Helicopter crash cause hair in fuel outlet?

Press, 15 July 1982, Page 4

Helicopter crash cause hair in fuel outlet?

Venison recovery operators have been warned not to fill helicopter tanks from jerry cans or other containers.

A report by the Office of Air Accidents Investigation on an aircraft accident says that matted deer hair appeared to be the cause of a forced landing by a helicopter near Nelson late last year. The hair obstructed the main fuel outlet.

The helicopter was carrying 45 kg of fuel when the pilot decided to return to base and refuel. Cruising at about 135 knots and between 65m and 100 m above the ground, the aircraft yawed to the left and lost revolutions, the report said. When power was reduced, revs returned to normal, but dropped again when power was introduced to cross a river to land op rocks and soft sand. The helicopter rolled on landing.” During tests later, when the start pump and main fuel outlet pipe were removed, a wad of matted deer hair was found to be obstructing the main fuel outlet.

“There was no specific evidence to account for the accumulation of deer hair,” the report said, “but it is a general practice for most operators to refuel during field operations from jerry cans and other containers. “Fuel funnels, which at-

tract stray deer hairs while being carried in the helicopters are the probable cause," the report said. “The hairs are later washed into the aircraft’s fuel tank."

An adjacent fuel flow path through the helicopter's start pump gave sufficient fuel flow for the engine on low power.. settings, but the obstruction to the main fuel

outlet to the engine-driven, pump made the engine lose revolutions under load. The report recommended that the Civil Aviation Division advise all users of Hughes 369 helicopters to use the start pump during critical stages of flight, and to investigate the merit of inspections of fuel tank outlet filters.