Robinson R44 II N255VS

Summary

On 16 December 2015 at about 18:42 local time, a Robinson R44 II registered N255VS, operated by Vertical Solutions LLC, was involved in an accident near Valdez, Alaska, United States. 3 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

16 December 2015 at 18:42

Classification

Accident

Location

Valdez, Alaska, United States

Nearest airport

Valdez Pioneer Field (VDZ)

Coordinates

61.1342, -146.2447

Aircraft

Robinson R44 II

Registration

N255VS

Category

Helicopter

Year built

2014

Engines

1

Operator

Vertical Solutions LLC

Operating rule

Part 91: General Aviation

Purpose of flight

Aerial Observation

Phase of flight

Not recorded

Route

Valdez → Valdez

Aircraft damage

Substantial

Weather

VMC

Light

Day

NTSB number

ANC16LA010

Nobody was injured.

The overhaul facility’s 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.

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

Read the full 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 helicopter's 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.

Quoted verbatim from the NTSB record.