NTSB investigations: Allison 250 series

6 cases on aircraft whose registry engine model is Allison 250 series, where the first occurrence was “Airframe/component/system failure/malfunction”. 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.

Defining event

Finding

Phase of flight

Aircraft model

Cases per year

19862026

NTSB investigations: Allison 250 series per year, 1986–2026: 6 cases
1986	1
1991	1
1993	2
1994	1
2007	1

Where

Open the map

Latest cases

Query with SQL

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 ('03014', '03019') AND EXISTS (SELECT 1 FROM 'https://openairdocs.org/data/latest/ntsb_occurrences.parquet' o WHERE o.case_mkey = x.case_mkey AND o.aircrafts_position = x.position AND o."occurrenceNumber" = 1 AND o."occurrenceCode" = 130)) ORDER BY c."eventDate" DESC, c."ntsbNumber" DESC

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 ('03014', '03019')
      AND EXISTS (SELECT 1 FROM 'https://openairdocs.org/data/latest/ntsb_occurrences.parquet' o WHERE o.case_mkey = x.case_mkey AND o.aircrafts_position = x.position AND o.\"occurrenceNumber\" = 1 AND o.\"occurrenceCode\" = 130))
  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.

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 ('03014', '03019')
    AND EXISTS (SELECT 1 FROM 'https://openairdocs.org/data/latest/ntsb_occurrences.parquet' o WHERE o.case_mkey = x.case_mkey AND o.aircrafts_position = x.position AND o."occurrenceNumber" = 1 AND o."occurrenceCode" = 130))
ORDER BY c."eventDate" DESC, c."ntsbNumber" DESC

Run it at the DuckDB prompt, or in any tool that reads Parquet over HTTPS. More ways to query the release are on Use the data.

NTSB CHI07LA277Accident · Minor injuriesLimited investigationFinal reportBell 47G-5A · Anoka, MNThe loss of helicopter pitch control for undetermined reasons during the aerial application maneuver and the pilot's inability to control the aircraft during the descent.. A contributing factor to the accident was the soft terrain.Aug 24, 2007 · N25LB · Substantial damage NTSB SEA94LA149Accident · Minor injuriesLimited investigationFinal reportHiller-Soloy UH-12L4 · Clarkston, WADisconnection of the ballast bar aft retaining pin. Factor(s) were: tail rotor blade separation and reduced aircraft control.Jun 14, 1994 · N67264 · Substantial damage NTSB LAX94LA054Accident · Minor injuriesLimited investigationFinal reportHiller UH-12E · Salinas, CAa fatigue failure of the torsion-tension bar pin due to fretting corrosion. A factor in this accident was an inadequate quality of material utilized in the manufacture of the pin.Nov 20, 1993 · N161HA · Substantial damage NTSB SEA94LA029Accident · No injuriesLimited investigationFinal reportBell 47G3B2 · Toledo, WATransmission shear bolts failed causing a loss of power to the rotor system, and the pilot encountered unsuitable terrain during his autorotation attempt.Nov 9, 1993 · N8169J · Substantial damage NTSB MIA92LA014Accident · No injuriesLimited investigationFinal reportBell 47G-5 · La Belle, FLThe pilot in command's improper aft application of cyclic control during an autorotative landing to an open field, resulting in the main rotor blades colliding with the tail boom. Contributing to the accident was the in flight failure of the outer bearing of…Oct 13, 1991 · N1201W · Substantial damage NTSB SEA86FA039Accident · 1 fatalField investigationFinal reportHiller-Soloy UH-12E · Horton, ORThe fork connecting the rotorcraft's blue blade to the main rotor hub separated after a long term fatigue crack had spread through more than 60% of the fork circumference. The operator failed to carry out the appropriate inspection of the fork unit as…Jan 16, 1986 · N40290 · Destroyed