Hiller UH-12E N9762C

Summary

On 29 November 1989 at about 23:30 local time, a Hiller UH-12E registered N9762C, operated by Glacier Helicopters, was involved in an accident near Raymond, Washington, United States. One person was on board and nobody was injured. The aircraft was substantially damaged. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

29 November 1989 at 23:30

Classification

Accident

Location

Raymond, Washington, United States

Coordinates

46.6409, -123.6295

Aircraft

Hiller UH-12E

Registration

N9762C

Category

Helicopter

Engines

1

Operator

Glacier Helicopters

Operating rule

Part 133: Rotorcraft Ext. Load

Purpose of flight

Other Work Use

Phase of flight

Not recorded

Route

Raymond → Unknown

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

SEA90LA025

Nobody was injured.

LOSS OF ENGINE POWER DUE TO FATIGUE FAILURE OF THE IMPELLER. THE HELICOPTER WAS SUBSTANTIALLY DAMAGED AS A RESULT OF A ROLL-OVER ON UNEVEN TERRAIN.

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

Read the full NTSB narrative

DURING AN EXTERNAL LOAD OPERATION, WHILE HAULING A LOAD UPHILL TO THE LANDING ZONE, THE PILOT HEARD A LOUD NOISE AND THE ENGINE BEGAN TO LOSE POWER. THE PILOT RELEASED THE LOAD AND AUTOROTATED TO A LANDING ON INCLINED TERRAIN. WHILE LANDING, THE HELICOPTER ROLLED OVER. DURING AN ENGINE TEARDOWN, A SECTION OF THE IMPELLER WAS FOUND TO HAVE FAILED FROM FATIGUE, WHICH RESULTED IN ADDITIONAL DAMAGE TO THE ENGINE AND A LOSS OF POWER.

Quoted verbatim from the NTSB record.