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Main rotor system

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NTSB finding section · Aircraft › Aircraft propeller/rotor

All 104 cases92 in the probable cause
Cases
104
In the probable cause
92 (88%)
Fatal cases
32
NTSB code
010462

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\", '010462') 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.

Subsections · 5

Query with SQL
duckdb -csv -c "SELECT left(f.\"findingCode\", 8) AS code, max(f.\"tier4Name\") AS name,
    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
  WHERE starts_with(f.\"findingCode\", '010462') AND f.\"findingCode\" GLOB '[0-9][0-9]*'
  GROUP BY 1
  ORDER BY cases DESC, code"

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\", '010462'))
  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\", '010462') 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 · 104

NTSB CEN26LA081Accident · No injuriesClass 4 · LimitedFinal reportEla ELA10 · Morris, ILThe pilot’s failure obtain the proper rotor rpm before applying power for the takeoff roll which resulted in a loss of control.Dec 23, 2025 · N396S · Substantial damageNTSB WPR25LA203Accident · No injuriesClass 4 · LimitedFinal reportRobinson Helicopter R44 · Park City, UTThe pilot’s failure to maintain rotor rpm during an approach to landing in a mountainous area, which resulted in a collision with terrain.Jul 6, 2025 · N715SG · Substantial damageNTSB WPR25LA093Accident · No injuriesClass 4 · LimitedFinal reportAirbus Helicopters EC 130 T2 · Moab, UTThe inflight collision with debris during takeoff.Feb 13, 2025 · N3WL · Substantial damageNTSB 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 WPR24LA319Accident · No injuriesClass 3 · LimitedFinal reportBell 206L · Fern Prairie, WAAn aeroelastic interaction between the helicopter’s main rotor blades and nodal beam system, which resulted in oscillations that exceeded the design limits of the tailboom. Contributing to the accident was the failure of the main rotor blade manufacturer to…Sep 26, 2024 · N9984K · Substantial damageNTSB CEN24LA358Accident · No injuriesClass 3 · LimitedFinal reportHughes 369 · Canton, MIFatigue cracking of the main rotor blade that occurred at an undetermined time.Sep 11, 2024 · N8969F · Substantial damageNTSB ANC24FA063Accident · 3 fatalClass 3 · FieldFinal reportRobinson Helicopter R44 · Kekaha, HIAn encounter with turbulence due to downdraft winds that resulted in mast bumping and an in-flight breakup.Jul 11, 2024 · N144KW · 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 WPR23LA313Accident · Minor injuriesClass 3 · LimitedFinal reportBell OH-58A · Guernsey, CAThe pilot’s overpitching of the main rotor blades while maneuvering at low altitude in a high-temperature environment at high gross weight, which resulted in a reduction of engine and rotor speed, excessive main rotor blade flapping, mast bumping, and impact…Aug 9, 2023 · N861CC · Substantial damageNTSB ERA23LA326Accident · Serious injuriesClass 4 · LimitedFinal reportHughes 369 · Elberon, VAThe pilot’s failure to maintain clearance from a power line structure arm, which resulted in main rotor blade contact.Aug 5, 2023 · N353AH · Substantial damage
See all 104 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\", '010462'))
  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.