# NTSB investigations: Lycoming VO-435 series, WA

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 WPR14CA290](https://openairdocs.org/ntsb/WPR14CA290.md): Bell 47K · Kingston, WA · Accident · Minor injuries · Data collection · Final report · Jul 11, 2014 · N88771 · Substantial damage
  > The pilot's failure to maintain aircraft control during the landing approach, which resulted in an excessive descent angle and settling with power.
- [NTSB SEA05LA138](https://openairdocs.org/ntsb/SEA05LA138.md): Bell 47G-2A · Oroville, WA · Accident · No injuries · Limited investigation · Final report · Jul 5, 2005 · N38926 · Substantial damage
  > The failure of the throttle cable housing, which permitted the engine's RPM to decay to the idle position. Contributing factors were the trees and the lack of suitable terrain for a forced landing.
- [NTSB SEA99LA149](https://openairdocs.org/ntsb/SEA99LA149.md): Bell 47G-2 · Benton City, WA · Accident · 1 fatal · Limited investigation · Final report · Aug 26, 1999 · N11VH · Destroyed
  > A loss of power for undetermined reasons and the failure of the pilot to maintain adequate rotor RPM following the power loss. Contributing factors were the pilot's lack of certification and total experience.
- [NTSB SEA95LA227](https://openairdocs.org/ntsb/SEA95LA227.md): Texas Helicopter OH-13E · Yakima, WA · Accident · No injuries · Limited investigation · Final report · Sep 20, 1995 · N38115 · Substantial damage
  > Fatigue failure of the bolt attaching the scissor arm assembly to the pitch control support assembly. The failure of the bolt led to a loss of collective pitch control and reduced rotor RPM.
- [NTSB SEA91LA077](https://openairdocs.org/ntsb/SEA91LA077.md): Bell BH-47G2A · Waitsburg, WA · Accident · No injuries · Limited investigation · Final report · Mar 31, 1991 · N38926 · Substantial damage
  > The improper installation of the main rotor mast nut and lock washer by maintenance personnel which resulted in the separation of the main rotor system.
- [NTSB SEA89LA098](https://openairdocs.org/ntsb/SEA89LA098.md): Bell 47G-2 · Buena, WA · Accident · Serious injuries · Limited investigation · Final report · Jun 2, 1989 · N41721 · Destroyed
  > The pilot's failure to maintain an adequate visual lookout and clearance to avoid the power lines.
- [NTSB SEA86LA177](https://openairdocs.org/ntsb/SEA86LA177.md): Bell 47G3B2 · Nahcotta, WA · Accident · Minor injuries · Limited investigation · Final report · Jul 21, 1986 · N7092J · Destroyed
  > While spraying oyster beds the pilot inadvertently flew the helicopter into the ground.
- [NTSB SEA86LA168](https://openairdocs.org/ntsb/SEA86LA168.md): Bell 47G2A · Chehalis, WA · Accident · No injuries · Limited investigation · Final report · Jul 13, 1986 · N12848 · Substantial damage
  > During an aerial applications maneuver, a complete loss of power occurred. The power loss was caused by failure of the connecting rod bolt. The acft was too low for autorotation and the aircraft struck the ground tail low. The main rotor blade then struck the…
- [NTSB SEA86LA143](https://openairdocs.org/ntsb/SEA86LA143.md): Bell 47G-2 · Zillah, WA · Accident · No injuries · Limited investigation · Final report · Jun 12, 1986 · N11VH · Destroyed
  > En route to the local spray area a total loss of power occurred along with a loss of oil pressure. The acft was aprx 200 ft AGL over a pear orchard. The plt was attempting to autorotate onto a nearby road but the left skid caught the roof top of a metal shed.…
- [NTSB SEA86LA089](https://openairdocs.org/ntsb/SEA86LA089.md): Hiller 12E · Walla Walla, WA · Accident · No injuries · Limited investigation · Final report · Mar 30, 1986 · N87595 · Destroyed
  > A catastrophic failure of the planetary gear of the transmission occurred about 51 flight hours after overhaul. During forced landing a hard landing occurred severing the tail boom. A fire then erupted.
- [NTSB SEA85LA155](https://openairdocs.org/ntsb/SEA85LA155.md): Bell 47G2 · Roosevelt, WA · Accident · No injuries · Limited investigation · Final report · Jul 2, 1985 · N11VH · Substantial damage
  > A total loss of power occurred while on a CFR 137 flight, due to fuel exhaustion. Although the fuel gauge showed 1/2 tank of fuel, the pilot failed to visually check the fuel prior to this flight. During autorotation onto a wheat field a hard landing occurred…
- [NTSB SEA84LA132](https://openairdocs.org/ntsb/SEA84LA132.md): Bell 47G2A · Buena, WA · Accident · No injuries · Limited investigation · Final report · Jun 14, 1984 · N11VH · Substantial damage
  > Main rotor blades contacted a wind machine during an aerial application flt. Helicopter settled into trees and rolled over. Plt said he knew the machine was there but had forgotten.
