A big day out for Kapiti Heliworx

LONG HAUL: Kapiti Heliworx gets ready to lift a rodent trap from Waikanae to the Marlborough Sounds.

Kapiti Heliworx had a unique yet challenging job on Monday.

Pilot Dennis Young airlifted a supersized rodent trap from the Waikanae River estuary to an isolated part of Resolution Bay at the top of the Marlborough Sounds.

The trap, weighing more than 400kg, and looking like a spa pool, was manufactured by a company in Hastings for the Conservation Department.

"It's an experimental device."

He said the trap doesn't kill rodents as such. It looks like more of a holding pen".

"If you can imagine a big spa pool, with eight sides, and at the bottom of each side is a small door that the rodents will enter and there's some contraption that stops them from walking out.

"It has got an open top but it's too high for them to get out because there's nothing to grab onto."

Trial flights were conducted to gauge the amount of fuel and necessary speed for the 75km straight line flight in a Bell 206 Jet Ranger. Plywood was also secured over the trap top which made it easier to move, and doors and seating removed to lighten the load.

"It was a very cold trip. I was shaking by the time I got down there."

Placing the trap, which was connected to the chopper on a very long line, needed pinpoint accuracy.

"It was down a hole among some trees."

Mr Young said the trap trip was the most challenging operation Heliworx had been involved with.