# NTSB LAX86FVA14: Hiller UH-12E, N688SB, Lemoore, CA, September 18, 1986

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Final report
- Date: September 18, 1986, 05:30 local (12:30 UTC)
- Place: Lemoore, CA
- Coordinates: 36.290882, -119.819145 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=36.2909&lon=-119.8191&mi=10
- Phase of flight: [Enroute](https://openairdocs.org/ntsb-phases/400) (OpenAirDocs' grouping)
- Highest injury: Minor injuries
- Injuries: 1 minor
- Status: Completed
- Report: Approved by Office Director
- NTSB case key (mKey): 24965
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX86FVA14
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/24965/pdf
- Page: https://openairdocs.org/ntsb/LAX86FVA14

## Sequence of events

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

- Airframe/component/system failure/malfunction, cruise - normal
  - engine assembly,connecting rod - failure,total (cause)
  - engine assembly,connecting rod - overload
  - maintenance,overhaul - improper, other maintenance personnel (cause)
- Forced landing, descent - emergency
  - autorotation - performed, pilot in command
- In flight collision with terrain/water, landing - flare/touchdown

## Analysis

THE PLT REPTD THAT WHILE RETURNING TO THE LOADING AREA AFTER SPRAYING A FIELD, HE HEARD A LOUD POP EMANATING FROM THE ENGINE COMPARTMENT. SHORTLY THEREAFTER HE OBSERVED A FIRE IN THE ENGINE COMPARTMENT AND LOST FORWARD AND AFT CONTROL OF THE HELICOPTER. THE PLT IMMEDIATELY EXECUTED AN AUTOROTATION. THE HELICOPTER ROLLED OVER ONTO ITS SIDE ON TOUCH DOWN. THE POST-ACCIDENT INVESTIGATION ENGINE EXAMINATION DISCLOSED THAT THE NUMBER 3 CONNECTING ROD BOLTS FAILED. FURTHER EXAMINATION REVEALED THAT THE REMAINING CON ROD BOLTS TORQUE VALUES WERE ABT 50% LESS THAN THE REQUIRED VALUES.

## Aircraft

- Registration: [N688SB](https://openairdocs.org/deregistered/N688SB-1989-09-14), registration cancelled 1989-09-14, S/N 1825 (OpenAirDocs)
- Reported make and model: HILLER UH-12E
- Registry model: [Hiller UH-12E](https://openairdocs.org/model/hiller-uh-12e) (registry code 4360122) (OpenAirDocs)
- Category: Helicopter
- Serial number: 1825
- Engines: LYCOMING VO-540-C2A 305 horsepower reciprocating
- Damage: Substantial damage
- Fire: Both
- Flight: Aerial application, Part 137
- Operator: West Farm Air
- Registered owner: James P. Smith
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: 100 hour, August 18, 1986, 51 hours before
- Airport: NLC, Lemore Nas

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 41; commercial; airplane ratings: single-engine land; medical: class 2, valid medical--w/ waivers/lim; seat: right; flight hours: 5,000 total, 3,003 in this make and model, 5,000 as pilot in command, 150 in the last 90 days, 4 in the last 24 hours

## Weather

- Conditions: Visual (VMC), Night/dark
- Visibility: 7 statute miles
- Lowest ceiling: none

## 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 19860918045429A](https://openairdocs.org/incident/19860918045429A), Sep 18, 1986: Hiller UH12E, Lemoore, CA, Substantial damage. The engine failed and caught fire causing ahard forced landing. Rod bolts were found to be improperly torques.

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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