NTSB Identification: LAX97LA176.
The docket is stored in the Docket Management System (DMS). Please contact Records Management Division
Accident occurred Saturday, May 10, 1997 in PUAKO, HI
Probable Cause Approval Date: 12/31/1998
Aircraft: Hughes 369D, registration: N5105N
Injuries: 2 Fatal,2 Serious.
NTSB investigators may not have traveled in support of this investigation and used data provided by various sources to prepare this aircraft accident report.
The helicopter was cruising at low level when the engine failed. The pilot turned toward a landing area and entered an autorotation with a quartering tailwind. During the autorotation, the helicopter continued to descend, remaining in a nose low attitude, until striking the ground. Impact occurred on up sloping terrain, and the helicopter was damaged. A computation of the weight and balance revealed the helicopter's moment arm exceeded the forward CG limit by about one inch, and limited aft cyclic control. An examination of the engine revealed that a stator vane had failed due to excessive erosion and fatigue cracking. The condition had not been detected during a compressor case erosion inspection, 60 flight hours before the accident.
The National Transportation Safety Board determines the probable cause(s) of this accident to be: erosion of second stage stator vanes, inadequate maintenance inspection for the erosion, and subsequent fatigue failure of a stator vane, which resulted in loss of engine power and a forced landing on mountainous/hilly terrain. Also causal was: the pilot's loading of the aircraft in such a manner that exceeded the forward CG limit, which resulted in his failure (or inability) to properly flare the helicopter during a forced autorotation and landing. The rising terrain and tailwind condition for landing were related factors. Full narrative available
Index for May1997 | Index of months