OpenAirDocs.org

Main rotor system, general

Open the Markdown

NTSB finding · Aircraft › Aircraft propeller/rotor › Main rotor system

All 25 cases23 in the probable cause
Cases
25
In the probable cause
23 (92%)
Fatal cases
4
NTSB code
01046200

NTSB has coded findings and defining events since 2008. Earlier cases used its older occurrence and cause codes, so they aren’t counted here.

When and where

In green, cases where NTSB made it part of the probable cause; in gray, a factor or other finding. Findings are coded with the final report, often a year or more after the event, so the latest years are incomplete.

Cases per year

2008In the probable causeFactor only2026

Where

Open the map
Query with SQL
duckdb -csv -c "SELECT year(c.\"eventDate\") AS year, count(DISTINCT f.case_mkey) AS cases,
    count(DISTINCT f.case_mkey) FILTER (WHERE f.\"inProbableCause\") AS in_probable_cause
  FROM 'https://openairdocs.org/data/latest/ntsb_findings.parquet' f JOIN 'https://openairdocs.org/data/latest/ntsb_case_detail.parquet' c ON c.\"mKey\" = f.case_mkey
  WHERE starts_with(f.\"findingCode\", '01046200') AND c.\"eventDate\" >= DATE '2000-01-01'
  GROUP BY 1
  ORDER BY 1"

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

In the same cases

Defining events
Aircraft models

Aircraft matched to the registry by N-number and date.

Other findings
Query with SQL
duckdb -csv -c "WITH matched AS (SELECT DISTINCT case_mkey, aircrafts_position FROM 'https://openairdocs.org/data/latest/ntsb_findings.parquet' WHERE starts_with(\"findingCode\", '01046200'))
  SELECT * FROM (
  SELECT 'Defining event' AS kind, e.\"tier2Number\" AS code, max(e.\"eventTier2Name\") AS name, count(DISTINCT f.case_mkey) AS cases
  FROM matched f JOIN 'https://openairdocs.org/data/latest/ntsb_events.parquet' e ON e.case_mkey = f.case_mkey AND e.aircrafts_position = f.aircrafts_position AND e.\"isDefiningEvent\"
  WHERE e.\"tier2Number\" <> ''
  GROUP BY ALL
  UNION ALL
  SELECT 'Aircraft model', a.aircraft_model_code, any_value(concat_ws(' ', m.manufacturer, m.model)), count(DISTINCT f.case_mkey)
  FROM matched f JOIN 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' a ON a.case_mkey = f.case_mkey AND a.position = f.aircrafts_position
  LEFT JOIN 'https://openairdocs.org/data/latest/faa_aircraft_model.parquet' m ON m.code = a.aircraft_model_code
  WHERE a.aircraft_model_code IS NOT NULL
  GROUP BY ALL
  UNION ALL
  SELECT 'Other finding', left(g.\"findingCode\", 8), max(g.\"tier4Name\"), count(DISTINCT g.case_mkey)
  FROM 'https://openairdocs.org/data/latest/ntsb_findings.parquet' g
  WHERE g.case_mkey IN (SELECT case_mkey FROM matched) AND NOT starts_with(g.\"findingCode\", '01046200') AND g.\"findingCode\" GLOB '[0-9][0-9]*'
  GROUP BY ALL
  )
  QUALIFY row_number() OVER (PARTITION BY kind ORDER BY cases DESC) <= 10
  ORDER BY kind, cases DESC"

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

Newest cases · 25

NTSB WPR25LA010Accident · No injuriesClass 4 · LimitedFinal reportEnstrom Helicopter 280C · Vale, ORThe pilot’s failure to maintain engine and rotor rpm during takeoff, that resulted in a hard landing.Oct 9, 2024 · N646H · Substantial damageNTSB CEN24LA013Accident · No injuriesClass 3 · LimitedFinal reportMagni M24 · Mount Sterling, ILThe pilot’s failure to maintain gyroplane control on the downwind leg, which resulted in impact with terrain. Contributing to the accident was the pilot’s distraction.Oct 16, 2023 · N90HM · Substantial damageNTSB CEN22LA318Accident · Serious injuriesClass 3 · LimitedFinal reportHiller UH12E · Becker, MNThe in-flight failure of the main rotor mast hub due to several undetected fatigue fractures.Jul 6, 2022 · N64272 · Substantial damageNTSB ERA21LA126Accident · No injuriesClass 3 · LimitedFinal reportBell 206 · Pahokee, FLA loss of main rotor rpm for reasons that could not be determined, which resulted in an autorotation and a subsequent hard landing and rollover.Feb 4, 2021 · N820H · Substantial damageNTSB ERA17LA257Accident · No injuriesLimited investigationFinal reportRobinson Helicopter R44 · Myrtle Beach, SCA loss of available power to the main rotor due to a fractured exhaust pushrod and housing, which allowed engine oil to coat the V-belts. Contributing to the accident was the pilot's decision to continue the tour and his failure to maintain adequate rotor rpm…Jul 24, 2017 · N828RD · Substantial damageNTSB WPR16LA069Accident · Minor injuriesLimited investigationFinal reportBell 47G 3B 1 · Carson City, NVThe pilot's failure to maintain sufficient main rotor rpm, which resulted in a loss of helicopter control and a dynamic rollover.Feb 13, 2016 · N1181W · Substantial damageNTSB CEN16LA040Accident · Minor injuriesLimited investigationFinal reportRobinson Helicopter R22 Beta · Sugarland, TXThe overspeed of the main rotor system for reasons that could not be determined based on the available information.Nov 14, 2015 · N7058Z · Substantial damageNTSB GAA15LA191Accident · Minor injuriesLimited investigationFinal reportCelier Xenon RST · Livingston, TXThe pilot’s loss of directional control after aborting the takeoff due to a grinding noise coming from the main rotor area, which resulted in a runway excursion.Jul 17, 2015 · N402ED · Substantial damageNTSB WPR15LA178Accident · No injuriesLimited investigationFinal reportGarlick Helicopters UH 1H · Cove, ORThe failure of the engine-to-transmission drive shaft coupling assembly due to a fatigue fracture of one of its attachment bolts, which resulted in a loss of power to the main rotor.May 31, 2015 · N462CC · Substantial damageNTSB CEN15FA126Accident · 2 fatalField investigationFinal reportEnstrom 280FX · Erie, COAn in-flight failure of the helicopter's #2 main rotor spindle due to undetected fatigue cracking, which resulted in an in-flight breakup. Contributing to failure were the nonconforming thread root radius of the spindle and the manufacturer's failure to…Jan 26, 2015 · N86235 · Destroyed
See all 25 cases
Query with SQL
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\", '01046200'))
  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.