In an attempt to reduce its fuel bill and limit its carbon footprint, Air New Zealand successfully tested a new vegetable oil biofuel during a two-hour trial flight earlier in the week.

The flight "milestone" involved using a 50-50 mixture of jatropha oil -- made from a plum-sized fruit -- with regular jet A1 fuel in one engine of a Boeing 747-400 aircraft.  The biofuel industry has also shown a strong interest in using grass, algae and halophytes as possible biofuels.

"There's still a lot of analysis to be done but we achieved a lot with the test flight and the maneuvers we've done," Air New Zealand pilot Captain Dave Morgan told the New Zealand Herald.  "The aircraft performed flawlessly."

Despite a stronger movement to use biofuels to power cars, airline companies have been working with jet manufacturers to try and integrate biofuels for commercial flights.  Last February, Virgin Atlantic tested a flight with a mixture of Brazilian nuts and coconuts with regular jet fuel.  Continental Airlines plans to test a flight using a 50-50 mix of traditional jet fuel along with algae and jatropha.

Aviation industry insiders indicate it'll be easier to convert planes to biofuels when compared to cars, trucks and other land vehicles -- the infrastructure would involve only a few hundred fueling station, rather than the millions that would be required.  Critics say airliners relying on biofuels could help increase deforestation in the Amazon rain jungles, and could lead to food prices increasing further in the future.

Airline companies were hit hard in 2008 by skyrocketing oil prices and must now prepare for less air travelers due to the struggling economy.  Expect both jet manufacturers and airline companies to work together to in the future to hasten the adoption of biofuels.

This is first stage in ANZ's attempt to utilize sustainable fuel development, and it's unknown when the company plans to launch further tests.