NTSB investigations: Allison 250-C20 series
372 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.
Cases, newest first
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'))
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'))
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 DEN02LA013Accident · Serious injuriesLimited investigationFinal reportBell 206B · Bryce, UTloss of engine power for reasons undetermined. Contributing factors were the low airspeed and altitude at which to perform an autorotation.NTSB SEA02FA008Accident · 3 fatalField investigationFinal reportBell 206L · Anchorage, AKThe pilot's failure to maintain clearance from the surface of an open body of water while intentionally attempting to maintain a very low altitude while in cruise flight. Factors include falling snow, low ceilings, whiteout/greyout conditions, and flat/glassy…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.…NTSB CHI01LA327Accident · Minor injuriesLimited investigationFinal reportBell 206B-III · Park Rapids, MNThe pilot not maintaining altitude/clearance when he maneuvered above the glassy lake. A factor to the accident was the glassy lake condition.NTSB LAX01LA305Accident · No injuriesLimited investigationFinal reportHughes 369D · Carlsbad, CAA hard landing due to the dual student's failure to maintain main rotor speed, his improper landing flare, and the flight control interference by the flight instructor.NTSB MIA01TA194Accident · Minor injuriesFinal reportBell 206B-III · Jacksonville, FLthe pilot's failure to recognize and correct for unanticipated right yaw/loss of tail rotor effectiveness (LTE) during an approach to hover at a low altitude, which resulted in a loss of control and the helicopter descending and colliding with a house and the…NTSB LAX01IA262Incident · No injuriesIncident investigationFinal reportMdhi 520N · Los Angeles, CAthe excitation of the first bending mode natural frequency of the aft tube assembly that is installed through the rotating NOTAR fan drive system. Contributing factors to the incident included the operator's maintenance practice of hand-sanding the pitch…NTSB NYC01LA179Accident · No injuriesLimited investigationFinal reportMcDonnell Douglas 369E · Niagara Falls, NYThe right skid getting snagged on the helicopter-dolly resulting in dynamic rollover.NTSB SEA01LA082Accident · No injuriesLimited investigationFinal reportSchweizer 269D · Nampa, IDthe pilot's inadequate compensation for strong, gusty, shifting winds while hovering in ground effect. Factors include a sudden directional change and increase in velocity of the gusty wind conditions.NTSB IAD01TA051Accident · Minor injuriesFinal reportHughes 369D · Taylorsville, KYthe flight instructor's inadequate aircraft control during a practice autorotation which resulted in a hard landing.NTSB CHI01LA119Accident · Minor injuriesLimited investigationFinal reportHughes 369D · Du Quoin, ILloss of engine power for undetermined reasons, the pilot operating the helicopter outside of the height-velocity curve, and the pilot's failure to maintain control of the helicopter during the emergency landing. Factors relating to the accident were the…NTSB SEA01LA024Accident · No injuriesLimited investigationFinal reportBell 206 B3 · Lake Kachess, WAThe pilot's failure to comply with the flight manual regarding the use of an induction system deflector kit (snow baffles) while operating in snow, and the ingestion of foreign material/snow that resulted in an engine flameout while hovering. A snow baffle…NTSB MIA01FA006Accident · 1 fatalField investigationFinal reportAerospatiale AS-355-F2 · Burlington, NCThe mechanics failure to comply with manufacturers instructions for correction of a illuminated main rotor gearbox oil pressure warning light resulting in the helicopter being dispatched on a ferry flight with a failed main rotor gearbox oil pump, failure of…NTSB LAX01FA006Accident · Minor injuriesField investigationFinal reportMcDonnell Douglas 369E · Kernville, CAThe pilot's improper storage of personal items and his inadequate preflight inspection, which resulted in the unlatching of the left rear cabin door during flight and allowing a plastic garment bag to blow out and strike the tail rotor.NTSB SEA00LA197Accident · No injuriesLimited investigationFinal reportBell 206BII · Newhalem, WADebonding between the elastomeric material and the center plate of the transmission isolation mount.