Hughes 369D N1109V

Summary

On 4 June 2001 at about 02:40 local time, a Hughes 369D registered N1109V was involved in an accident near Hanapepe, Hawaii, United States. 4 people were 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

4 June 2001 at 02:40

Classification

Accident

Location

Hanapepe, Hawaii, United States

Coordinates

21.9500, -159.5500

Aircraft

Hughes 369D

Registration

N1109V

Category

Helicopter

Engines

1

Operator

Not recorded

Operating rule

Part 135: Air Taxi & Commuter

Phase of flight

Not recorded

Route

Hanapepe → Hanapepe

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

LAX01FA200

Nobody was injured.

a loss of engine power while in cruise flight resulting from the failure and liberation of several turbine blades due to hot corrosion effects which weakened the blades. The hot corrosion damage was the result of multiple turbine over temperature events which occurred over several flights. Contributing factors were the lack of suitable terrain, and high vegetation.

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

Read the full NTSB narrative

The helicopter experienced a loss of engine power while in cruise flight. The helicopter was on its way to a rugged area to rescue a person. The pilot indicated that the engine out warning system activated, and he autorotated to a creek after determining that he was unable to manually control the engine power. The pilot performed the autorotation landing to a steep and highly vegetated area. Post-accident examination of the engine revealed its turbine section sustained hot corrosion (sulfidation) damage, which reduced the cross sectional area of the airfoils. The degree of hot corrosion damage suggests that multiple over temperature events occurred over a number of flights. The reduced cross section resulted in the liberation of one or more of the airfoils in tensile overload. The failure of the airfoils resulted in secondary over temperature and failure of other airfoils in the turbine section and eventual turbine seizure. Examination of the TOT thermocouples revealed three of the four leads were broken; however, it could not be determined as to when the fractures occurred.

Quoted verbatim from the NTSB record.