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ASN Wikibase Occurrence # 182403
Last updated: 23 August 2021
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Date:16-DEC-2015
Time:09:42
Type:Silhouette image of generic R44 model; specific model in this crash may look slightly different
Robinson R44 Raven II
Owner/operator:Vertical Solutions Llc
Registration: N255VS
MSN: 13685
Fatalities:Fatalities: 0 / Occupants: 3
Aircraft damage: Substantial
Category:Accident
Location:Valdez Pioneer Field Airport (PAVD), Valdez, AK -   United States of America
Phase: Initial climb
Nature:SU
Departure airport:Valdez, AK (VDZ)
Destination airport:Valdez, AK (VDZ)
Investigating agency: NTSB
Narrative:
The commercial pilot was departing on a power line patrol flight in the helicopter. After liftoff, the pilot hovered the helicopter about 10 ft above ground level (agl) before commencing a left turn, accelerating to about 25 knots, and initiating a climb. As the helicopter climbed through about 20 ft agl, the engine experienced a total loss of power. The pilot performed an autorotation, but the helicopter landed hard, resulting in substantial damage to the fuselage, skids and tail boom.
Review of the accident helicopterís maintenance records revealed that the fuel injection servo had been repaired and reinstalled about 2 hours before the accident flight. During postaccident examination of the fuel injection servo assembly, small amounts of a white, greasy substance were discovered in the†servo assembly. The greasy substance, later identified as DuPont Krytox, is a lubricant used in small amounts and specific locations, during reassembly after overhaul or maintenance of the fuel injection servo assembly.
Inspection of a fuel injection servo from a different helicopter that had been overhauled by the same maintenance facility revealed similar contamination. A representative from the maintenance facility stated that about 6 months before the accident, they had begun using Dupont Krytox, an approved lubricant, but did not realize that it was being used in excess and in locations not approved per the maintenance/service manual.
Due to the improper and excessive use of assembly lubricant and the lack of engine anomalies, it is likely that the lubricant contaminated the fuel injection servo, causing a disruption in fuel flow, which resulted in a total loss of engine power.
Probable Cause: The overhaul facilityís improper and excessive use of an approved lubricant during overhaul of the fuel injection servo, which resulted in a disruption of fuel flow and a total loss of engine power.

Sources:

NTSB
FAA register: http://registry.faa.gov/aircraftinquiry/NNum_Results.aspx?nNumberTxt=255VS

Accident investigation:
cover
  
Investigating agency: NTSB
Status: Investigation completed
Duration:
Download report: Final report
Location


Revision history:

Date/timeContributorUpdates
17-Dec-2015 17:18 Geno Added
18-Dec-2015 19:09 Aerossurance Updated [Time, Phase, Nature, Departure airport, Destination airport, Source, Narrative]
21-Dec-2016 19:30 ASN Update Bot Updated [Time, Damage, Category, Investigating agency]
18-Mar-2017 11:22 Aerossurance Updated [Source, Narrative]
19-Aug-2017 13:54 ASN Update Bot Updated [Operator, Other fatalities, Nature, Departure airport, Destination airport, Source, Narrative]

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