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Settling with power/vortex ring state

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NTSB defining event · CICTT: Loss Of Control (Inflight)

CICTT occurrence categories (PDF)CICTT phases of flight (PDF)

All 42 cases52 anywhere in the sequence
Defining event in
42 cases
In the sequence of
52 cases
Fatal cases
2
NTSB code
244

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 it was the defining event; in gray, cases where it came elsewhere in the sequence. The map shows the cases where it was the defining event. Events are coded with the final report, so the latest years are incomplete.

Cases per year

2008Defining eventElsewhere in the sequence2026

Where

Open the map
Query with SQL
duckdb -csv -c "SELECT year(c.\"eventDate\") AS year, count(DISTINCT e.case_mkey) AS cases,
    count(DISTINCT e.case_mkey) FILTER (WHERE e.\"isDefiningEvent\") AS defining
  FROM 'https://openairdocs.org/data/latest/ntsb_events.parquet' e JOIN 'https://openairdocs.org/data/latest/ntsb_case_detail.parquet' c ON c.\"mKey\" = e.case_mkey
  WHERE e.\"tier2Number\" = '244' AND e.case_mkey IN (SELECT case_mkey FROM 'https://openairdocs.org/data/latest/ntsb_events.parquet' WHERE \"isDefiningEvent\")
  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 these cases

Phase of flight
  • Maneuvering-low-alt flying12
  • Approach6
  • Maneuvering-hover6
  • Landing5
  • Takeoff5
  • Maneuvering4
  • Landing-flare/touchdown2
  • Approach-VFR pattern final1
  • Initial climb1
In the probable cause
Aircraft models

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

Query with SQL
duckdb -csv -c "WITH defining AS (SELECT * FROM 'https://openairdocs.org/data/latest/ntsb_events.parquet' WHERE \"tier2Number\" = '244' AND \"isDefiningEvent\")
  SELECT * FROM (
  SELECT 'Phase of flight' AS kind, e.\"tier1Number\" AS code, max(e.\"eventTier1Name\") AS name, count(DISTINCT e.case_mkey) AS cases
  FROM defining e
  GROUP BY ALL
  UNION ALL
  SELECT 'Finding in the probable cause', left(f.\"findingCode\", 8), max(f.\"tier4Name\"), count(DISTINCT f.case_mkey)
  FROM defining e JOIN 'https://openairdocs.org/data/latest/ntsb_findings.parquet' f ON f.case_mkey = e.case_mkey AND f.aircrafts_position = e.aircrafts_position AND f.\"inProbableCause\"
  WHERE f.\"findingCode\" GLOB '[0-9][0-9]*'
  GROUP BY ALL
  UNION ALL
  SELECT 'Aircraft model', a.aircraft_model_code, any_value(concat_ws(' ', m.manufacturer, m.model)), count(DISTINCT e.case_mkey)
  FROM defining e JOIN 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' a ON a.case_mkey = e.case_mkey AND a.position = e.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
  )
  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 · 42

NTSB ANC25LA099Accident · No injuriesClass 4 · LimitedFinal reportRobinson Helicopter R44 II · Petersville, AKThe pilot’s exceedance of the helicopter’s available power while landing in a remote confined area, which resulted in rotor droop and a hard landing.Aug 29, 2025 · N74435 · Substantial damageNTSB ERA24LA327Accident · No injuriesClass 4 · LimitedFinal reportEnstrom 280FX · Russellville, KYThe flight instructor’s failure to maintain sufficient rotor rpm while maneuvering the helicopter low to the ground, which resulted in a loss of control.Jul 27, 2024 · N280D · Substantial damageNTSB ERA24LA287Accident · No injuriesClass 4 · LimitedFinal reportAirbus Helicopters AS350 · Sanford, FLThe helicopter pilot’s improper maneuvering at low altitude in gusty wind conditions, which resulted in the helicopter entering a vortex ring state, and hard landing during a subsequent autorotation.Jun 27, 2024 · N174SC · Substantial damageNTSB WPR23LA061Accident · Minor injuriesClass 4 · LimitedFinal reportEurocopter EC 130 B4 · Waimea, HIThe pilot's loss of helicopter control on approach to land due to entering a vortex ring state condition, which resulted in a hard landing.Dec 8, 2022 · N130WS · Substantial damageNTSB CEN22LA033Accident · No injuriesClass 4 · LimitedFinal reportRobinson Helicopter R22 Beta · Freer, TXThe pilot’s encounter with ‘settling with power’ while maneuvering at a low altitude, which resulted in a rapid descent and subsequent hard landing.Nov 10, 2021 · N7198A · Substantial damageNTSB WPR21LA236Accident · No injuriesClass 4 · LimitedFinal reportBell UH-1H · Townsend, MTThe pilot’s failure to maintain helicopter control after an encounter with settling with power during approach at an altitude that was too low for recovery, which resulted in a hard landing.Jun 15, 2021 · N398M · DestroyedNTSB ERA21LA040Accident · No injuriesClass 4 · LimitedFinal reportBell 206 · Raleigh, NCThe pilot's loss of helicopter control after entry into vortex ring state, which resulted in main rotor blade contact with the tailboom, and impact with the ground.Nov 8, 2020 · N123NC · Substantial damageNTSB ERA20LA273Accident · 1 fatalClass 3 · LimitedFinal reportEurocopter EC130 · Knoxville, TNThe pilot's entry into vortex ring state and his inability to arrest the helicopter's descent while maneuvering for landing.Aug 3, 2020 · N55GJ · Substantial damageNTSB GAA19CA345Accident · Serious injuriesData collectionFinal reportS M & T UH · Northway, AKThe pilot's failure to maintain a proper descent rate during landing, which resulted in impact with terrain.Jun 10, 2019 · N64771 · Substantial damageNTSB ERA19WA167Accident · No injuriesForeign investigationBell 206 · Sabanalarga, ColombiaThe government of Colombia has notified the NTSB of an accident involving a BELL 206 helicopter that occurred on April 30, 2019. The NTSB has appointed a U.S. Accredited Representative to assist the government of Colombia's investigation under the provisions…Apr 30, 2019 · HK3321 · Substantial damage
See all 42 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 e.case_mkey FROM 'https://openairdocs.org/data/latest/ntsb_events.parquet' e WHERE e.\"isDefiningEvent\" AND e.\"tier2Number\" = '244')
  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.