# Final NTSB investigations: Lycoming VO-540 series

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.

Page 1 of 8 · 375 cases

## Latest cases

- [NTSB WPR25LA246](https://openairdocs.org/ntsb/WPR25LA246.md): Hiller UH-12E · Fobes Hill, WA · Accident · No injuries · Class 4 · Limited · Final report · Aug 11, 2025 · N703WA · Substantial damage
  > The pilot’s abrupt maneuver to avoid a powerline during an aerial application flight, which resulted in the helicopter’s impact with terrain.
- [NTSB WPR22LA245](https://openairdocs.org/ntsb/WPR22LA245.md): Hiller UH-12E · Wenatchee, WA · Accident · Serious injuries · Class 4 · Limited · Final report · Jul 6, 2022 · N130HA · Destroyed
  > The pilot’s failure to maintain clearance from power lines during low-level operations in light rain conditions.
- [NTSB ERA22LA118](https://openairdocs.org/ntsb/ERA22LA118.md): Hiller UH-12E4 · Shrewsbury, PA · Accident · No injuries · Class 4 · Limited · Final report · Feb 9, 2022 · N64741 · Substantial damage
  > The pilot’s failure to maintain control during the descent which resulted in a hard landing.
- [NTSB ERA17LA285](https://openairdocs.org/ntsb/ERA17LA285.md): Bell 47G · St Marys, PA · Accident · No injuries · Limited investigation · Final report · Aug 20, 2017 · N9526 · Substantial damage
  > The student pilot's inadequate prefight planning and en route fuel management, which resulted in fuel exhaustion and a total loss of engine power.
- [NTSB GAA15CA202](https://openairdocs.org/ntsb/GAA15CA202.md): Bell 47G · De Queen, AR · Accident · Minor injuries · Data collection · Final report · Jul 25, 2015 · N1420W · Substantial damage
  > The pilot's failure to conduct helicopter performance planning, which resulted in an uncontrolled descent and impact with a truck and terrain during takeoff from an elevated platform.
- [NTSB CEN15LA322](https://openairdocs.org/ntsb/CEN15LA322.md): Bell 47G 4A · Gilbert, IA · Accident · No injuries · Limited investigation · Final report · Jul 24, 2015 · N1396X · Substantial damage
  > The total loss of engine power due to fuel starvation because the available fuel shifted within the tanks due to an abrupt nose-low maneuver to avoid an obstacle, which resulted in a hard forced landing.
- [NTSB WPR15LA138](https://openairdocs.org/ntsb/WPR15LA138.md): Hiller UH 12E · Firebaugh, CA · Accident · No injuries · Limited investigation · Final report · Mar 29, 2015 · N130HA · Substantial damage
  > A loss of engine power for reasons that could not be determined because postaccident examination of the engine did not reveal any anomalies that would have precluded normal operation.
- [NTSB ERA14LA405](https://openairdocs.org/ntsb/ERA14LA405.md): Hiller UH 12E · Cape May Court House, NJ · Accident · Minor injuries · Limited investigation · Final report · Aug 25, 2014 · N4035A · Substantial damage
  > The mechanic’s failure to detect excessive wear on the engine’s lateral snubber vibration mount during the latest annual inspection, which resulted in an in-flight engine failure and a subsequent forced landing.
- [NTSB WPR14LA062](https://openairdocs.org/ntsb/WPR14LA062.md): Hiller UH 12E · Chowchilla, CA · Accident · No injuries · Limited investigation · Final report · Dec 9, 2013 · N36MV · Substantial damage
  > The failure of the torsional drive coupling, which resulted in a loss of drive to the main rotor system during low-altitude flight.
- [NTSB WPR12LA115](https://openairdocs.org/ntsb/WPR12LA115.md): Texas Helicopter OH-13E/M74 · Farmington, CA · Accident · Serious injuries · Limited investigation · Final report · Feb 22, 2012 · N43921 · Substantial damage
  > The in-flight separation of the wood portion of one main rotor blade while maneuvering at low level, the reason for which could not be determined because postaccident examination did not reveal any anomalies that would have precluded normal operation.
- [NTSB CEN11CA403](https://openairdocs.org/ntsb/CEN11CA403.md): Bell 47G-4A · Montgomery City, MO · Accident · No injuries · Data collection · Final report · Jun 18, 2011 · N24HM · Substantial damage
  > A loss of control during the precautionary landing, which resulted in inadvertent contact between the main rotor and the tailboom. Contributing to the accident was the overloaded condition.
- [NTSB ERA11LA216](https://openairdocs.org/ntsb/ERA11LA216.md): Hiller UH-12E · Culpeper, VA · Accident · No injuries · Limited investigation · Final report · Mar 25, 2011 · N4033P · Substantial damage
  > Mechanical failure of the transmission for reasons that could not be determined because the transmission could not be torn down.
