ASN Wikibase Occurrence # 30796
Last updated: 2 October 2014
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Date:04-JAN-1999
Time:1645
Type:Silhouette image of generic H500 model; specific model in this crash may look slightly different
Hughes 369D
Owner/operator:Hawkins & Powers Aviation
Registration: N5013P
C/n / msn: 610984D
Fatalities:Fatalities: 0 / Occupants: 3
Other fatalities:0
Airplane damage: Substantial
Location:7 miles south of Woodruff, UT -   United States of America
Phase:
Nature:Survey
Departure airport:
Destination airport:
Narrative:
As the helicopter was being maneuvered at low altitude, the pilot heard a series of compressor stalls, accompanied by a rapid decay of rotor rpm. The helicopter struck the ground, spun around and rolled over on its right side. The engine was functionally tested and was 20 horsepower below overhaul specifications. The compressor stalled repeatedly. Compressor disassembly disclosed case liner erosion, most noticeably at the 5th and 6th stages, and the rotating labyrinth seal was missing. After replacing the seal and installing a slave compressor module, the engine tested normal.

The National Transportation Safety Board determines the probable cause(s) of this accident as follows:
A partial loss of engine power due to erosion in the compressor assembly module. Factors were a missing rotating labyrinth seal, the installation of which had not been performed by unknown maintenance personnel.


Sources:
http://www.ntsb.gov/ntsb/brief.asp?ev_id=20001204X00050&key=1


Revision history:

Date/timeContributorUpdates
27-Sep-2008 01:00 ASN archive Added
24-Dec-2009 11:53 harro Updated [Time, Aircraft type, Total occupants, Total fatalities, Location, Country, Nature, Destination airport, Source, Damage, Narrative]
Number of views: 780

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