N9219F Hughes 369HS accident

NTSB LAX91LA198 · 1991-05-05 · KEANAE, HI

Docket — crew, injuries and powerplant

Factual narrative

DURING AN AIR TAXI SIGHTSEEING FLIGHT THE PILOT EXPERIENCED A SUDDEN TOTAL LOSS OF ALL ENGINE POWER. THE PILOT MADE A FORCED LANDING AND COLLIDED WITH TREES. EXAM OF THE HELICOPTER'S ENGINE REVEALED THE FORWARD SPLINES ON THE SPUR ADAPTER GEARSHAFT HAD FAILED IN FATIGUE WHICH RESULTED IN THE SAG BEING DISCONNECTED FORM THE DRIVE SYSTEM. METALLURGICAL EXAM OF THE FAILED SAG REVEALED IT CONFORMED TO ITS MANUFACTURER'S DESIGN SPECIFICATIONS. THE COMPRESSOR, AND THE SAG, WERE SUBJECT TO AN OVERHAUL 826.8 OPERATIONAL HOURS PRIOR TO THE ACCIDENT.

Probable cause

THE TOTAL FAILURE IN FATIGUE OF THE HELICOPTER'S SPUR ADAPTER GEARSHAFT. A CONTRIBUTING FACTOR WAS RELATED TO THE LACK OF A SUITABLE EMERGENCY LANDING SITE. The National Transportation Safety Board determined the probable cause of this accident.

Circumstances

Event type

Accident

Highest injury

Minor

Weather conditions

Visual Meteorological Cond

Light condition

Day

Sky condition

NONE

Ceiling (ft)

0

Visibility (sm)

20

Wind direction

45

Wind speed (kt)

10

Temperature (F)

79

Distance from field

0.0

Aircraft

Sequence of events

Findings