# NTSB investigations: Allison 250-C20 series: Airframe/component/system failure/malfunction NTSB aviation accident and incident investigations since 1962: the probable cause, findings, aircraft, crew, weather and docket of each, linked to the FAA registry and the FAA’s own reports. ## Latest cases - [NTSB NYC07LA188](https://openairdocs.org/ntsb/NYC07LA188.md): Bell 206B · Warrenton, VA · Accident · No injuries · Limited investigation · Final report · Aug 7, 2007 · N3202D · Substantial damage > The flight instructor's failure to maintain adequate rotor rpm during touchdown. - [NTSB MIA07FA098](https://openairdocs.org/ntsb/MIA07FA098.md): Hughes 369A · Moulton, AL · Accident · 1 fatal · Field investigation · Final report · May 13, 2007 · N468WE · Destroyed > The separation of a main rotor blade from its tension torsion bar for an undetermined reason. - [NTSB SEA06LA135](https://openairdocs.org/ntsb/SEA06LA135.md): Hughes 369D · Moab, UT · Accident · No injuries · Limited investigation · Final report · Jun 30, 2006 · N369PB · Substantial damage > The failure of the collective bungee support bracket due to non-compliance with a service information notice, which resulted in the pilot executing a precautionary autorotative landing. A contributing factor was the lack of suitable terrain for the landing. - [NTSB LAX06LA161](https://openairdocs.org/ntsb/LAX06LA161.md): Bell 206B3 · Fallbrook, CA · Accident · Minor injuries · Limited investigation · Final report · May 4, 2006 · N2763R · Substantial damage > Failure of the engine to transmission drive shaft forward coupling due to overheating from lack of lubrication. The cause of the lack of lubrication was a result of improper maintenance. A factor was the trees. - [NTSB ATL04LA181](https://openairdocs.org/ntsb/ATL04LA181.md): Hughes HU-369-D · Waynesboro, GA · Accident · Minor injuries · Limited investigation · Final report · Sep 10, 2004 · N5211R · Substantial damage > The tail rotor assembly failed due to a fatigue fracture of the input gearshaft in the tail rotor gearbox assembly, which resulted in a loss of tail rotor control and subsequent collision with trees. - [NTSB FTW03LA080](https://openairdocs.org/ntsb/FTW03LA080.md): Bell 206B · Putnam, TX · Accident · Serious injuries · Limited investigation · Final report · Jan 9, 2003 · N115TV · Substantial damage > the pilot's failure to properly interpret and confirm a faulty tachometer instrument indication and his improper flare during the ensuing precautionary autorotation, which resulted in a hard landing. Also causal was the failure of the tachometer. - [NTSB SEA02LA137](https://openairdocs.org/ntsb/SEA02LA137.md): Bell 206B · Elsie, OR · Accident · No injuries · Limited investigation · Final report · Jul 24, 2002 · N60PH · Substantial damage > The shattering and separation of the forward right (pilot's) windscreen for undetermined reason(s). - [NTSB LAX01IA262](https://openairdocs.org/ntsb/LAX01IA262.md): Mdhi 520N · Los Angeles, CA · Incident · No injuries · Incident investigation · Final report · Jul 25, 2001 · N953SD · Minor damage > the 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 MIA01FA006](https://openairdocs.org/ntsb/MIA01FA006.md): Aerospatiale AS-355-F2 · Burlington, NC · Accident · 1 fatal · Field investigation · Final report · Oct 17, 2000 · N355DU · Destroyed > The 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 LAX01FA006](https://openairdocs.org/ntsb/LAX01FA006.md): McDonnell Douglas 369E · Kernville, CA · Accident · Minor injuries · Field investigation · Final report · Oct 8, 2000 · N819CE · Substantial damage > The 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 SEA00LA197](https://openairdocs.org/ntsb/SEA00LA197.md): Bell 206BII · Newhalem, WA · Accident · No injuries · Limited investigation · Final report · Aug 24, 2000 · N90307 · Substantial damage > Debonding between the elastomeric