# NTSB LAX84LA294: Hiller UH-12E (Soloy), N90461, Delano, CA, May 10, 1984

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Limited investigation · Final report
- Date: May 10, 1984, 11:00 local (18:00 UTC)
- Place: Delano, CA
- Coordinates: 35.779586, -119.23069 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=35.7796&lon=-119.2307&mi=10
- Phase of flight: [Maneuvering](https://openairdocs.org/ntsb-phases/450) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 24263
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX84LA294
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/24263/pdf
- Page: https://openairdocs.org/ntsb/LAX84LA294

## Sequence of events

In NTSB's coding before 2008 (https://www.ntsb.gov/GILS/Documents/codman.pdf).

- Airframe/component/system failure/malfunction, maneuvering
  - engine assembly,mount - fatigue (cause)
  - engine assembly,mount - failure,total (cause)
  - rotorcraft flight control - disabled
- Hard landing, descent - uncontrolled

## Analysis

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 INVESTIGATION REVEALED THAT THE GUSSET WELD BEADS, JUST BELOW THE OUTER GIMBAL FORWARD ATTACH POINT, HAD FAILED IN FATIGUE.

## Aircraft

- Registration: [N90461](https://openairdocs.org/deregistered/N90461-2013-05-17), registration cancelled 2013-05-17, S/N 2514, built 1965 (OpenAirDocs)
- Reported make and model: HILLER UH-12E (SOLOY) (UH-12E (SO)
- Registry model: [Hiller UH-12L4](https://openairdocs.org/model/hiller-uh-12l4) (registry code 4360128) (OpenAirDocs)
- Registry engine: [Lycoming VO-540 series](https://openairdocs.org/engine/lycoming-vo-540-series) (registry code 41534, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 2514
- Airframe hours: 6373
- Engines: ALLISON 250-C20B 305 horsepower turbo shaft
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Registered owner: San Joaquin Helicopters
- Airworthiness certificate: Standard, Normal
- Last inspection: 100 hour, June 28, 1983, 29 hours before
- Departed: DLO, DELANO, CA

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 38; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--no waivers/lim.; seat: right; flight hours: 7,000 total, 623 in this make and model, 6,870 as pilot in command, 162 in the last 90 days, 5 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Day
- Wind: calm
- Visibility: 20 statute miles
- Lowest ceiling: none
- Temperature: 73 °F, dew point -0 °F
- Altimeter: 29.00 inHg
- Observed at: VIS, 39 nm away

## FAA reports on this event (1)

The FAA's own accident and incident reports, matched to the aircraft by N-number and date (OpenAirDocs).

- [Accident 19840510017189A](https://openairdocs.org/incident/19840510017189A), May 10, 1984: Hiller STCUH12, Delano, CA, Substantial damage. Engine mounts failed during a spray run. Forced collective up and helicopter landed in the grape arbor.

## Other investigations on N90461 (1)

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

- [NTSB OAK77DVW25](https://openairdocs.org/ntsb/OAK77DVW25), Jul 1, 1977: Hiller 12SL4 (N90461), Bishop, CA, substantial damage

From the NTSB's public API. Aircraft are matched to registry aircraft by N-number and event date, checked against the reported serial number, make and model; the registry's history has gaps, so older matches can be wrong. Compare the reported make and model.

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