# NTSB investigations: Lycoming VO-540 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 LAX04LA176](https://openairdocs.org/ntsb/LAX04LA176.md): Bell 47G-4A · Bakersfield, CA · Accident · Serious injuries · Limited investigation · Final report · Apr 3, 2004 · N7NB · Substantial damage > a loss of tail rotor drive due to a disconnection of the drive shaft's splined coupling at the tail rotor gear box. The splined coupling to tail rotor gear box disconnection occurred as a result of tail boom flexing due to the combined effects of an… - [NTSB SEA00TA013](https://openairdocs.org/ntsb/SEA00TA013.md): Hiller UH-12E · Stites, ID · Accident · Serious injuries · Final report · Nov 2, 1999 · N5388V · Substantial damage > Inadequate inspection of the control rotor cuff by a company mechanic and subsequent fatigue fracture of the cuff, resulting in an inflight separation of the control rotor blade. Factors contributing to the accident were: inadequate quality control during… - [NTSB SEA99FA013](https://openairdocs.org/ntsb/SEA99FA013.md): Hiller UH-12E · Marshall, WA · Accident · 1 fatal · Field investigation · Final report · Nov 10, 1998 · N752GB · Destroyed > The loss of the bolt that connects the lateral cyclic linkage push rod to the lower end of the upper firewall-mounted lateral cyclic linkage bellcrank, resulting in an uncontrolled descent into the terrain. - [NTSB NYC97LA101](https://openairdocs.org/ntsb/NYC97LA101.md): Hiller UH-12E · Granby, NY · Accident · Serious injuries · Limited investigation · Final report · May 29, 1997 · N4029S · Substantial damage > failure of the pilot/owner to replace the torsional clutch as specified by the manufacturer, and subsequent failure of the helicopter's clutch, which resulted in a forced landing (autorotation). A related factor was: the encounter with trees in the emergency… - [NTSB LAX96LA279](https://openairdocs.org/ntsb/LAX96LA279.md): Hiller UH-12E · Healdsburg, CA · Accident · No injuries · Limited investigation · Final report · Jul 20, 1996 · N124HA · Substantial damage > The failure of the pilot to confirm a loss of power before entering autorotation after reading an erroneous instrument indication on the helicopter's dual tachometer. Factors in the accident were the erratic instrument, and maintenance personnel who failed to… - [NTSB ATL96LA104](https://openairdocs.org/ntsb/ATL96LA104.md): Hiller UH-12E · Cottondale, FL · Accident · No injuries · Limited investigation · Final report · Jul 11, 1996 · N102HT · Substantial damage > failure of the main rotor drive torsional coupling and inner gimbal ring, which resulted in jamming of the flight controls during an attempted autorotation. - [NTSB LAX95LA109](https://openairdocs.org/ntsb/LAX95LA109.md): Hiller UH-12E · Arvin, CA · Accident · No injuries · Limited investigation · Final report · Feb 15, 1995 · N5335V · Substantial damage > The seizure of the transmission due to lack of lubrication from a plugged oil supply line. - [NTSB LAX95LA096](https://openairdocs.org/ntsb/LAX95LA096.md): Hiller UH-12E · Chowchilla, CA · Accident · No injuries · Limited investigation · Final report · Feb 3, 1995 · N9293Z · Destroyed > the in-flight failure and separation of the main rotor hub due to a fatigue crack. - [NTSB LAX94LA043](https://openairdocs.org/ntsb/LAX94LA043.md): Hiller UH-12E · Salinas, CA · Accident · No injuries · Limited investigation · Final report · Nov 13, 1993 · N149HA · Destroyed > The pilot's improper handling of the helicopter which resulted in overloading of the rotor system in a maneuvering turn during aerial application of chemical, and subsequent failure of the main rotor paddle assembly. - [NTSB LAX93LA120](https://openairdocs.org/ntsb/LAX93LA120.md): Bell 47G · Bakersfield, CA · Accident · No injuries · Limited investigation · Final report · Feb 13, 1993 · N1185W · Substantial damage > The clutch slippage and failure of the pilot to jettison the load. - [NTSB LAX92LA349](https://openairdocs.org/ntsb/LAX92LA349.md): Hiller UH12-E, Saloy Conver · Arvin, CA · Accident · Minor injuries · Limited investigation · Final report · Aug 15, 1992 · N9753C · Substantial damage > The failure of the tension torsion bar pin due to fatigue. Contributing to this accident was that it was not possible for the pilot to flare the helicopter on landing. - [NTSB LAX92LA146](https://openairdocs.org/ntsb/LAX92LA146.md): Hiller UH-12E · Huron, CA · Accident · No injuries · Limited investigation · Final report · Mar 21, 1992 · N93478 · Destroyed > A separation of the control rotor cuff due to fatigue. - [NTSB LAX91LA191](https://openairdocs.org/ntsb/LAX91LA191.md): Hiller UH-12E · Delano, CA · Accident · No injuries · Limited investigation · Final report · May 4, 1991 · N4414 · Substantial damage > That the pilot improperly performed the autorotation by misjudging the flare altitude. Contributing to this accident was the total failure of the freewheeling sprag clutch due to excessive wear and the soft dirt terrain. - [NTSB FTW91LA064](https://openairdocs.org/ntsb/FTW91LA064.md): Bell 47G4 · Corpus Christi, TX · Accident · Minor injuries · Limited investigation · Final report · Apr 27, 1991 · N1195W · Destroyed > The initial restricted movement and eventual locking of the cyclic control as a result of the failure of the lateral servo. A factor was the installation of the failed component by an unqualified person. - [NTSB CHI90DTG02](https://openairdocs.org/ntsb/CHI90DTG02.md): Hiller UH-12-E · Garrison, ND · Accident · No injuries · Final report · Aug 4, 1990 · N133HA · Substantial damage > The failure of the helicopter tail rotor control cable. A factor related to the accident was the chafing of the tail rotor control cable. - [NTSB FTW90DPJ05](https://openairdocs.org/ntsb/FTW90DPJ05.md): Bell 47G-4A · Bixby, OK · Accident · Minor injuries · Final report · Apr 14, 1990 · N2238W · Destroyed > Loss of control due to undetermined mechanical failure. - [NTSB ATL90FA089](https://openairdocs.org/ntsb/ATL90FA089.md): Hiller UH-12D · Soddy-Daisy, TN · Accident · 1 fatal · Field investigation · Final report · Mar 31, 1990 · N94496 · Substantial damage > Fatigue induced failure of the collective pitch push rod (adjustable) during flight, and the failure of the pilot to provide routine maintenance. The pilot's lack of expereince and his failure to obtain required training and certification were factors in the… - [NTSB CHI89DEP07](https://openairdocs.org/ntsb/CHI89DEP07.md): Hiller UH-12E · Blackriverfalls, WI · Accident · Minor injuries · Final report · Jul 20, 1989 · N48313 · Destroyed > Pilot-in-command's failure to jettison the external load followed by his misjudgement of distance to avoid collision with the external load. - [NTSB LAX89DVM02](https://openairdocs.org/ntsb/LAX89DVM02.md): Hiller UH-12E · Salinas, CA · Accident · Minor injuries · Final report · Apr 26, 1989 · N169HA · Substantial damage > The separation of the torsion coupling in the main rotor drive system. - [NTSB LAX87DUJ11](https://openairdocs.org/ntsb/LAX87DUJ11.md): Hiller UH-12E · Scottsdale, AZ · Accident · Minor injuries · Final report · Sep 1, 1987 · N236HA · Destroyed > During an aerial application flight, the plt made a turn-around & was starting to make another swath run when he heard a loud 'bang' & then the helicopter collided with terrain. An inspn of the main rotor head & pin revealed the hub had failed from hi cycle… - [NTSB MIA87LA224](https://openairdocs.org/ntsb/MIA87LA224.md): Bell 47J-2A · Orlando, FL · Accident · No injuries · Limited investigation · Final report · Aug 7, 1987 · N8523F · Substantial damage > During the apch to land the tail rotor drive assy failed resulting in a momentary loss of control. The plt then autorotated & landed on the company helipad, during which the helicopter sustained substantial damage. Examination of the tail rotor drive assy… - [NTSB LAX87DVD04](https://openairdocs.org/ntsb/LAX87DVD04.md): Hiller UH-23-D · Brentwood, CA · Accident · No injuries · Final report · Aug 5, 1987 · N61PC · Substantial damage > During an aerial