Smiles plastered across the emerging pilots' faces and fists punching the air, the sight said everything about Air New Zealand's first commercial test flight powered by a biofuel success.

The airline's chief executive, Ron Fyfe, greeted his two pilots with a joyous handshake before turning to the international media gathered on the runway to reiterate the significance of the morning's exercise.

"We are very proud at Air New Zealand and today what we have done with our partners is to chart a new course for the aviation industry the first step in making biofuels commercially viable," he said.

"It represents one plank in our goal to become the most environmentally sustainable airline in the aviation industry."

Moments earlier, a Boeing 747-400, with one of its four engines powered by a 50:50 mix of the oily nut from the jatropha tree and traditional Jet A1 fuel, had touched down at Auckland International Airport after completing a two-hour test flight.

During that time Air New Zealand's chief pilot, Dave Morgan, and pilot in command Keith Pattie put the jumbo through a series of stringent tests at different altitudes and speeds to assess the jatropha fuel's performance.

During the next few days engineers will assess the plane's engine and fuel systems, looking for any unwanted side-effects because of using the biofuel.

Some of the blended fuel will then be sent to the United States and Britain for further testing and, if all goes well, certification. Then begins the long road to production, during which the commercial viability of the alternative fuel will be intensely investigated.

"This is a 30-year journey, not a five or 10-year transformation," said Jennifer Holmgren, general manager of renewable energy and chemicals at Honeywell's UOP, which is a partner in the joint initiative, along with Boeing and Rolls-Royce.

Ms Holmgren said it was highly unlikely any large-scale production would get off the ground before 2012. While the fuel obviously worked as an excellent drop-in replacement to Jet A1, she said the full production cost was still unknown.

Rolls-Royce fuels specialist Chris Lewis said jatropha biofuel was "virtually indistinguishable" from Jet A1 fuel.

Air New Zealand said it expected biofuel to make up 10 per cent of its total fuel burn of 9 million barrels a year by 2013, reducing its carbon footprint by 400,000 tonnes a year.

It was the first airline in the world to set such a target.

Source stuff.co.nz