NTSB investigations: Allison 250 SER 400HP

8 cases on aircraft whose registry engine model is Allison 250 SER 400HP, where the first occurrence was “Loss of engine power”. 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

19822026

NTSB investigations: Allison 250 SER 400HP per year, 1982–2026: 8 cases
1982	1
1987	1
1988	1
1991	1
1997	2
1998	1
1999	1

Where

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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 ('03013', '03012') 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" = 350)) 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 ('03013', '03012')
      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\" = 350))
  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 ('03013', '03012')
    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" = 350))
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 SEA99LA082Accident · Minor injuriesLimited investigationFinal reportHughes 369D · Southbend, WAThe complete loss of power, due to a failure of the compressor impeller disk. Factors include the low altitude of the helicopter at the time of the power loss, and the need to autorotate in a confined area.Jun 8, 1999 · N8306F · Substantial damage NTSB FTW98LA187Accident · No injuriesLimited investigationFinal reportBell 206B · Cameron, LAThe loss of engine power for undetermined reasons and the pilot's improper flare which resulted in a hard landing.Apr 17, 1998 · N59604 · Substantial damage NTSB IAD98FA005Accident · 4 fatalField investigationFinal reportBell 206B · Sago, WVThe improper overhaul of the turbine governor by the manufacturer, which resulted in the loss of power.Oct 12, 1997 · N911RH · Destroyed NTSB SEA97LA118Accident · No injuriesLimited investigationFinal reportHughes 369D · Moclips, WAInadequate installation of the fuel control by company maintenance personnel and a loose nut on a line. A disconnected Pc line was a factor.May 21, 1997 · N8306F · Substantial damage NTSB LAX91LA198Accident · Minor injuriesLimited investigationFinal reportHughes 369HS · Keanae, HIThe total failure in fatigue of the helicopter's spur adapter gearshaft. A contributing factor was related to the lack of a suitable emergency landing site.May 5, 1991 · N9219F · Substantial damage NTSB FTW88LA153Accident · No injuriesLimited investigationFinal reportBell 206B · Pearland, TXThe helicopter was at 300 feet AGL, making an approach after a maintenance test flight, when the engine overtemped and engine power was lost. During the autorotation landing, the helicopter touched down hard. The acft eng began to decelerate prior to…Aug 18, 1988 · N16962 · Substantial damage NTSB LAX87LA161Accident · 1 fatalLimited investigationFinal reportBell 206B · Kona, HIThe pilot picked up two of the passengers at a resort hotel and then flew to kailua-Kona airport (koa). After hot refueling the helicopter with the two passengers on board, two more passengers boarded the helicopter and then the flight departed koa. When the…Mar 29, 1987 · N90153 · Destroyed NTSB ANC82DA039Accident · No injuriesFinal reportHughes 369HS · Tok, AKThe pilot was conducting a non-revenue, sling-load operation on mt neuberer, while donating his services to Tok community tv, inc. he stated that he was lifting three empty propane bottles from a snow field when he noticed the auto relight lamp flash. He…May 4, 1982 · N9239F · Substantial damage