According to one of the key findings from the Air New Zealand Boeing 747-400 Rolls-Royce powered test flight last year, up to 1.4 tonnes of fuel can be saved on a twelve-hour long haul flight powered by a 50/50 blend of second generation jatropha sustainable biofuel and traditional Jet A1.The test flight, a joint initiative between Air New Zealand, Boeing, Rolls-Royce and Honeywell’s UOP, was carried out on 30 December as part of a drive for more sustainable air travel.
The biofuel test programme included extensive on-the-ground and inflight tests of the engine and aircraft components. During the comprehensive flight test, analysis was carried out at various altitudes and under a variety of operating conditions to measure the biofuel’s performance through the engine and fuel systems.
A report prepared by Air New Zealand, Boeing and Rolls-Royce to analyse the data collected throughout the flight says the biofuel selected has demonstrated the potential for use as a drop in replacement to Jet A1 at a blend ratio of up to 50:50. This material now needs to be submitted to the rigorous industry evaluation and approval protocol to enable it to be certified for everyday use.
The report also found that the biofuel’s properties offer some performance improvements over Jet A1 due to its higher net heat of combustion including:
Using this biofuel blend, the fuel burn for a Boeing 747-400 aircraft twelve-hour flight (5800 nautical miles) would improve by 1.2 %, saving 1.43 tonnes of fuel.
Such a reduction in fuel burn would result in a significant reduction in carbon emissions, saving approximately 4.5 tonnes of CO2.
At shorter ranges, fuel burn will improve by 1% when using a mix of 50% biofuel to 50 % Jet A1.
Overall savings due to these hydrotreated bio-derived jet fuels from naturally occurring oils is estimated to be a 60-65% reduction in greenhouse gas (GHG) emissions relative to petroleum-derived jet fuel.
The report says the test flight has demonstrated that more sustainable air travel can be achieved by refiners, airframe manufacturers, engine makers and airlines working together. It should also give those drafting fuel certification regulations more confidence to push ahead and reduce the timeline for certification of a bio-derived drop-in jet fuel to occur.
Air New Zealand General Manager Airline Operations and Chief Pilot Captain David Morgan said it was Air New Zealand’s goal to become the world’s most environmentally sustainable airline, and that it was proud to have played an important role in furthering the industry’s body of knowledge on sustainable alternative biofuels.
“We currently have a team looking at several different biofuel options. We remain committed to our ambition of having 10% of our fuel needs by 2013 met by alternative fuels, but appreciate there are many more steps to be taken by experts in other areas to deliver biofuel as a commercial aviation fuel source,” he said.