- [NTSB WPR11CA146](https://openairdocs.org/ntsb/WPR11CA146.md): Hiller UH-12E · Colusa, CA · Accident · No injuries · Data collection · Final report · Feb 26, 2011 · N236HA · Substantial damage
  > The pilot's failure to maintain an adequate airspeed and an inadvertent encounter with settling with power while flying downwind.
- [NTSB CEN11LA117](https://openairdocs.org/ntsb/CEN11LA117.md): Piper PA-46-350P · Lake Elmo, MN · Accident · Minor injuries · Limited investigation · Final report · Dec 18, 2010 · N92358 · Substantial damage
  > The pilot's improper fuel management which resulted in the loss of engine power due to fuel starvation. Contributing to the accident was the distraction of the cabin depressurization.
- [NTSB CEN10CA362](https://openairdocs.org/ntsb/CEN10CA362.md): Hiller UH-12E · Grand Junction, CO · Accident · Minor injuries · Data collection · Final report · Jun 25, 2010 · N9754C · Substantial damage
  > The total loss of engine power for undetermined reasons.
- [NTSB WPR10CA283](https://openairdocs.org/ntsb/WPR10CA283.md): Bell 47G-4A · Shaw Island, WA · Accident · No injuries · Data collection · Final report · Jun 8, 2010 · N7069J · Substantial damage
  > The passenger's inadvertent movement of the mixture control during climb, resulting in a loss of engine power.
- [NTSB WPR10LA127](https://openairdocs.org/ntsb/WPR10LA127.md): Hiller UH-12E · Los Banos, CA · Accident · No injuries · Limited investigation · Final report · Feb 2, 2010 · N36MV · Substantial damage
  > A partial loss of engine power due to a failure of the throttle interconnect hardware, which resulted in a hard landing.
- [NTSB WPR10LA117](https://openairdocs.org/ntsb/WPR10LA117.md): Bell 47G-4A · Shafter, CA · Accident · Minor injuries · Limited investigation · Final report · Jan 22, 2010 · N28938 · Substantial damage
  > The loss of a main rotor blade counterweight due to corrosion. Contributing to the accident was the failure of the operator to perform the initial and recurrent inspections required by a Service Bulletin to detect the corrosion in the counterweight.
- [NTSB WPR10CA094](https://openairdocs.org/ntsb/WPR10CA094.md): Hiller UH-12E · Tipton, CA · Accident · Minor injuries · Data collection · Final report · Jan 1, 2010 · N440NR · Substantial damage
  > The pilot's failure to maintain clearance from terrain.
- [NTSB CEN09CA517](https://openairdocs.org/ntsb/CEN09CA517.md): Bell 47G-2A · Covert, MI · Accident · No injuries · Data collection · Final report · Aug 11, 2009 · N9526 · Substantial damage
  > A loss of engine power due to fuel starvation as a result of blocked fuel vents.
- [NTSB CEN09CA359](https://openairdocs.org/ntsb/CEN09CA359.md): Hiller UH-12E · Stringtown, OK · Accident · No injuries · Data collection · Final report · Jun 11, 2009 · N34SD · Substantial damage
  > The pilot's failure to maintain clearance from power lines. Contributing to the accident was the pilot's preoccupation with personal affairs.
- [NTSB WPR09LA028](https://openairdocs.org/ntsb/WPR09LA028.md): Hiller UH-12E · Powder River, WY · Accident · Minor injuries · Limited investigation · Final report · Oct 30, 2008 · N61436 · Substantial damage
  > A flight control system malfunction while the helicopter was maneuvering at low altitude due to the failure/separation of the rotor blade control tube.
- [NTSB WPR09CA008](https://openairdocs.org/ntsb/WPR09CA008.md): Bell 47J-2A · Florence, AZ · Accident · No injuries · Data collection · Final report · Oct 11, 2008 · N8567F · Substantial damage
  > The pilot’s inadequate compensation for a wind shift encountered during the landing approach, which resulted in a hard landing and rollover. Contributing to the accident was the encounter with the wind shift.
- [NTSB CHI08CA252](https://openairdocs.org/ntsb/CHI08CA252.md): Hiller UH-12E · Cokato, MN · Accident · No injuries · Data collection · Final report · Aug 15, 2008 · N945HA · Substantial damage
  > The pilot did not visually identify and maintain clearance with the power lines, and the pilot's inability to maintain control of the helicopter once it contacted the power lines. Factors associated with the accident were the low altitude operations being…
- [NTSB CHI08LA211](https://openairdocs.org/ntsb/CHI08LA211.md): Bell 47G-4A · Mayville, WI · Accident · 1 fatal · Limited investigation · Final report · Jul 24, 2008 · N24HM · Minor damage
  > The pilot's failure to maintain clearance with the rotating rotor blades after he exited the helicopter after landing.