material and the center plate of the transmission isolation mount. - [NTSB LAX00GA025](https://openairdocs.org/ntsb/LAX00GA025.md): McDonnell Douglas 500N · San Jose, CA · Accident · 2 fatal · Final report · Oct 25, 1999 · N904PD · Destroyed > The 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 LAX99LA253](https://openairdocs.org/ntsb/LAX99LA253.md): Hughes 369HS · Pacific Ocean (Pacific Ocean) · Accident · Minor injuries · Limited investigation · Final report · Jun 7, 1999 · N4278M · Destroyed > 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 FTW97FA352](https://openairdocs.org/ntsb/FTW97FA352.md): Bell 407 · Grand Isle S108 · Accident · Minor injuries · Field investigation · Final report · Sep 18, 1997 · N467PH · Substantial damage > The 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 FTW95IA397](https://openairdocs.org/ntsb/FTW95IA397.md): MBB BO-105C · Lafayette, LA · Incident · No injuries · Incident investigation · Final report · Sep 18, 1995 · N91070 · No damage > a short in the 'jam proof system' solenoid valve which prevented activation of the backup hydraulic system and resulting in a cyclic hardover. Factors were the contaminated hydraulic fluid and the resulting jammed actuator (longitudinal control slider). - [NTSB MIA94LA144](https://openairdocs.org/ntsb/MIA94LA144.md): Bell 206B · St. Petersburg, FL · Accident · Minor injuries · Limited investigation · Final report · May 19, 1994 · N72Z · Substantial damage > The failure of the number five bearing, shaft, or thomas coupling for undetermined reasons. Contributing to the accident was the pilot-in-command's delayed response in conducting the emergency procedure by not reducing the throttle to idle position, and… - [NTSB LAX93LA044](https://openairdocs.org/ntsb/LAX93LA044.md): Hughes 369D · Carlsbad, CA · Accident · No injuries · Limited investigation · Final report · Nov 16, 1992 · N220AL · Substantial damage > Failure of the overrunning clutch assembly bearing for undetermined reasons. - [NTSB LAX87FA173](https://openairdocs.org/ntsb/LAX87FA173.md): Hughes 369E · Palm Desert, CA · Accident · Serious injuries · Field investigation · Final report · Apr 11, 1987 · N5200W · Substantial damage > The helicopter dscndd uncontrolled & crashed in a residential area. After the acdnt, the plt said he agreed to orbit the residence of his pax. At the aprx 135 deg point of a left orbit, he felt 'a bang & severe vibration in the tail.' The plt lost drctnl ctl… - [NTSB NYC87LA058](https://openairdocs.org/ntsb/NYC87LA058.md): Agusta A109AII · So. Dartmouth, MA · Accident · Minor injuries · Limited investigation · Final report · Jan 13, 1987 · N300CC · Substantial damage > Agusta N300CC departed a helipad in front of claremont corp president's residence in south Dartmouth, Massachusetts. As the helicopter was hovering prior to moving forward, the tail rotor blade, s/n 124, failed. The tail rotor assembly and gearbox separated… - [NTSB LAX84FA405](https://openairdocs.org/ntsb/LAX84FA405.md): Hughes 369D · Mesa, AZ · Accident · 2 fatal · Field investigation · Final report · Jul 18, 1984 · N58369 · Destroyed > The helicopter experienced a main rotor drive system disconnect, an uncontrolled descent & subsequent inflight collision with terrain in a hilly desert area. This was the third & last in a planned series of marketing demo flts conducted for three USMC… ## The whole list in SQL Runs in DuckDB 1.2 or later on the release's Parquet files over HTTPS: ```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 ('03020') 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 ``` This list as a web page: https://openairdocs.org/ntsb?engine=03020&occurrence=130 --- OpenAirDocs.org is an independent research project of [Contrail Labs](https://contraillabs.com/). It is not affiliated with the FAA or the NTSB. Source documents are U.S. government works in the public domain.