NTSB investigations: Allison 250-C20 series
8 cases on aircraft whose registry engine model is Allison 250-C20 series, where the defining event was Loss of engine power (partial). 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
| 2012 | 1 |
|---|---|
| 2014 | 1 |
| 2018 | 1 |
| 2019 | 1 |
| 2022 | 2 |
| 2023 | 1 |
| 2026 | 1 |
Where
Open the mapLatest 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\" = '342'))
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 ('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" = '342'))
ORDER BY c."eventDate" DESC, c."ntsbNumber" DESCRun 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 WPR26LA347Accident · No injuriesClass 3 · LimitedPreliminary reportBell 206B-III · Creswell, NCOn September 18, 2026, at 1018 eastern daylight time, a Bell 206B-III, N50141, was substantially damaged when it was involved in an accident near Creswell, North Carolina. The pilot was not injured. The helicopter was being operated as a Title 14 Code of…NTSB WPR23LA278Accident · No injuriesClass 3 · LimitedFinal reportAerospatiale AS-355E Twin Star · Farmington, UTThe premature failure of one of the No. 2 engine compressor bleed valve, which resulted in a partial loss of power to that engine.NTSB CEN22LA146Accident · Minor injuriesClass 3 · LimitedFinal reportHughes 369 · Adair, IAThe mechanic’s failure to properly torque a fuel control unit B-nut, which resulted in a partial loss of engine power, an attempted autorotation, and an impact with terrain.NTSB ERA22LA117Accident · No injuriesClass 3 · LimitedFinal reportHughes 369D · Bel Air, MDA loss of engine power due to bearing failures in the turbine section resulting from a fatigue fracture of the oil supply line that fed oil to the Nos. 6 and 7 bearings. The oil line failure led to rapid deterioration of the bearings from oil starvation.…NTSB WPR19LA087Accident · Serious injuriesClass 3 · LimitedFinal reportMD Helicopter 369 · Kukuihaele, HIThe partial loss of engine power due to corrosion in the engine bleed valve due to wash solution intrusion. Contributing to the accident was the installation of a bushing manufactured to incorrect dimensions in the bleed valve, and the uneven terrain at the…NTSB WPR18LA164Accident · Minor injuriesClass 3 · LimitedFinal reportBell 206 · Sanders, KYA partial loss of engine power for undetermined reasons, and a loss of main rotor rpm during the subsequent autorotation, which resulted in a hard landing.NTSB CEN14IA270Incident · No injuriesIncident investigationFinal reportBell 407 · Eugene Island 182AThe improper repair of the outer combustion case, which led to its ultimate failure due to the continued progression of a fatigue crack and resulted in a partial loss of engine power during takeoff.NTSB WPR12LA125Accident · No injuriesLimited investigationFinal reportAerospatiale AS 355F1 · Makakilo City, HIA partial loss of engine power while maneuvering over rough/uneven terrain that was precipitated by the failure of a 3rd stage turbine blade as a result of high-cycle fatigue.