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NTSB investigations: Allison 250-C20 series, HI

24 cases on aircraft whose registry engine model is Allison 250-C20 series. 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

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Phase of flight

Aircraft model

Cases per year

19852026

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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."eventStateOrRegion" = 'HI' AND c."eventCountry" = 'USA' AND c."mKey" IN (SELECT x.case_mkey FROM 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' x WHERE x.engine_model_code IN ('03020')) 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.\"eventStateOrRegion\" = 'HI' AND c.\"eventCountry\" = 'USA'
    AND c.\"mKey\" IN (SELECT x.case_mkey FROM 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' x WHERE x.engine_model_code IN ('03020'))
  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."eventStateOrRegion" = 'HI' AND c."eventCountry" = 'USA'
  AND c."mKey" IN (SELECT x.case_mkey FROM 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' x WHERE x.engine_model_code IN ('03020'))
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 ANC24LA012Accident · No injuriesClass 4 · LimitedFinal reportMcdonnell Douglas Helicopter 369E · Waialua, HIThe pilot's inability to maintain directional control after a skid got caught on a fence while he was maneuvering the helicopter for takeoff, which resulted in a dynamic roll-over.Jan 25, 2024 · N545PH · Substantial damage 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…Feb 21, 2019 · N506PH · Substantial damage 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.Mar 3, 2012 · N101MZ · Substantial damage NTSB SEA08FA071Accident · Minor injuriesField investigationFinal reportMcdonnell Douglas 369E · Hilo, HIA leak in the fuel filter pressure differential switch that resulted in a loss of engine power. Contributing to the accident was uneven terrain that hindered a successful emergency landing.Feb 8, 2008 · N698DM · Substantial damage NTSB SEA07LA108Accident · Minor injuriesLimited investigationFinal reportHughes 369D · Kahuku, HIFatigue cracking of the oil line from the engine gearbox to the oil pressure gauge, which resulted in loss of engine lubricating oil, leading to seizure of the power turbine.Apr 20, 2007 · N911FT · Substantial damage NTSB LAX06TA259Accident · No injuriesFinal reportHughes 369D · Lahaina, HIthe pilot's failure to shut down the engine prior to exiting the helicopter resulting in the tail rotor contacting the ground. A contributing factor was the gusting wind conditions present at the accident site.Aug 13, 2006 · N114HD · Substantial damage NTSB LAX04CA315Accident · Minor injuriesData collectionFinal reportBell 206B · Kahului, HIthe pilot's inadequate compensation for the gusty crosswind conditions, which resulted in a dynamic rollover. Contributing factors were the direct crosswind and his lack of total experience in the accident helicopter make and model.Aug 16, 2004 · N529RS · Substantial damage NTSB LAX04LA116Accident · No injuriesLimited investigationFinal reportHughes 369D · Wahiawa, HIThe pilot's failure to properly secure the external sling load, which allowed the load to shift, and subsequently strike and remove the tail rotor.Dec 18, 2003 · N1113L · Substantial damage NTSB LAX03LA017Accident · Serious injuriesLimited investigationFinal reportHughes 369D · Kaaawa, Oahu, HIDynamic rollover during an attempted takeoff, due to the combined effects of the soft sloping terrain and the pilot's failure to redistribute the passengers to a more favorable lateral CG condition.Oct 29, 2002 · N220AL · Destroyed NTSB LAX01FA306Accident · Minor injuriesField investigationFinal reportBell 206B · Hilo, HIThe failure of the mechanic to secure the No. 8 bearing thrust nut during maintenance work, which resulted in the total failure of the first stage turbine wheel shaft. Also causal was his misjudgment of his height during the flare resulting in a hard landing.