Radio New Zealand - Te Reo Irirangi o Aotearoa

Air New Zealand says it has completed preparations for a two-hour test flight by a Boeing 747-400 with one engine powered by a biofuel blended with standard jet fuel.

A Boeing 747-400 powered by Rolls-Royce RB211 engines will do a test flight from Auckland International Airport over the Hauraki Gulf next Wednesday.

The fuel has been blended 50-50 with standard jet fuel and is known as J50, or jatropha.

Only one of the plane's four engines will use the fuel.

The airline says a number of tests will be carried out to "measure the performance of the engine and fuel systems at various altitudes and under a variety of operating conditions".