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Propeller governor

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

All 16 cases
Cases
16
In the probable cause
16 (100%)
Fatal cases
3
NTSB code
01046122

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\", '01046122') 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\", '01046122'))
  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\", '01046122') 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 · 16

NTSB CEN24LA187Accident · Serious injuriesClass 4 · LimitedFinal reportAviat A1 · Poole, NEThe non-certificated pilot’s failure to configure the airplane for takeoff, which resulted in a runway excursion.Feb 11, 2024 · N122HU · Substantial damageNTSB CEN24LA061Accident · No injuriesClass 3 · LimitedFinal reportCessna 421C · McGregor, TXThe failure of the spring pin in the right propeller governor, which precluded the pilot from controlling the propeller pitch to maintain engine rpm, resulting in a loss of engine thrust, excessive drag, and the subsequent forced landing to a field.Dec 8, 2023 · N146TJ · Substantial damageNTSB WPR21LA208Accident · Minor injuriesClass 3 · LimitedFinal reportBoeing A75N1(PT17) · Hollister, CAThe improper installation of a relief valve spring that was shorter than the standard spring length, which slowed the response of the propeller governor to change the pitch of the blades during climbout, resulting in a partial loss of power.May 26, 2021 · N75016 · Substantial damageNTSB ERA19LA232Accident · Minor injuriesClass 3 · LimitedFinal reportVans RV7 · Ocean City, MDThe disconnection of the propeller governor control arm from the propeller governor due to a missing attachment bolt, which resulted in a partial loss of engine power during takeoff when the governor control vibrated to a high pitch, low rpm setting.Jul 19, 2019 · N849GS · Substantial damageNTSB ERA19LA096Accident · 1 fatalLimited investigationFinal reportConvair C131 · Atlantic Ocean (Atlantic Ocean)The captain's decision to continue with the flight with a malfunctioning left engine propeller control and the subsequent loss of engine power on both engines for undetermined reasons, which resulted in ditching into the ocean. Contributing to the accident…Feb 8, 2019 · N145GT · DestroyedNTSB WPR18FA131Accident · 1 fatalField investigationFinal reportAmerican Air Racing Thunder Mustang · Reno, NVThe pilot's failure to properly secure the engine coolant pump pulley during recent maintenance, which resulted in a loss of the engine's lubrication, cooling, and propeller control systems, and a forced landing, during which the airplane nosed over.…May 2, 2018 · N352BT · Substantial damageNTSB ERA18LA021Accident · No injuriesClass 2 · LimitedFinal reportSocata TB200 · Annapolis, MDA loss of engine power for undetermined reasons after the disconnection of the propeller governor control due to inadequate securenment during maintenance.Nov 10, 2017 · N207GT · Substantial damageNTSB WPR16FA095Accident · 1 fatalField investigationFinal reportMooney M20K · Woodland, WAThe pilot's delay in recognizing that the airplane was not performing as expected and aborting the takeoff, which resulted in collision with a berm beyond the end of the runway. Contributing to the accident were the pilot's exceedance of the airplane's gross…Apr 21, 2016 · N97119 · Substantial damageNTSB CEN15IA365Incident · No injuriesIncident investigationFinal reportBeech V35 · Mount Vernon, OHThe loosening of the flyweight due to the installation of an improperly hardened flyweight carrier, which resulted in the overspeed of the propeller and engine and the subsequent in-flight separation of the propeller.Aug 16, 2015 · N2059W · No damageNTSB CEN15LA298Accident · Minor injuriesLimited investigationFinal reportCirrus Design SR22 · Houston, TXMaintenance personnel's improper installation of the propeller governor, which resulted in damage to the governor drive gear and its subsequent failure and a subsequent loss of engine power.Jul 7, 2015 · N422PB · Substantial damage
See all 16 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\", '01046122'))
  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.