# NTSB LAX86FVM05: Hiller UH12E, N5374V, Castroville, CA, April 27, 1986

- Type: NTSB accident investigation
- Classification: Accident · Minor injuries · Final report
- Date: April 27, 1986, 05:30 local (12:30 UTC)
- Place: Castroville, CA
- Coordinates: 36.759407, -121.749786 (estimated)
- Nearby events: https://openairdocs.org/map.md?lat=36.7594&lon=-121.7498&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): 24985
- NTSB case page: https://web.ntsb.gov/investigations/?ntsbnumber=LAX86FVM05
- NTSB report (PDF, downloads): https://data.ntsb.gov/carol-repgen/api/Aviation/ReportMain/GenerateNewestReport/24985/pdf
- Page: https://openairdocs.org/ntsb/LAX86FVM05

## Sequence of events

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

- Airframe/component/system failure/malfunction, cruise - normal
  - rotor system,tail rotor blade - overload (cause)
  - rotor system,tail rotor blade - failure,total (cause)
  - rotor system,tail rotor blade - separation (cause)
- Forced landing, descent - emergency
- Hard landing, landing - flare/touchdown
- Roll over, landing - flare/touchdown
  - landing gear,main gear strut - failure,total (cause)

## Analysis

THE ACFT LANDED HARD AND ROLLED OVER AFTER THE LNDG SKID FAILED IN A FORCED LNDG. THE PLT SAID HE WAS CRUSING AT 500 FT AGL OVER AN OPEN FIELD WHEN HE HEARD A LOUD BANG. THE HELICOPTER BEGAN TO VIBRATE SEVERELY AND SPIRAL TO THE RIGHT. THE PLT LOST GROUND REFERENCE IN THE PRE-DAWN DARKNESS WHEN HE TURNED ON THE LIGHTS. NOT WANTING TO LAND TOO HARD HE ELECTED TO LEAVE THE ENG RUNNING AND NOT AUTO-ROTATE. INVESTIGATION INDICATED THAT ONE TAIL ROTOR BLADE HAD SEPARATED AT THE TENSION TORSION STRAP ATTACH BOLT HOLE. THIS IS THE TRANSITION AREA WHERE THE BLADE ROOT CASTING AND SHEET METAL BLADE SKIN ARE JOINED. THE FRACTURE SURFACE OF THE CASTING APPEARED TO BE OVERLOADED WITH NO APPARENT INDICATION OF FATIGUE. THE OUTBOARD BLADE SECTION SHOWED NO INDICATION OF FOREIGN OBJECT CONTACT. ALL COMPONENTS OF THE HELICOPTER WERE LOCATED IN THE IMPACT AREA EXCEPT ONE TAIL ROTOR BLADE.

## Aircraft

- Registration: [N5374V](https://openairdocs.org/aircraft/N5374V), registered now, S/N 2073, built 1961 (OpenAirDocs)
- Reported make and model: HILLER UH12E
- 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: 2073
- Airframe hours: 7563
- Engines: ALLISON 250-C20 385 horsepower turbo shaft
- Damage: Destroyed
- Flight: Aerial application, Part 137
- Operator: Douglas E. Walker, doing business as Pilot Civilian
- Registered owner: Verticare Inc.
- Airworthiness certificate: Special, Restricted (Special)
- Last inspection: 100 hour, July 1, 1985, 42 hours before
- Departed: CASTROVILLE, CA
- Destination: SALINAS, CA
- Airport: SNS, Salinas

## Flight crew

As NTSB recorded them. NTSB leaves out names.

- Pilot; age 31; commercial; airplane ratings: multi-engine land; instrument ratings: airplane; medical: class 2, valid medical--no waivers/lim.; seat: center; flight hours: 2,000 in this make and model

## Weather

- Conditions: Visual (VMC), Night/dark
- Wind: calm
- Visibility: 25 statute miles
- Lowest ceiling: none
- Temperature: 45 °F, dew point 39 °F
- Altimeter: 30.00 inHg
- Observed at: SNS

## 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 19860427016079A](https://openairdocs.org/incident/19860427016079A), Apr 27, 1986: Hiller UH12E, Castroville, CA, Destroyed. Tail rotor blade separated at tension tortion strap attach bolt. Made power on landing but hit hard and rolled over.

## Other investigations on N5374V (2)

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 LAX00LA027](https://openairdocs.org/ntsb/LAX00LA027), Oct 28, 1999: Hiller UH-12E (N5374V), Castroville, CA, substantial damage. Probable cause: The pilot's inadequate visual lookout and diverted attention.
- [NTSB LAX74FUM09](https://openairdocs.org/ntsb/LAX74FUM09), Oct 19, 1973: Hiller Acft UH-12E (N5374V), El Centro, CA, destroyed

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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