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…NTSB FTW00LA181Accident · Minor injuriesLimited investigationFinal reportBell 206B · Deville, LAthe pilot's failure to maintain clearance with the external load that was setting on the ground while hovering. A contributing factor was the pilot's diverted attention.NTSB LAX00TA186Accident · No injuriesFinal reportMcDonnell Douglas 500N · Los Angeles, CAThe combined failure of the operator management and the check pilot to ensure the landing area was suitable for the slide on landing. Factors were the high vegetation that entangled the skids, resulting in the abrupt stop and nose down movement of the…NTSB DEN00FA082Accident · 2 fatalField investigationFinal reportMcDonnell Douglas 369E · Bloomfield, NMThe pilot's intentional buzzing (low level flying), and his failure to maintain clearance with the static wire. A factor was his physical impairment by a contraindicated drug controlled substance.NTSB CHI00LA121Accident · No injuriesLimited investigationFinal reportHughes 500C · Salina, KSthe loss of tail rotor effectiveness and the autorotation performed by the pilot. The unfavorable wind was a contributing factor.NTSB LAX00LA156Accident · No injuriesLimited investigationFinal reportBell 407 · Grand Canyon, AZThe failure and subsequent disintegration of the oil cooler fan forward hanger bearing.NTSB FTW00FA091Accident · 4 fatalField investigationFinal reportEurocopter BO105S-CBS-5 · Dalhart, TXThe pilot's failure to maintain control of the helicopter as a result of his continued flight into known adverse weather conditions. Factors were the dark night light condition, fog, low ceiling, and the pilot's lack of total instrument flight time.NTSB LAX00LA109Accident · Minor injuriesLimited investigationFinal reportHughes 500C · Pohnpei (Pacific Ocean)The pilot reported that he and the observer were planning to conduct tuna spotting operations. This was to be the first flight of the day. After takeoff, about 100 to 150 feet above sea level, the helicopter began an uncommanded right turn, followed by an…NTSB IAD00LA015Accident · No injuriesLimited investigationFinal reportBell 206A · Brutus, NYWas the pilot's failure to maintain directional control after encountering a loss of tail rotor effectiveness.NTSB LAX00LA047Accident · No injuriesLimited investigationFinal reportBoeing 369E · Taft, CAThe fatigue failure of a second stage compressor vane due to erosion, which resulted in a catastrophic engine failure. An inadequate inspection of the compressor section by company maintenance personnel during the last 300-hour inspection was also causal in…NTSB SEA00FA021Accident · Minor injuriesField investigationFinal reportBell 206L-3 · Seattle, WAAdequate separation and lookout not maintained by the pilots of both aircraft.NTSB CHI00FA020Accident · 2 fatalField investigationFinal reportBell 206B · Cottage Grove, MNUndetermined.NTSB LAX00GA025Accident · 2 fatalFinal reportMcDonnell Douglas 500N · San Jose, CAThe pilot's in-flight loss of control due to the failure and separation of the forward thruster control cable telescoping sleeve ball swivel fitting, which resulted in a stuck thruster and the entry into an uncontrollable yaw/spin. Also causal was the…NTSB LAX00LA016Accident · Minor injuriesLimited investigationFinal reportBell 206-B3 · Soda Springs, CAThe failure of the pilot-in-command to maintain landing skid clearance during hover taxi, which resulted in a dynamic rollover.NTSB LAX99LA292Accident · 2 fatalLimited investigationFinal reportHughes 369HS · Pohnpei (Pacific Ocean)An in-flight collision with the water for undetermined reasons.NTSB LAX99LA237Accident · No injuriesLimited investigationFinal reportHiller UH-12ET · Williams, CAThe pilot's inadequate preflight planning and verification that fuel was available for the intended flight. A factor was the fuel quantity false indication.NTSB NYC99LA147Accident · Minor injuriesLimited investigationFinal reportBell 206B-III · Tinicum, PAThe pilot's failure to maintain a proper altitude above the water.NTSB LAX99LA253Accident · Minor injuriesLimited investigationFinal reportHughes 369HS · Pacific Ocean (Pacific Ocean)The removal of the tail rotor blade abrasion strips by the use of an unapproved method by the maintenance personnel which resulted in the imbalance of the tail rotor blade assembly and subsequent separation of the 90-degree gear box; the pilot/mechanic's…NTSB MIA99FA158Accident · 1 fatalField investigationFinal reportHughes 369E · Intercession, FLThe pilot's improper fuel management that resulted in fuel exhaustion and a total loss of