- [NTSB SEA83LA122](https://openairdocs.org/ntsb/SEA83LA122.md): Bell 47G-2 · Zillah, WA · Accident · No injuries · Limited investigation · Final report · Jun 11, 1983 · N41721 · Substantial damage
  > The rotorcraft made a hard landing after colliding with trees during an autorotation. The acft had experienced an enginefailure while on a repositioning flight between aerial application operations and was forced to land. The acft was autorotated into an…
- [NTSB SEA82DA112](https://openairdocs.org/ntsb/SEA82DA112.md): Bell 47G-2 · Harrah, WA · Accident · Serious injuries · Final report · Jul 15, 1982 · N6145C · Substantial damage
  > The pilot reported that before taking off, the fuel quantity guages indicated there was sufficient fuel to complete one more load and still have an adequate reserve. After dispensing the load, the engine lost power while he was returning to the nurse truck.…
- [NTSB SEA82DA072](https://openairdocs.org/ntsb/SEA82DA072.md): Bell 47G-2 · Grandview, WA · Accident · No injuries · Final report · May 18, 1982 · N11VH · Substantial damage
  > While dispensing herbicide (systox) over an apple orchard the pilot sensed that the engine was binding followed by a power loss. The pilot elected to dump the herbicide and performed a power-off autorotation landing in a grape vineyard. Investigation revealed…
- [NTSB SEA82DA050](https://openairdocs.org/ntsb/SEA82DA050.md): Bell 47G-2A · Lyle, WA · Accident · No injuries · Final report · Apr 10, 1982 · N11VH · Substantial damage
  > During takeoff with a load of fertilizer, insufficient power was available to maintain engine and rotor RPM and sustain flight. The pilot dumped the load, but was unable to avoid ground contact. The tail rotor struck first and separated from the aircraft. The…
- [NTSB SEA81DYE31](https://openairdocs.org/ntsb/SEA81DYE31.md): Hiller UN-12D · Castle Rock, WA · Accident · Minor injuries · Closed · Jun 10, 1981 · N62377 · Destroyed
- [NTSB SEA80DYE03](https://openairdocs.org/ntsb/SEA80DYE03.md): Hiller Acft UH-12D · Amanda Park, WA · Accident · No injuries · Closed · Oct 29, 1979 · N62377 · Substantial damage
- [NTSB SEA79DYP20](https://openairdocs.org/ntsb/SEA79DYP20.md): EL Tomcat MK5A · Moses Lake, WA · Accident · No injuries · Closed · May 15, 1979 · N9044T · Destroyed
- [NTSB SEA79AA029](https://openairdocs.org/ntsb/SEA79AA029.md): Hiller UH12D · Chehalis, WA · Accident · 1 fatal · Closed · Apr 3, 1979 · N64867 · Minor damage
- [NTSB SEA78FA052](https://openairdocs.org/ntsb/SEA78FA052.md): Bell 47G3B1 · Snoqualmie Fls, WA · Accident · No injuries · Closed · Aug 7, 1978 · N1182W · Destroyed
- [NTSB SEA78DYP33](https://openairdocs.org/ntsb/SEA78DYP33.md): Bell 47G-2 · Benton City, WA · Accident · No injuries · Closed · Jun 7, 1978 · N31552 · Destroyed
- [NTSB SEA78DYM23](https://openairdocs.org/ntsb/SEA78DYM23.md): Bell 47G-2 · Goldendale, WA · Accident · No injuries · Closed · Apr 7, 1978 · N41721 · Substantial damage
- [NTSB SEA76DYC66](https://openairdocs.org/ntsb/SEA76DYC66.md): Bell 47G3B2 · Vancouver, WA · Accident · No injuries · Closed · Aug 11, 1976 · N7092J · Destroyed
- [NTSB SEA76FYG53](https://openairdocs.org/ntsb/SEA76FYG53.md): Bell 47G-2 · Eltopia, WA · Accident · Minor injuries · Closed · Jun 9, 1976 · N2483B · Destroyed
- [NTSB SEA75AS022](https://openairdocs.org/ntsb/SEA75AS022.md): Bell 47G-2 · Kingston, WA · Accident · 1 fatal · Closed · Nov 4, 1974 · N5160B · Destroyed
- [NTSB SEA75FYG10](https://openairdocs.org/ntsb/SEA75FYG10.md): Bell 47G-2 · Quincy, WA · Accident · Serious injuries · Closed · Aug 27, 1974 · N6717D · Destroyed
- [NTSB SEA75DYG07](https://openairdocs.org/ntsb/SEA75DYG07.md): Bell 47G-2 · Royal City, WA · Accident · No injuries · Closed · Aug 14, 1974 · N6717D · Substantial damage
- [NTSB SEA75FYE11](https://openairdocs.org/ntsb/SEA75FYE11.md): Bell 47G-2A · Mercer Isl, WA · Accident · Serious injuries · Closed · Aug 11, 1974 · N88AR · Destroyed
