Hughes 269C N9609F

Summary

On 25 September 1992 at about 16:10 local time, a Hughes 269C registered N9609F, operated by Helicopters, Inc., was involved in an accident near East Bernstadt, Kentucky, United States. 2 people were on board and 2 died. The aircraft was destroyed. The NTSB has published a probable cause for this accident; it is quoted in full below.

Date

25 September 1992 at 16:10

Classification

Accident

Location

East Bernstadt, Kentucky, United States

Coordinates

37.1802, -84.1105

Aircraft

Hughes 269C

Registration

N9609F

Category

Helicopter

Engines

1

Operator

Helicopters, Inc.

Operating rule

Part 91: General Aviation

Purpose of flight

Aerial Observation

Phase of flight

Not recorded

Route

Winchester → Unknown

Aircraft damage

Destroyed

Weather

VMC

Light

Day

NTSB number

BFO92FA144

2 people died.

INADEQUATE MAINTENANCE INSPECTION INVOLVING FAILURE TO DETECT WEAR OF THE CLUTCH SPRING ASSEMBLY, RESULTING IN THE UNCOUPLING OF ENGINE POWER TO THE MAIN TRANSMISSION.

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

Read the full NTSB narrative

THE HELICOPTER WAS ON A LOW ALTITUDE POWERLINE PATROL WHEN IT DESCENDED AND COLLIDED WITH UPSLOPING TERRAIN. THE INVESTIGATION REVEALED THE CLUTCH SPRING ASSEMBLY WAS FRACTURED, INVOLVING THE ASSEMBLY RETAINER END WHICH SEPARATED. THE RETAINER WALL WAS SEVERELY WORN WHERE THE SEPARATION OCCURRED. THE ASSEMBLY FUNCTIONS TO ENGAGE THE BELT DRIVE SYSTEM WHICH IN TURNS TRANSMITS ENGINE POWER TO THE MAIN TRANSMISSION. THE HELICOPTER HAD OVER 11,000 HOUR OF TOTAL TIME. THE LAST INSPECTION OF THE ASSEMBLY WAS ABOUT A MONTH EARLIER, DURING A 100 HOUR INSPECTION. A REVIEW OF MAINTENANCE RECORDS REVEALED NO PREVIOUS REPLACEMENT OF THE ASSEMBLY.

Quoted verbatim from the NTSB record.