# NTSB LAX90DVA01: Hiller 12E, N4026G, Huron, CA, October 16, 1989

- Type: NTSB accident investigation
- Classification: Accident · Serious injuries · Final report
- Date: October 16, 1989, 03:30 local (10:30 UTC)
- Place: Huron, CA
- Coordinates: 36.200954, -120.089714 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=36.2010&lon=-120.0897&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Serious injuries
- Injuries: 1 serious, 1 minor
- Status: Completed, report July 22, 1992
- Report: Approved by Office Director
- NTSB case key (mKey): 26556
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX90DVA01
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/26556/pdf
- Page: https://openairdocs.org/ntsb/LAX90DVA01

## Probable cause

THE PILOT FAILED TO PROPERLY PREFLIGHT THE AIRPLANE BEFORE DEPARTING ON THE ACCIDENT FLIGHT AND MISJUDGED THE FLARE DURING THE ENSUING AUTOROTATION. FACTORS RELATING TO THIS ACCIDENT WERE OIL STARVATION AND TOTAL FAILURE OF THE CONNECTING ROD.

## Sequence of events

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

- Loss of engine power(total) - mech failure/malf, cruise
  - engine assembly,connecting rod - failure,total (contributing factor)
  - fluid,oil - starvation (contributing factor)
  - aircraft preflight - inadequate, pilot in command (cause)
- Forced landing, descent - emergency
  - autorotation - performed, pilot in command
- Hard landing, landing - flare/touchdown
  - altitude - misjudged, pilot in command (cause)

## Analysis

THE PILOT COMPLETED AN AERIAL SPRAYING FLIGHT, LANDED AND PICKED UP HIS FLAGMAN TO TRANSPORT HIM TO ANOTHER FIELD. WHILE ENROUTE TO THE FIELD AT ABOUT 50 FT AGL THE HELICOPTER SUSTAINED A TOTAL ENGINE FAILURE. DURING THE ENSUING AUTOROTATION THE PILOT MISJUDGED THE FLARE ALTITUDE AND SUSTAINED A HARD LANDING. THE INVESTIGATION REVEALED THAT THE NO. 3 CONNECTING ROD FAILED DUE TO OIL STARVATION.

## Aircraft

- Registration: [N4026G](https://openairdocs.org/deregistered/N4026G-2017-07-12), registration cancelled 2017-07-12, S/N 5049, built 1978 (OpenAirDocs)
- Reported make and model: HILLER 12E
- Registry model: [Hiller UH-12E](https://openairdocs.org/model/hiller-uh-12e) (registry code 4360122) (OpenAirDocs)
- Registry engine: [Lycoming VO-540 series](https://openairdocs.org/engine/lycoming-vo-540-series) (registry code 41534, reciprocating) (OpenAirDocs)
- Category: Helicopter
- Serial number: 5049
- Airframe hours: 3219
- Engines: LYCOMING VO-540-C2A 305 horsepower reciprocating
- Damage: Substantial damage
- Flight: Aerial application, Part 137
- Operator: Healy, Joseph G., doing business as Huron Ag Helicopters
- Registered owner: Russell W. Spencer
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: 100 hour, October 8, 1989, 58 hours before

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 47; commercial; airplane ratings: multi-engine land, single-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: center; flight hours: 12,500 total, 3,500 in this make and model, 12,000 as pilot in command, 180 in the last 90 days, 65 in the last 30 days, 1 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Night/dark
- Wind: 200° at 4 knots
- Visibility: 7 statute miles
- Lowest ceiling: none
- Temperature: 52 °F, dew point 37 °F
- Altimeter: 29.00 inHg
- Observed at: NLC, 16 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 19891016040739A](https://openairdocs.org/incident/19891016040739A), Oct 16, 1989: Hiller UH12E, Huron, CA, Substantial damage. Engine lost power after loud bang while ferrying copter and flagman to another spray field. Hard ground impact.

## Other investigations on N4026G (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 LAX84LA010](https://openairdocs.org/ntsb/LAX84LA010), Oct 10, 1983: Hiller UH12E (N4026G), Los Banos, 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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