application flight, the tail boom weight separated and contacted the tail rotor. The pilot lost control of the aircraft and collided with a tree and subsequently the terrain. Post acc invest revealed that the 'pip pins' which secure the tail… - [NTSB LAX86DVA13](https://openairdocs.org/ntsb/LAX86DVA13.md): Bell 47G-4A · Shafter, CA · Accident · No injuries · Final report · Aug 8, 1986 · N1185W · Substantial damage > Shortly after departing the loading rig, en route to an agricultural aerial application operation, the forward coupling tail rotor drive shaft failed. The helicopter was about 10 ft above ground level and about 100 ft west of the loading rig. The pilot… - [NTSB LAX86DVA09](https://openairdocs.org/ntsb/LAX86DVA09.md): Hiller UH-12E · Delano, CA · Accident · No injuries · Final report · Jun 17, 1986 · N172ET · Substantial damage > The helicopter rotor blade delaminated shortly after departing the operator's north base at Delano, CA. The investigation determined the blade contained extensive voids on the bond line. The blade was rejected by the manufacturer as being unairworthy. The… - [NTSB LAX86FVM05](https://openairdocs.org/ntsb/LAX86FVM05.md): Hiller UH12E · Castroville, CA · Accident · Minor injuries · Final report · Apr 27, 1986 · N5374V · Destroyed > The acft landed hard and rolled over after the lndg skid failed in a forced lndg. The plt said he was crusing at 500 ft AGL over an open field when he heard a loud bang. The helicopter began to vibrate severely and spiral to the right. The plt lost ground… - [NTSB LAX84LA494](https://openairdocs.org/ntsb/LAX84LA494.md): Hiller UH12ET · Yuma, AZ · Accident · Serious injuries · Limited investigation · Final report · Sep 25, 1984 · N9278Z · Destroyed > The pilot stated that he was carrying a load of pesticide for application on a broccoli field. The aircraft was in level flight, approximately 4 to 8 feet AGL when it became uncontrollable and impacted the ground. The aircraft was consumed by a post crash… - [NTSB SEA84LA174](https://openairdocs.org/ntsb/SEA84LA174.md): Hiller UH-12E · Redmond, OR · Accident · Minor injuries · Limited investigation · Final report · Jul 16, 1984 · N1043L · Substantial damage > The acft collided with the ground after a in-flt main rotor blade separation during an aerial application flt. Inspection of the fracture surface of the failed blade revealed characteristics consistant with the high stress, low cycle fatigue. Lab findings… - [NTSB MKC84LA205](https://openairdocs.org/ntsb/MKC84LA205.md): Hiller H-23D · Neelyville, MO · Accident · No injuries · Limited investigation · Final report · Jul 9, 1984 · N48313 · Destroyed > The acft rolled over during an emergency landing. The plt claimed that the rotor disengaged at about 30 ft AGL during takeoff. After the accident the upper half of the yoke control was found fractured. A lab report stated that no materialdefects were related… - [NTSB LAX84LA294](https://openairdocs.org/ntsb/LAX84LA294.md): Hiller UH-12E (Soloy) · Delano, CA · Accident · Minor injuries · Limited investigation · Final report · May 10, 1984 · N90461 · Substantial damage > The helicopter experienced an inflt failure of an eng mount, pn 63181-5, which bent the collective control rod & forced the the collective pitch into the up position. The helicopter then settled into the grapes it was spraying & made a hard landing. An… - [NTSB ATL83LA355](https://openairdocs.org/ntsb/ATL83LA355.md): Hiller UH-12E · Cameron, SC · Accident · No injuries · Limited investigation · Final report · Sep 5, 1983 · N4029R · Substantial damage > The plt stated that he was on a trimming/swath run at about 15 ft AGL & 15 mph when he heard a strange noise which was followed by a 180 deg yaw. Subsequently, the helicopter crash landed, damaging the tail boom & tail rotor blades and spreading the landing… ## 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 ('41534', '41582') 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=41534&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.