reportMd Helicopter 600 · San Andreas, CAThe failure of the output shaft of the overrunning clutch inner race due to frictional overheating of the shaft, which resulted from the failure of the output bearing’s stainless-steel grease seal.Jul 20, 2020 · N745BW · Destroyed NTSB ERA20LA054Accident · Minor injuriesClass 3 · LimitedFinal reportRobinson R44 · San Antonio, TXMaintenance personnel’s failure to complete all necessary steps of a service bulletin and subsequent failure to identify the loose lower actuator bearing support bracket during inspections, which resulted in the misalignment of the clutch actuator, resulted…Dec 14, 2019 · N440AH · Substantial damage NTSB CEN19LA240Accident · Minor injuriesClass 3 · LimitedFinal reportRobinson R44 · Blair, NEThe failure of the lower actuator bearing support bracket, which resulted in the misalignment of the clutch actuator, the loss of belt tension on the main rotor drive system, and the subsequent forced landing on sloped terrain.Jul 27, 2019 · N7508Z · Substantial damage NTSB CEN19LA106Accident · No injuriesClass 3 · LimitedFinal reportRobinson R22 · Madill, OKThe failure of the V-belts due to improper maintenance, which resulted in the loss of power to the helicopter's rotor system and subsequent forced landing on rough terrain.Mar 20, 2019 · N7782H · Substantial damage NTSB ERA19FA118Accident · 1 fatalClass 3 · FieldFinal reportHughes 369 · Talking Rock, GAA fatigue failure of the overrunning clutch subassembly due to abnormal bending loads due to cracks on the center engine mount, which resulted in an inflight loss of power. Contributing to the accident was the helicopter's low altitude and airspeed when the…Mar 5, 2019 · N89ZC · Substantial damage NTSB CEN18LA334Accident · No injuriesClass 3 · LimitedFinal reportSchweizer 269C · Kindred, NDThe pilot’s failure to adequately inspect the lower coupling driveshaft during his preflight inspection and his non-compliance with an applicable airworthiness directive, which resulted in the failure of the forward drive splines of the lower coupling…Aug 16, 2018 · N3625Z · Destroyed NTSB WPR18FA088Accident · 4 fatalField investigationFinal reportHastings Thomas G Cirrus VK 30 · Agua Dulce, CAThe driveshaft fracture due to overstress loading and rotational bending as a result of the under-torqued nuts on the elastomeric couplings backing off and the subsequent in-flight separation of the horizontal fairing due to contact with the separated end of…Feb 11, 2018 · N52TH · Substantial damage NTSB WPR17LA113Accident · Serious injuriesLimited investigationFinal reportBell 206B · Rockville, IDThe in-flight failure of the engine-to-transmission drive shaft due to a fatigue fracture of one of the KAflex flex frames caused by a loose bolt, which resulted in a total loss of engine power and a subsequent hard landing.May 26, 2017 · N24FS · Substantial damage NTSB WPR16FA072Accident · 1 fatalField investigationFinal reportBell 206B · Honolulu, HIThe in-flight failure of the engine-to-transmission drive shaft due to improper maintenance, which resulted in low main rotor rpm and a subsequent hard landing to water.Feb 18, 2016 · N80918 · Substantial damage NTSB CEN16LA105Accident · No injuriesLimited investigationFinal reportEnstrom TH-180 · Menominee, MIThe failure of the torque meter mounting bolts, which resulted in a loss of engine power to the main drive belt and rotors.Feb 12, 2016 · N180TH · Substantial damage NTSB CEN15LA396Accident · No injuriesLimited investigationFinal reportBurns Mini 500 · Butler, MOThe pilot's failure to attain a proper landing flare following an autorotation for reasons that could not be determined based on available information.Aug 21, 2015 · UNREG · Substantial damage NTSB CEN15CA155Accident · No injuriesData collectionFinal reportGaddis Michael Exec 162 F · Plymouth, INThe failure of the helicopter's main drive belt resulting in the pilot performing a forced landing, during which the helicopter's fuselage was substantially damage.Feb 26, 2015 · N123XZ · Substantial damage NTSB WPR15LA109Accident · No injuriesLimited investigationFinal reportBell/Garlick UH 1H · Shelton, WAThe fatigue failure of the engine-to-transmission driveshaft adapter attachment bolt due to the application of inadequate torque on the bolt during assembly.Feb 19, 2015 · N166DR · Substantial damage NTSB ERA14LA099Accident · Minor injuriesLimited investigationFinal reportBell 47D1 · Pell City, ALThe pilot’s use of an improper clutch engagement procedure, which resulted in clutch glazing, slippage, and, ultimately, the in-flight disengagement of the clutch and a loss of rotor rpm. Contributing to the accident were the installation of a light-weight…Jan 21, 2014 · N93067 · Substantial damage NTSB WPR14LA062Accident · No injuriesLimited investigationFinal reportHiller UH 12E · Chowchilla, CAThe failure of the torsional drive coupling, which resulted in a loss of drive to the main rotor system during low-altitude flight.Dec 9, 2013 · N36MV · Substantial damage NTSB CEN12LA228Accident · Minor injuriesLimited investigationFinal reportEnstrom 280FX · Corpus Christi, TXThe failure of the bolt that retained the clutch drive rod end, which resulted in a loss of main rotor drive and a subsequent hard landing.Apr 3, 2012 · N3042D · Substantial damage NTSB ERA11LA204Accident · No injuriesLimited investigationFinal reportRobinson R22 · Goshen, NYThe pilot’s failure to adhere to published preflight checklist limitations and procedures, resulting in excessive slack and subsequent failure of the power transmission belts and a total loss of rotor system drive.Mar 22, 2011 · N259TW · Substantial damage NTSB WPR11LA167Accident · No injuriesLimited investigationFinal reportRotorway A600 · Chandler, AZA design modification that changed the fasteners and components used to attach the main rotor drive pulley to the engine, which resulted in fatigue failure of those fasteners and a complete loss of power to the main rotor.Mar 15, 2011 · N602RW · Substantial damage NTSB WPR10FA112Accident · No injuriesField investigationFinal reportEurocopter AS350 B3 · Reno, NVThe improper installation of the engine-to-main gear box flex coupling, which resulted in the failure of the flex coupling and a loss of power to the rotor system during takeoff. Contributing to the accident was the mechanic who removed the engine's failure…Jan 17, 2010 · N904CF · Substantial damage NTSB ANC08FA053Accident · 4 fatalField investigationFinal reportEurocopter AS 350 B2 · Chickaloon, AKAn in-flight overtorque of the engine-to-transmission driveshaft resulting in disconnection of the main transmission from the engine. The overtorque likely occurred due to an in-flight main rotor blade contact with snow-covered terrain, precluding significant…Apr 15, 2008 · N213EH · Substantial damage