…Sep 30, 2001 · N206KS · Destroyed NTSB LAX00MA273Accident · 7 fatalMajor investigationFinal reportAerospatiale AS 355F1 · Kahului, Maui, HIThe pilot's inadequate decision by which he continued visual flight rules flight into instrument meteorological conditions. Also causal was his failure to maintain terrain clearance resulting in a collision with mountainous terrain. A contributing factor was…Jul 21, 2000 · N510TG · Destroyed NTSB LAX96LA104Accident · No injuriesLimited investigationFinal reportBell 206BIII · Kamuela, HIfailure of the nose case (No.1) bearing resulting in oil starvation.Feb 1, 1996 · N90194 · Substantial damage NTSB LAX94LA352Accident · Minor injuriesLimited investigationFinal reportHughes 369E · Volcano, HIthe pilot's failure to maintain adequate main rotor rpm and the resultant inadvertent skid contact with the ground.Sep 4, 1994 · N279F · Substantial damage NTSB LAX94LA241Accident · No injuriesLimited investigationFinal reportHughes 369D · Kaneohe, HIthe operator's and pilot's failure to ensure that the cargo net containing empty paper bags was sufficiently ballasted to prevent it from flying up into the tail rotor.Jun 7, 1994 · N4943T · Substantial damage NTSB LAX93LA249Accident · No injuriesLimited investigationFinal reportHughes 369D · Kahului, HIThe failure of the pilot to maintain adequate ground obstruction clearance while engaged in a cattle herding operation.Jun 11, 1993 · N1113L · Substantial damage NTSB LAX93LA132Accident · Serious injuriesLimited investigationFinal reportHughes 369D · Kahului, HIThe pilots failure to maintain an adequate visual lookout for obstructions while performing a low altitude surveillance operation in a mountainous area, and, his failure to select an altitude sufficient to ensure clearance from all potential obstacles.Feb 22, 1993 · N58240 · Substantial damage NTSB LAX91LA058Accident · Minor injuriesLimited investigationFinal reportMcdonnell Douglas 369D · Keanae, HIFuel starvation caused by a loose fuel line 'b' nut, due to improper maintenance; and the failure of the pilot to correctly judge the landing flare during the autorotation.Dec 18, 1990 · N58240 · Substantial damage NTSB LAX91LA054Accident · 1 fatalLimited investigationFinal reportMcdonnell Douglas 369D · Haleakla Nat Pk, HIFuel starvation due to the unporting of the fuel supply pick-up.Dec 9, 1990 · N1113L · Substantial damage NTSB LAX88LA179Accident · Serious injuriesLimited investigationFinal reportMcDonnell Douglas 369D · Waialua, HIFailure to follow procedures established by the manufacture for uncommanded trim inputs and his decision to make a hover approach to landing.May 13, 1988 · N4943T · Destroyed NTSB LAX88LA136Accident · No injuriesLimited investigationFinal reportBell 206B · Honolulu, HIAfter touchdown the plt reduced the throttle and removed his left hand from the throttle/collective pitch control to retune the radio. His attention was directed to the frequency indicator during the procedure. The helicopter became airborne and moved to the…Mar 18, 1988 · N2995W · Substantial damage NTSB LAX88LA043Accident · No injuriesLimited investigationFinal reportHughes 369D · Honolulu, HIThe plt rprtd that during an external load operation, the helicopter ran out of fuel. Subsequently, it was damaged when it touched down hard during a forced landing.Nov 14, 1987 · N1113L · Substantial damage NTSB LAX87LA310Accident · Minor injuriesLimited investigationFinal reportBell 206B · Kailua-Kona, HIAs the helicopter was climbing over rising terrain at 300' to 400' AGL, the plt noted altimeter & airspeed indcns of 8700' & 60 mph. After climbing an adnl 2 min to aprx 10,000' (12,000' density alt), he noticed the rotor RPM was bleeding off. He made a 180…Aug 23, 1987 · N2777R · Substantial damage NTSB LAX86LA091Accident · Minor injuriesLimited investigationFinal reportBell 206B-3 · Waimea, HIWhile on a local flt, the plt descended to aprx 500 ft AGL and flew the helicopter along a coastal area. He reported the helicopter suddenly lost power and he initiated an autorotative landing to the beach where the helicopter 'had a hard landing.' An exam…Jan 16, 1986 · N3179X · Substantial damage NTSB LAX85LA282Accident · No injuriesLimited investigationFinal reportBell 206B-III · Lahaina, HIThe pilot reported that the engine failed at an altitude of 800 feet MSL during the climb to cruise phase of a sightseeing flight with 3 passengers on board. The acft landed in the surf of the pacific ocean and damaged the tail rotor. The pilot and passengers…Jun 15, 1985 · N3179X · Substantial damage