NTSB investigations: Allison 250-C20 series

6 cases on aircraft whose registry engine model is Allison 250-C20 series, where the defining event was Loss of tail rotor effectiveness. Aircraft are matched to the registry by N-number and event date, checked against the reported serial number, make and model, so older matches can be wrong.

Cases per year

20082026
NTSB investigations: Allison 250-C20 series per year, 2008–2026: 6 cases
20081
20151
20171
20201
20211
20221

Latest 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 x.case_mkey FROM 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' x WHERE x.engine_model_code IN ('03020')
      AND EXISTS (SELECT 1 FROM 'https://openairdocs.org/data/latest/ntsb_events.parquet' e WHERE e.case_mkey = x.case_mkey AND e.aircrafts_position = x.position AND e.\"isDefiningEvent\" AND e.\"tier2Number\" = '242'))
  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.

NTSB WPR22FA101Accident · 1 fatalClass 3 · FieldFinal reportMcdonnell Douglas 500N · Newport Beach, CAThe helicopter’s encounter with unanticipated right yaw during a low-altitude, low-airspeed, tight-radius orbit. Contributing to the accident was the pilot’s distraction during the orbit, which resulted in the loss of control, his fatigue due to his early…Feb 20, 2022 · N521HB · Substantial damageNTSB CEN22FA086Accident · 2 fatalClass 3 · FieldFinal reportBell 206B · Livingston, TXThe pilot exceeding the yaw control capability of the helicopter for the flight conditions, resulting in a non-mechanical loss of tail rotor effectiveness.Dec 30, 2021 · N8AU · Substantial damageNTSB CEN20LA273Accident · Serious injuriesClass 3 · LimitedFinal reportAerospatiale AS355 · Rifle, COA loss of tail rotor effectiveness, the pilot’s subsequent loss of helicopter control, and collision with terrain.Jul 11, 2020 · N708AC · DestroyedNTSB GAA17CA369Accident · No injuriesData collectionFinal reportBell 206B · Entiat, WAThe pilot’s failure to secure a loose item inside the cockpit that interfered with antitorque pedal control and led to a loss of helicopter control due to a loss of tail rotor effectiveness.Jun 26, 2017 · N183TC · Substantial damageNTSB GAA15CA102Accident · No injuriesData collectionFinal reportBell 206 - B11 · Caledonia, MIA loss of tail rotor effectiveness while maneuvering at low altitude, resulting in a collision with trees.May 29, 2015 · N206ED · Substantial damageNTSB SEA08LA213Accident · Serious injuriesLimited investigationFinal reportBell 206B · Woods Landing-Jelm, WYThe pilot's encounter with a loss of tail rotor effectiveness event and his failure to maintain directional control while maneuvering. Contributing to the accident were the tailwind condition and the sloping, uneven terrain.Sep 27, 2008 · N59611 · Substantial damage