Biofuel flight report shows fuel-saving potential
Data from an Air New Zealand test flight shows that up to 1.4 tonnes of fuel could be saved on a 12-hour long-haul flight powered by a biofuel blend.
The result is one of the key findings from the flight in December last year, using a Boeing 747-400 with Rolls-Royce engines. One of the four engines ran on a 50:50 blend of second generation jatropha biofuel and traditional Jet A1.
Air New Zealand general manager airline operations and chief pilot Captain David Morgan announced the scientific findings from the test flight at the Eco-Aviation Conference in Washington.
The test flight, a joint initiative between Air New Zealand, Boeing, Rolls-Royce and Honeywell's UOP, was carried out on 30 December and used the highest blend of any type of biofuel in a test flight.
The 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 from 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 per cent, 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 per cent when using a mix of 50 per cent biofuel to 50 per cent Jet A1.
> Using these hydrotreated bio-derived jet fuels would lead to an estimated 60-65 per cent 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 through collaboration between refiners, airframe manufacturers, engine makers and airlines. 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.
The partners will publish their data to various industry bodies to contribute to the current programme evaluating this and similar fuel products as potential alternatives to Jet A1.
Captain Morgan said it was Air New Zealand's goal to become the world's most environmentally sustainable airline. "We currently have a team looking at several different biofuel options," he commented. "We remain committed to our ambition of having 10 per cent 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."
Air New Zealand complete biofuel test flight
Published on 2 January 2009