# NTSB investigations: Lycoming T-53 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 SEA01LA046](https://openairdocs.org/ntsb/SEA01LA046.md): Western International UH-1H · Darby, MT · Accident · 1 fatal · Limited investigation · Final report · Feb 7, 2001 · N205GL · Substantial damage > Inflight loss of a tail rotor pitch change link-to-blade grip attach bolt, resulting partial loss of tail rotor control, and subsequent entanglement of the helicopter's external load cable with a tree during emergency descent. Factors included the pilot's… - [NTSB MIA00LA170](https://openairdocs.org/ntsb/MIA00LA170.md): Southwest Florida SW204 · Fort Pierce, FL · Accident · No injuries · Limited investigation · Final report · May 24, 2000 · N37BA · Substantial damage > An in-flight separation of a tail rotor blade tip weight resulting in tail rotor assembly imbalance and separation due to the installation of an unapproved rotor blade by company maintenance personnel, and the subsequent collision with trees during an… - [NTSB LAX99LA283](https://openairdocs.org/ntsb/LAX99LA283.md): Bell UH-1B · Lost Hills, CA · Accident · No injuries · Limited investigation · Final report · Aug 25, 1999 · N999SJ · Substantial damage > Failure and separation of the 90-degree gearbox as a result of the disengagement of the pinion and gear teeth. The cause(s) of the pinion and gear disengagement were undetermined. - [NTSB SEA99LA020](https://openairdocs.org/ntsb/SEA99LA020.md): Garlick UH-1H · Darrington, WA · Accident · Serious injuries · Limited investigation · Final report · Dec 14, 1998 · N94NW · Substantial damage > The total separation of the vertical fin (stabilizer), as the result of fatigue cracks which initiated in the fourth rivet hole above where the fin extends from the tailboom. - [NTSB SEA98LA017](https://openairdocs.org/ntsb/SEA98LA017.md): Bell TH-1L · Canby, OR · Accident · Minor injuries · Limited investigation · Final report · Nov 25, 1997 · N8160G · Substantial damage > The pilot's allowance of excessive airspeed resulting in the long-line hook impacting the tail rotor, and his allowance of an airspeed bleed-off preventing a successful run-on landing due to a loss of yaw control. - [NTSB SEA97FA196](https://openairdocs.org/ntsb/SEA97FA196.md): Southern Aero UH-1B · Skykomish, WA · Accident · 1 fatal · Field investigation · Final report · Aug 27, 1997 · N896W · Substantial damage > A fatigue fracture in the main rotor mast, which resulted in an in flight separation of the main rotor from the helicopter. Contributing to the accident was insufficient Federal Aviation Administration airworthiness standards and requirements for the aircraft. - [NTSB MIA97TA139](https://openairdocs.org/ntsb/MIA97TA139.md): Bell 204-B · Calderwood, TN · Accident · No injuries · Final report · Apr 16, 1997 · N4580Y · Destroyed > The inadequate maintenance inspection of the helicopter resulting in loss of lubrication from the main drive shaft going undetected until failure of the drive shaft. - [NTSB SEA96FA187](https://openairdocs.org/ntsb/SEA96FA187.md): Garlick UH-1H · Coeur D'Alene, ID · Accident · Serious injuries · Field investigation · Final report · Aug 12, 1996 · N97NW · Substantial damage > Fatigue fracture of the left forward vertical stabilizer spar, resulting in loss of the vertical stabilizer and tail rotor and subsequent loss of control. A factor was insufficient applicability (by make and model) of an existing FAA airworthiness directive… - [NTSB BFO94LA159](https://openairdocs.org/ntsb/BFO94LA159.md): Bell UH-1B · Carrabasset, ME · Accident · No injuries · Limited investigation · Final report · Aug 31, 1994 · N204JB · Substantial damage > Fracture failure of the tail rotor drive intermediate gearbox. - [NTSB SEA93LA207](https://openairdocs.org/ntsb/SEA93LA207.md): Bell UH-1B · Pierce, ID · Accident · No injuries · Limited investigation · Final report · Sep 23, 1993 · N3979C · Substantial damage > Separation of the 90 degree gearbox after fatigue failure of the gearbox attach bolts. Factors include hilly/mountainous terrain. - [NTSB ANC93FA056](https://openairdocs.org/ntsb/ANC93FA056.md): Bell 204B · Copper Harbor, AK · Accident · 1 fatal · Field investigation · Final report · May 2, 1993 · N204AQ · Destroyed > Fatigue failure of the tail rotor gearbox, and improper helicopter operations being conducted by the operator resulting in repetitive at and over maximum loads. Factors in the accident were: material defect of the tail rotor gear box (inadequate quality… - [NTSB ATL90FA100](https://openairdocs.org/ntsb/ATL90FA100.md): Bell 205A-1 · Moncks Corner, SC · Accident · 1 fatal · Field investigation · Final report · Apr 20, 1990 · N67HJ · Destroyed > The in-flight separation of the main rotor because of the failure of a pillow block bolt, and the failure of the operator/repair station to follow the overhaul procedures. - [NTSB LAX90DUJ05](https://openairdocs.org/ntsb/LAX90DUJ05.md): Bell UH-1E · Mesa, AZ · Accident · No injuries · Final report · Nov 4, 1989 · N138US · Destroyed > The inflight separation of the tail rotor due to improper maintenance procedures and the installation of incorrect attachment hardware on the tail rotor blade pitch change linkages. - [NTSB ATL89FA130](https://openairdocs.org/ntsb/ATL89FA130.md): Bell UH-1E · Aiken, SC · Accident · Serious injuries · Field investigation · Final report · Apr 17, 1989 · N118HS · Substantial damage > Improper installation of a tail rotor pitch change crosshead retention bolt by the company mechanic, which resulted in loosening of the bolt and eventual failure of the tail rotor assembly/blade and subsequent loss of control. Trees at the crash site… - [NTSB LAX86DVA06](https://openairdocs.org/ntsb/LAX86DVA06.md): Bell UH-1B · Chowchilla, CA · Accident · Minor injuries · Final report · Apr 16, 1986 · N910PD · Destroyed > While returning from a spraying operation the plt observed that the main transmission oil pressure gage indicated zero. The plt reported that the engine master caution did not illuminate and that the oil temperature gage was normal. The plt stated that he… - [NTSB MIA84FA166](https://openairdocs.org/ntsb/MIA84FA166.md): Bell UH-1B · Clermont, FL · Accident · 1 fatal · Field investigation · Final report · May 10, 1984 · N2252A · No damage > The plt was not aware that two ground attendants were riding the cable during a logging operation when there was an accidental cable release & the attendants fell to the ground. Examination of the acfts hook did not reveal a system failure or malfunction.… ## 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 ('41552', '41549', '41587') 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=41552&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.