OpenAirDocs.org

Tail rotor control system

Open the Markdown

NTSB finding · Aircraft › Aircraft propeller/rotor › Rotorcraft flight control

All 13 cases
Cases
13
In the probable cause
13 (100%)
Fatal cases
1
NTSB code
01046720

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\", '01046720') 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\", '01046720'))
  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\", '01046720') 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 · 13

NTSB CEN22LA009Accident · Minor injuriesClass 3 · LimitedFinal reportBell 206 · Gonzales, LAThe student pilot’s failure to compensate for an unanticipated right yaw, which resulted in a loss of tail rotor effectiveness and helicopter control.Oct 6, 2021 · N373SP · Substantial damageNTSB WPR21LA039Accident · Serious injuriesClass 3 · LimitedFinal reportAgusta A109 · Los Angeles, CAThe loss of tail rotor control due to the separation of the tail rotor duplex bearing ring nut from the thrust sleeve, which resulted in the loss of helicopter control.Nov 6, 2020 · N109EX · Substantial damageNTSB GAA19CA403Accident · Minor injuriesData collectionFinal reportMd Helicopter 369 · Summersville, SCThe copilot’s disabling of the flight controls of an operating helicopter without telling the pilot on the controls, which resulted in a subsequent loss of control and collision with terrain.Jun 26, 2019 · N500SC · Substantial damageNTSB CEN18LA290Accident · Minor injuriesLimited investigationFinal reportBell 206 · Todd Mission, TXThe passenger’s inadvertent interference with the tail rotor pedals, which resulted in a loss of helicopter control during takeoff and the subsequent impact with terrain.Jul 20, 2018 · N352CT · Substantial damageNTSB GAA16LA182Accident · Serious injuriesLimited investigationFinal reportHughes 369 · Weatherford, TXThe pilot/mechanic's inadequate postmaintenance and preflight inspections, which resulted in his failure to remove the antitorque pedal lock and a subsequent loss of control during hover operations.Apr 8, 2016 · N298SD · Substantial damageNTSB GAA16CA075Accident · No injuriesData collectionFinal reportRobinson Helicopter R44 · West Palm Beach, FLThe student pilot's failure to maintain directional control during the landing, which resulted in a horizontal rotation of the helicopter, and abnormal runway contact.Dec 9, 2015 · N4427H · Substantial damageNTSB ERA15LA374Accident · No injuriesLimited investigationFinal reportBell 206 · Thomaston, GAThe loss of tail rotor control due to a fractured pin in the tail rotor control system; the reason the pin fractured could not be determined as the fractured pin was lost in shipping.Sep 20, 2015 · N165BH · DestroyedNTSB ANC15LA015Accident · No injuriesLimited investigationFinal reportAirbus AS350 B2 · Anchorage, AKThe failure of the ball bearing within the pitch change spider assembly due to its operation with no grease within the bearing, which resulted in the subsequent fracture of the spider assembly and a loss of tail rotor control authority. Also causal to the…Mar 13, 2015 · N814EH · Substantial damageNTSB CEN11WA412Accident · Serious injuriesForeign investigationMcDonnell Douglas Helicopter 369E · Glastonbury, United KingdomOn June 19, 2011, at 1420 universal coordinated time (UTC), a McDonnell Douglas Helicopter Company model 369E, United Kingdom registration G-KSWI, s/n 0204E, was substantially damaged during an emergency landing after experiencing a mechanical failure of the…Jun 19, 2011 · G-KSWI · Substantial damageNTSB WPR09LA069Accident · 1 fatalLimited investigationFinal reportHughes 369 · Honiara, Solomon IslandsThe pilot's failure to remove the tail rotor pedal lock before attempting flight, resulting in a loss of control.Dec 28, 2008 · N104BN · Destroyed
See all 13 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\", '01046720'))
  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.