The world's first commercial aviation test flight of a sustainable "second-generation" biofuel will be limited to a 50% blend to prevent engine leakage.

The biofuel blend, named J50, will be used to power one Rolls-Royce RB211 engine on an Air New Zealand Boeing 747-400 for a 2h test flight scheduled to take off from Auckland airport on 3 December.

 © flcriminal/AirSpace

The blend, which comprises jatropha fuel and an equal quantity of standard Jet A1 kerosene to maintain the fuel mix's aromatic profile, was created by ANZ at its Auckland engineering base. The hydrogenated oil fuel type refined by Honeywell subsidiary UOP does not have the aromatic content needed to prevent engine seals from shrinking slightly and, depending on their condition, from leaking.

Energy density however is 4% higher than petroleum, meaning the jatropha blend has 4% more range, or in a given range requires 4% less fuel.

Source: Flight International