Interesting: Fuel tank contamination found in crash probe

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Thursday, April 13, 2006 11:30 AM

http://www.mauinews.com/story.aspx?id=18672

Fuel tank contamination found in crash probe

KAHULUI – The fuel tank of a Windward Aviation helicopter that made

a forced landing at McGregor Point on May 16 was contaminated with a

fungus that thrives in water that can collect in fuel mixtures,

according to a federal investigation.

A factual report filed by the National Transportation Safety Board

this week said the helicopter company had complied with an

airworthiness directive for dealing with the problem of fuel

contamination by cleaning fuel screens and nozzles.

But maintenance personnel had not opened and cleaned the fuel tank

itself, the NTSB report said.

The report was on an emergency landing made by a Windward Aviation

369D helicopter, piloted by company owner Don Shearer with

three passengers.

No one was injured when Shearer landed on the rocks along the

shoreline after the engine lost power while the helicopter was 500

feet above McGregor Point.

The helicopter was reported to have suffered substantial damage.

The NTSB report noted that the helicopter had been used on Kauai on

May 12 and 13, during which time it was refueled from a remote fuel

tank that had a damaged cover and was not checked properly for

contaminants.

On a flight back to Maui, the helicopter was refueled on Oahu, but

the engine would not start and the pilot discovered " brown watery

contamination " in the fuel. A maintenance crew purged and cleaned

the fuel system, and replaced the fuel nozzle and filters.

But maintenance crew members said they did not open and clean the

fuel tank.

The report said there is a potential for microscopic fungi growth in

water that contaminates diesel and jet fuel.

" The fungi will grow rapidly, requiring only trace amounts of water

and minerals for sustainability. Once this growth begins, the fungi

turns into a type of slime, " the report said.

" As they grow, the fungi will chemically alter the fuel to produce

water, sludge and acidic byproducts. A myriad of problems within the

fuel system can occur, including clogging of the various fuel

filters and fuel system components. "

The report said there were three prior incidents in Hawaii involving

fuel contamination that led to one death and four serious injuries,

with one helicopter destroyed and two others seriously damaged.

The NTSB issued an airworthiness directive on Jan. 5, 2005, on

inspections and cleaning required when fuel system contamination

occurs. Windward Aviation had complied with the directive, the

report said.

When the fuel tanks of the disabled helicopter were examined, the

NTSB report said investigators found the sides and bottom of the

tanks were coated with a " brownish watery substance " that also was

found on a fuel pump screen and a fuel outlet line.