- [NTSB SEA74DYG49](https://openairdocs.org/ntsb/SEA74DYG49.md): Bell 47G-2 · Ephrata, WA · Accident · No injuries · Closed · Jun 24, 1974 · N2899B · Substantial damage
- [NTSB SEA74DYG38](https://openairdocs.org/ntsb/SEA74DYG38.md): Bell 47G-2 · Ephrata, WA · Accident · Minor injuries · Closed · May 4, 1974 · N7887B · Substantial damage
- [NTSB SEA74DYE39](https://openairdocs.org/ntsb/SEA74DYE39.md): Bell 47G-2 · Forks, WA · Accident · No injuries · Closed · Mar 3, 1974 · N5161B · Substantial damage
- [NTSB SEA74DYC25](https://openairdocs.org/ntsb/SEA74DYC25-186907.md): Bell 47G-2 · Spokane, WA · Accident · No injuries · Closed · Feb 24, 1974 · N59H · Substantial damage
- [NTSB SEA74DYE20](https://openairdocs.org/ntsb/SEA74DYE20.md): Bell 47F-2 · Forks, WA · Accident · No injuries · Closed · Oct 8, 1973 · N5161B · Substantial damage
- [NTSB SEA73DYG02](https://openairdocs.org/ntsb/SEA73DYG02.md): Bell 47G-2 · Twisp, WA · Accident · No injuries · Closed · Jul 7, 1972 · N6717D · Substantial damage
- [NTSB SEA72DYG45](https://openairdocs.org/ntsb/SEA72DYG45.md): Bell 47G-2 · Warden, WA · Accident · No injuries · Closed · Jun 4, 1972 · N1657 · Substantial damage
- [NTSB SEA72DYE16](https://openairdocs.org/ntsb/SEA72DYE16.md): Bell 47G2 · Clallam Bay, WA · Accident · No injuries · Closed · Oct 6, 1971 · N5160B · Substantial damage
- [NTSB SEA71FWG17](https://openairdocs.org/ntsb/SEA71FWG17.md): Bell 47G-2 · Wenatchee, WA · Accident · Minor injuries · Closed · Sep 9, 1970 · N2483B · Substantial damage
- [NTSB SEA71DWD09](https://openairdocs.org/ntsb/SEA71DWD09.md): Bell 47G3B1 · Diablo, WA · Accident · Minor injuries · Closed · Aug 7, 1970 · N1182W · Substantial damage
- [NTSB SEA70FWD13](https://openairdocs.org/ntsb/SEA70FWD13.md): Bell 47-G2 · Maple Valley, WA · Accident · No injuries · Closed · May 9, 1970 · N6141 · Substantial damage
- [NTSB SEA70DWD05](https://openairdocs.org/ntsb/SEA70DWD05.md): Bell 47G-2 · Rochester, WA · Accident · No injuries · Closed · Feb 25, 1970 · N2899B · Substantial damage
- [NTSB SEA70D0034](https://openairdocs.org/ntsb/SEA70D0034.md): Bell 47G-2 · Centralia, WA · Accident · Serious injuries · Closed · May 18, 1969 · N2498B · Destroyed
- [NTSB SEA68D0297](https://openairdocs.org/ntsb/SEA68D0297.md): Bell 47G-2 · Mansfield, WA · Accident · No injuries · Closed · May 10, 1968 · N6717D · Substantial damage
- [NTSB SEA68D0296](https://openairdocs.org/ntsb/SEA68D0296.md): Bell 47G-2 · Bridgeport, WA · Accident · No injuries · Closed · Apr 24, 1968 · N6717D · Substantial damage
- [NTSB SEA67A0071](https://openairdocs.org/ntsb/SEA67A0071.md): Bell 47G-2 · Kennewick, WA · Accident · No injuries · Closed · Jun 1, 1967 · N6145C · Substantial damage
- [NTSB SEA66A0032](https://openairdocs.org/ntsb/SEA66A0032.md): Bell 47G-2 · 38mi E.Kelso, WA · Accident · Minor injuries · Closed · Nov 23, 1965 · N6145C · Substantial damage
- [NTSB SEA65A0047](https://openairdocs.org/ntsb/SEA65A0047.md): Bell 47G-2 · Wenatchee, WA · Accident · Minor injuries · Closed · Mar 13, 1965 · N2483B · Destroyed
- [NTSB UNK64X3325](https://openairdocs.org/ntsb/UNK64X3325.md): Bell B-47G2 · Monitor, WA · Incident · No injuries · Closed · Aug 11, 1964 · N2483B · No damage
- [NTSB UNK64X2719](https://openairdocs.org/ntsb/UNK64X2719.md): Bell 47G3 · Manson, WA · Accident · 1 fatal · Closed · Jul 8, 1964 · N8441E · Destroyed

## 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."eventStateOrRegion" = 'WA' AND c."eventCountry" = 'USA'
  AND c."mKey" IN (SELECT x.case_mkey FROM 'https://openairdocs.org/data/latest/ntsb_aircrafts.parquet' x WHERE x.engine_model_code IN ('41525'))
ORDER BY c."eventDate" DESC, c."ntsbNumber" DESC
```

This list as a web page: https://openairdocs.org/ntsb?engine=41525&state=WA

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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.