engine power.NTSB LAX99FA136Accident · 1 fatalField investigationFinal reportBell 206B · Grand Canyon, AZThe failure of the flight crew to properly preflight the helicopter and to detect and remove accumulated snow from the engine inlets and plenum chamber. Factors in the accident were the clouded plenum chamber inspection window and the failure of preceding…NTSB MIA99LA111Accident · No injuriesLimited investigationFinal reportFairchild Hiller FH-1100 · Zephyrhills, FLThe student pilot's improper use of flight controls (cyclic and collective) during a takeoff to a hover. This resulted in the helicopter encountering dynamic rollover and rolling over on its right side.NTSB LAX99LA116Accident · Minor injuriesLimited investigationFinal reportBell 206B · Delhi, CAThe pilot's failure to maintain clearance while landing in proximity to high vegetation, which resulted in the inadvertent contact of the spray boom to the trees.NTSB SEA99FA037Accident · No injuriesField investigationFinal reportHiller UH-12E · Yellow Pine, IDAltitude deviation during aerial taxi for undetermined reasons.NTSB FTW99LA076Accident · Minor injuriesLimited investigationFinal reportBell 206-B3 · Sabine Pass, TXThe pilot's inadvertent flight into instrument meteorological conditions and subsequent spatial disorientation. Factors were the dark night conditions, the fog, and the pilot's failure to obtain a weather briefing prior to the flight.NTSB DEN99TA031Accident · No injuriesFinal reportHughes 369D · Woodruff, UTA partial loss of engine power due to erosion in the compressor assembly module. Factors were a missing rotating labyrinth seal, the installation of which had not been performed by unknown maintenance personnel.NTSB CHI98TA354Accident · No injuriesFinal reportBell 206B-3 · Hinkley, MNLoss of engine power due to failure of the engine governor.NTSB LAX98LA200Accident · 2 fatalLimited investigationFinal reportHughes 369HS · Pacific Ocean (Pacific Ocean)The improper shimmying of the tail rotor driveshaft by maintenance personnel which induced fatigue in the tail rotor driveshaft coupling causing it to fail, which resulted in a loss of tail rotor control. A factor is the failure of the pilot to recognize the…NTSB FTW98LA235Accident · No injuriesLimited investigationFinal reportBell 206BIII · Hurst, TXThe pilot's delayed recovery from a simulated autorotative landing.NTSB LAX98TA123Accident · No injuriesFinal reportBell 206B · Santa Clarita, CAThe failure of the pilot to maintain adequate clearance with the wires. Additional factors in this accident are the position of the sun at that time of the day, which made it difficult to see the wires, and the lack of markings or poles for that series of…NTSB SEA98LA024Accident · No injuriesLimited investigationFinal reportBell 206L · Idaho Falls, IDloss of engine power for undetermined reason(s). A factor relating to the accident included a dirt berm/ridge in the field where the pilot executed the forced landing.NTSB FTW97FA352Accident · Minor injuriesField investigationFinal reportBell 407 · Grand Isle S108The tail rotor blade strike(s) that severed the aft portion of the tailboom, subsequently rendering the pilot with no tail rotor control while in cruise flight. A factor was the lack of suitable terrain for the forced autorotative landing.NTSB ANC97GA126Accident · 1 fatalFinal reportBell BH-206B · Dillingham, AKThe pilot's intentional VFR flight into instrument meteorological conditions (IMC). Factors associated with the accident are the pilot's failure to activate the cabin heating system, the lack of an operable windshield defogger, the pilot's overconfidence in…NTSB FTW97LA252Accident · Serious injuriesLimited investigationFinal reportBell 206B · New Iberia, LAthe pilot's improper in-flight planning/decision. A related factor was his failure to follow the company procedure of maintaining visual contact with the external long-line cable, while hovering with it attached.NTSB ATL97LA086Accident · Serious injuriesLimited investigationFinal reportMcDonnell Douglas MDHC-369E · Okahumpka, FLThe failure of the crewmember to use the necessary safety equipment, and his subsequent fall from an elevated platform. A factor was the crewmember's distraction with an animal.NTSB SEA97LA072Accident · Minor injuriesLimited investigationFinal reportHiller UH-12E · Glide, ORfailure of the pilot to maintain clearance from a power transmission line. Factors relating to the accident included ambient light conditions, which made the power line hard to see.