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LAX84LA494 · Hiller UH12ET

25 Sept 1984 · Yuma, AZ, United States

Hiller UH12ET · Accident: airframe, component or system failure while maneuvering

From Yuma, AZ to an unrecorded destination

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Event

NTSB case
LAX84LA494
Event typeAccident: someone killed or seriously injured, or the aircraft substantially damaged (NTSB definition). Incident: an occurrence that affected or could have affected safety, short of that. Glossary
Accident
InvestigationHow far the investigation had got when the record was published: preliminary, ongoing, final or completed. Unknown where the source does not say. Glossary
Completed
API-reported fatalities
0 · all aircraft and ground
Ground fatalities
0
OperationWhat kind of flying it was, grouped by the rules it flew under: airline (US Part 121), air taxi and commuter (Part 135), general aviation (Part 91 and similar), military or government. Glossary
General aviation
WeatherVisual meteorological conditions (VMC): good enough to fly by looking outside. Instrument conditions (IMC): cloud or low visibility, flying by instruments. Glossary
Visual Meteorological Cond

Hiller UH12ET

Aircraft type
Hiller UH12
Category
Helicopter
RegistrationThe aircraft's tail number, such as N12345 or G-ABCD. Registrations are reissued, so the same one years apart can be a different aircraft. Glossary
N9278Z
Operator
Unknown
Onboard fatalities
Unknown
Route
From Yuma, AZTo not recorded
Aircraft age
Not recorded
Flight rulesThe regulations the flight operated under: in the US, Part 91 (general aviation), Part 121 (airlines), Part 135 (air taxi and commuter) and others; for flights abroad, the NTSB's coarser commercial or non-commercial code. Glossary
Part 137: Agricultural
Phase of flightThe stage of the flight when things started to go wrong: standing, taxi, takeoff, initial climb, en route, maneuvering, approach or landing. Glossary
Maneuvering · aerial application
First occurrenceThe single coded event the NTSB judges best describes what happened (records from 2008 on). Older records name the first occurrence in the sequence instead. Glossary
Airframe, component or system failure
DamageDestroyed: beyond practical repair. Substantial: damage that affects the structure, performance or handling and normally needs major repair. Minor: less than that. Glossary
Destroyed

Cause areas

  • Company maintenance personnel › Maintenance, compliance with ad, not performed
  • Rotor system, main rotor blade spar › Corroded
  • Rotor system, main rotor blade spar › Failure, total

Approximate · Estimated position: the centre of Yuma, AZ, the place the record names. Not the accident site.

NTSB narrative

THE PILOT STATED THAT HE WAS CARRYING A LOAD OF PESTICIDE FOR APPLICATION ON A BROCCOLI FIELD. THE AIRCRAFT WAS IN LEVEL FLIGHT, APPROXIMATELY 4 TO 8 FEET AGL WHEN IT BECAME UNCONTROLLABLE AND IMPACTED THE GROUND. THE AIRCRAFT WAS CONSUMED BY A POST CRASH FIRE. EXAMINATION OF THE AIRCRAFT AFTER THE ACCIDENT REVEALED THAT ONE OF THE TWO MAIN ROTOR BLADES HAD SEPARATED IN-FLIGHT. EXAMINATION OF THE SEPARATED ROTOR BLADE REVEALED A FATIGUE TYPE FRACTURE OF THE MAIN ROTOR BLADE SPAR TUBE THROUGH THE OUTBOARD RETENTION BOLT HOLES. THE FAILED MAIN ROTOR BLADE SPAR BORE EVIDENCE OF CORROSION. THE MAIN ROTOR BLADE CUFF WAS THE SUBJECT OF AN AIRWORTHINESS DIRECTIVE THAT ACCORDING TO THE AIRCRAFT LOGBOOKS HAD BEEN COMPLIED WITH AS REQUIRED. THE LAST THREE LOGBOOK NOTATIONS, DOCUMENTING COMPLIANCE WITH THE AD, WERE ENTERED AFTER THE ACCIDENT.

Verbatim NTSB analysis from the NTSB dataset

Sources

NTSB record LAX84LA494
Event ID
20001214X41132
Case number
LAX84LA494
Dataset
historical-pre2008
Source SHA-256
89e2df6d848e7ab3b42e7d7c7a03ff403303057a26ca04c95b3ea67201c3ce74
Source notes (4)
  • Unreviewed is an editorial label, not an investigation status. API-sourced is not report-checked or human-reviewed. Explicit event totals are used without summing aircraft injury tables; onboard allocation is withheld. Unknown values remain unknown. The operation category is mapped from the NTSB-reported FAR part and has not been reviewed.
  • Filled from the NTSB case API where the bulk record had no value: investigation status. Values present in the bulk record are kept.
  • The date is the local date, which is the same as the UTC date the NTSB stores.
  • API snapshot SHA-256: 5cfd5cc4391212074c71af248fe546eee6ad18e8e8eeff2865395ff6aca4f552; retrieved 2026-09-21T17:26:34.952Z.