Date:	Saturday 19 August 1989
Time:	09:10
Type:	Aérospatiale AS 350D
Owner/operator:	Papillon Hawaiian Tours
Registration:	N35970
MSN:	1131
Total airframe hrs:	8833 hours
Engine model:	Lycoming LTS-101
Fatalities:	Fatalities: 0 / Occupants: 7
Other fatalities:	0
Aircraft damage:	Destroyed
Category:	Accident
Location:	Volcano, Hawaii County, District of Puna, Hawaii -   United States of America
Phase:	Landing
Nature:	Private
Departure airport:	Waikoloa, Hawaii
Destination airport:
Investigating agency:	NTSB
Confidence Rating:	Accident investigation report completed and information captured

Narrative:
THE VFR SIGHT-SEEING FLIGHT WAS BEING CONDUCTED UNDER 14 CFR 135. WHILE DESCENDING INTO A MOUNTAINOUS AREA THE PILOT FELT A SEVERE VIBRATION ABOUT 10-15 SECONDS BEFORE THE ENGINE FAILED. THE PILOT EXECUTED AN AUTOROTATION IN THE UPWARD SLOPING TERRAIN AND THE HELICOPTER ROLLED-OVER ON TOUCHDOWN.

THE ENGINE EXAM DISCLOSED THAT THE POWER TURBINE SHAFT AND THE NOS. 2 & 3 BEARINGS FAILED DUE TO OIL STARVATION AND DISPLAYED EXTREME HIGH TEMPERATURE DISTRESS. THE CHIP DETECTOR O-RING SEAL WAS EXCESSIVELY WORN. OIL RESIDUE STREAKING WAS FOUND ON THE OUTSIDE OF THE FUSELAGE/ TAILCONE ASSEMBLY AND THE VERTICAL/HORIZONTAL STABILIZERS

PROBABLE CAUSE:A CATASTROPHIC FAILURE OF THE POWER TURBINE SHAFT AND BEARINGS. THE FAILURE WAS A RESULT OF OIL STARVATION DUE TO AN EXCESSIVELY WORN CHIP DETECTOR O-RING SEAL, INADEQUATE MAINTENANCE AND PRE-FLIGHT. CONTRIBUTING FACTOR(S) WAS: THE MOUNTAINOUS TERRAIN.

1. FAA: https://www.ntsb.gov/aviationquery/brief.aspx?ev_id=20001213X29162&key=1
2. NTSB: http://registry.faa.gov/aircraftinquiry/NNum_Results.aspx?omni=Home-N-Number&nNumberTxt=35970
3. http://www.griffin-helicopters.co.uk/accidentdetails.aspx?accidentkey=11560
4. [LINK NOT WORKING ANYMORE:http://coptercrazy.brinkster.net/search/se350show.asp?start=101&count=50]
5. https://en.wikipedia.org/wiki/Volcano,_Hawaii

Date/time	Contributor	Updates
30-Jun-2014 20:47	Dr. John Smith	Updated [Time, Location, Nature, Departure airport, Source, Narrative, ]
21-Dec-2016 19:25	ASN Update Bot	Updated [Time, Damage, Category, Investigating agency, ]