- [NTSB DFW08LA100](https://openairdocs.org/ntsb/DFW08LA100.md): Hiller UH-12E · Quinton, OK · Accident · No injuries · Limited investigation · Final report · Apr 7, 2008 · N34SD · Substantial damage
  > An undetermined mechanical malfuction associated with the tail rotor drive system which led to a loss of control.
- [NTSB DEN08LA071](https://openairdocs.org/ntsb/DEN08LA071.md): Hiller UH-12E · La Porte, TX · Accident · Minor injuries · Limited investigation · Final report · Apr 4, 2008 · N40289 · Substantial damage
  > The loss of tail rotor effectiveness. Contributing factors were the sudden windshift to a tailwind, and the pilot initiating a hovering turn in ground effect.
- [NTSB DFW06CA013](https://openairdocs.org/ntsb/DFW06CA013.md): Hiller UH-12E · Pasadena, TX · Accident · Serious injuries · Data collection · Final report · Oct 23, 2005 · N909BC · Substantial damage
  > The pilot's inadequate fuel management, which resulted in fuel exhaustion and a loss of engine power. A contributing factor was the lack of suitable terrain for the forced landing.
- [NTSB LAX05CA313](https://openairdocs.org/ntsb/LAX05CA313.md): Hiller UH 12-E · Five Points, CA · Accident · No injuries · Data collection · Final report · Sep 22, 2005 · N141HA · Substantial damage
  > The pilot's failure to refuel the helicopter, which resulted in fuel exhaustion.
- [NTSB LAX05LA187](https://openairdocs.org/ntsb/LAX05LA187.md): Bell 47G-4A · Bakersfield, CA · Accident · Serious injuries · Limited investigation · Final report · May 25, 2005 · N110DT · Destroyed
  > the pilot's inadequate visual lookout and failure to maintain clearance from the power lines.
- [NTSB SEA05CA104](https://openairdocs.org/ntsb/SEA05CA104.md): Hiller UH-12E · Estacada, OR · Accident · Minor injuries · Data collection · Final report · May 23, 2005 · N3030H · Substantial damage
  > The failure of the pilot to maintain landing skid clearance during hover taxi, which resulted in a dynamic rollover. A factor was the gusty wind condition.
- [NTSB FTW04LA198](https://openairdocs.org/ntsb/FTW04LA198.md): Bell 47-G2 · La Porte, TX · Accident · Serious injuries · Limited investigation · Final report · Aug 1, 2004 · N7892B · Destroyed
  > The loss of engine power for undetermined reasons.
- [NTSB SEA04LA073](https://openairdocs.org/ntsb/SEA04LA073.md): Hiller UH-12E · Haines, OR · Accident · Minor injuries · Limited investigation · Final report · Apr 26, 2004 · N9785C · Substantial damage
  > A momentary partial loss of power for undetermined reason(s) and the pilot's failure to maintain adequate RPM during his autorotation landing.
- [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 LAX03CA284](https://openairdocs.org/ntsb/LAX03CA284.md): Hiller UH12E · Kekaha, HI · Accident · No injuries · Data collection · Final report · Sep 9, 2003 · N9792C · Substantial damage
  > the pilot's failure to maintain clearance with the wires due to an inadequate visual lookout.
- [NTSB CHI03LA185](https://openairdocs.org/ntsb/CHI03LA185.md): Hiller UH-12E · Elk Mound, WI · Accident · Minor injuries · Limited investigation · Final report · Jun 27, 2003 · N62417 · Destroyed
  > The pilot's failure to maintain clearance from the terrain. Factors contributing to the accident were the whirlwind, the turbulence, and the helicopter's low altitude.
- [NTSB LAX03LA197](https://openairdocs.org/ntsb/LAX03LA197.md): Bell 47-G4 · Porterville, CA · Accident · 1 fatal · Limited investigation · Final report · Jun 13, 2003 · N9017N · Destroyed
  > loss of control for undetermined reasons.
- [NTSB FTW03CA146](https://openairdocs.org/ntsb/FTW03CA146.md): Bell 47G-4 · Robinson, TX · Accident · Minor injuries · Data collection · Final report · May 12, 2003 · N4205D · Substantial damage
  > The pilot's failure to maintain clearance with the ground while performing a quick stop maneuver which resulted in a dynamic rollover.
- [NTSB FTW02LA186](https://openairdocs.org/ntsb/FTW02LA186.md): Bell 47G4 · Grand Lake, LA · Accident · Minor injuries · Limited investigation · Final report · Jun 23, 2002 · N62446 · Destroyed
  > the pilot's inability to control the helicopter in a hover due to the restricted movement of the cyclic for undetermined reasons.
