Hiller UH-12E N5360V

Summary

On 7 July 1998 at about 13:15 local time, a Hiller UH-12E registered N5360V was involved in an accident near Eltopia, Washington, United States. One person was on board and one had minor injuries. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

7 July 1998 at 13:15

Classification

Accident

Location

Eltopia, Washington, United States

Coordinates

46.5004, -119.0506

Aircraft

Hiller UH-12E

Registration

N5360V

Category

Helicopter

Engines

1

Operator

Not recorded

Operating rule

Part 137: Agricultural

Purpose of flight

Aerial Application

Phase of flight

Not recorded

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

SEA98LA124

1 person had minor injuries.

Fatigue of the control rotor blade spar and failure of the maintenance inspector to follow the procedures set forth in the airworthiness directive.

Quoted verbatim from the NTSB record. This site does not paraphrase or interpret it.

Read the full NTSB narrative

The pilot reported that he had just taken off to the south. About 30 seconds into the flight, a control paddle departed the helicopter, and control was lost. The helicopter crashed in a cornfield and rolled inverted, after which the pilot exited. Post-crash examination revealed that a flight control rotor blade departed the helicopter. The spar from the blade separated from a fatigue crack, which originated near one of the outboard retention bolt holes and propagated nearly all of the way around the spar on both sides. The NTSB materials laboratory determined that the fatigue cracking initiated from corrosion pitting. FAA Airworthiness Directives in effect at the time of the accident required inspection of the spar tube, cuff, and bolt holes every 100 hours to detect corrosion and cracking in accordance with a Hiller service bulletin. This service bulletin required a visual inspection for corrosion of the inside surface of the cuff and the inner and outer surfaces of the spar tube. This visual inspection was to be followed by a dye-penetrant inspection of the spar and the cuff to detect any cracks. Although logbook entries (of less than four months and 70 hours time in service before the accident) cited compliance with the relevant AD and service bulletin, no evidence was found of dye penetrant residue, zinc chromate primer, or the required sealant material during NTSB materials laboratory testing.

Quoted verbatim from the NTSB record.