- [NTSB ATL02FA107](https://openairdocs.org/ntsb/ATL02FA107.md): Bell 47G-4A · Yauco, PR · Accident · 1 fatal · Field investigation · Final report · May 25, 2002 · N6SR · Destroyed
  > The pilot's failure to apply carburetor heat that resulted in a partial loss of engine power and the subsequent collision with an object during the forced landing. A factor was weather conditions favorable for the formation of carburetor ice.
- [NTSB CHI02LA142](https://openairdocs.org/ntsb/CHI02LA142.md): Bell 47G-4 · Muncie, IN · Accident · No injuries · Limited investigation · Final report · May 24, 2002 · N1915B · Destroyed
  > The pilot did not maintain directional control during hover taxi. Inadequate compensation for the crosswind conditions, the light rain, and the light pole were factors in the accident.
- [NTSB NYC02LA090](https://openairdocs.org/ntsb/NYC02LA090.md): Bell 47J-2A · Blairstown, NJ · Accident · No injuries · Limited investigation · Final report · May 1, 2002 · N37731 · Substantial damage
  > The pilot's improper flare, and his failure to maintain obstacle clearance which resulted in a tail strike.
- [NTSB SEA02LA073](https://openairdocs.org/ntsb/SEA02LA073.md): Hiller UH-12E · Goshen, OR · Accident · No injuries · Limited investigation · Final report · Apr 22, 2002 · N3004T · Substantial damage
  > The failure of company maintenance personnel to identify and replace/repair the degraded exhaust stack. Contributing factors were the mis-rigged carburetor heat control and the pilot's failure to maintain appropriate rotor RPM. Additional contributing factors…
- [NTSB ATL02LA044](https://openairdocs.org/ntsb/ATL02LA044.md): Hiller UH12E · Miami, FL · Accident · Minor injuries · Limited investigation · Final report · Feb 11, 2002 · N103HA · Substantial damage
  > Fatigue cracking in the main rotor hub that resulted in the separation of the main rotor system. A factor was corrosive deposits on the exposed portion of the plate set pin.
- [NTSB LAX01LA276](https://openairdocs.org/ntsb/LAX01LA276.md): Bell 47G-4A · Strathmore, CA · Accident · Minor injuries · Limited investigation · Final report · Aug 11, 2001 · N4262Y · Destroyed
  > The pilot's inadequate visual lookout while maneuvering during an aerial application flight.
- [NTSB CHI01LA238](https://openairdocs.org/ntsb/CHI01LA238.md): Hiller UH-12E · Hastings, NE · Accident · No injuries · Limited investigation · Final report · Jul 25, 2001 · N67067 · Substantial damage
  > Aircraft control not being maintained by the pilot which resulted in the encountered settling with power flight condition during the initial climb. Factors to the accident were the reported variable winds during the takeoff and the corn crop.
- [NTSB LAX01LA245](https://openairdocs.org/ntsb/LAX01LA245.md): Hiller UH-12E · Blythe, CA · Accident · No injuries · Limited investigation · Final report · Jul 13, 2001 · N9281P · Substantial damage
  > The selection by the pilot of an unsuitable precautionary landing site on soft, uneven terrain, which resulted in a rollover.
- [NTSB LAX01LA196](https://openairdocs.org/ntsb/LAX01LA196.md): Bell 47G-4A · Buttonwillow, CA · Accident · No injuries · Limited investigation · Final report · May 31, 2001 · N110DT · Substantial damage
  > The pilot's inadequate in-flight planning that resulted in settling with power during an aerial application turn-to-reverse direction and collision with the ground. Factors were high density altitude and a wind shift.
- [NTSB LAX00LA116](https://openairdocs.org/ntsb/LAX00LA116.md): Bell 47G-4A · Wasco, CA · Accident · No injuries · Limited investigation · Final report · Mar 7, 2000 · N1354X · Substantial damage
  > The pilot's failure to use carburetor heat, which resulted in a loss of engine power. Factors included the ambient carburetor icing conditions and the lack of suitable terrain for the forced landing.
- [NTSB LAX00LA107](https://openairdocs.org/ntsb/LAX00LA107.md): Hiller H-12E · Byron, CA · Accident · Minor injuries · Limited investigation · Final report · Feb 21, 2000 · N61PC · Substantial damage
  > The pilot's inadequate visual lookout while maneuvering in proximity to wires. A contributing factor was the sun glare, which reduced the wire's conspicuity.

Next page: https://openairdocs.org/ntsb.md?engine=41534&status=final&page=2

## 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."completionStatus" = 'Completed'
  AND 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'))
ORDER BY c."eventDate" DESC, c."ntsbNumber" DESC
```

This list as a web page: https://openairdocs.org/ntsb?engine=41534&status=final

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