Airbus took an important step in its evaluation of alternative fuels last week when it flew an A380 test aircraft with one of its engines powered by a synthetic fuel processed from gas.

The Rolls-Royce Trent 900-powered A380 (MSN004) completed the 3h demonstration flight with the gas-to-liquid (GTL) kerosene blended with standard jet fuel between Airbus's Filton and Toulouse plants on 1 February. It comes just ahead of Boeing's biofuel demonstration 747 flight in conjunction with Virgin Atlantic and General Electric between London and Amsterdam later this month.

The A380 took off with an 11t synthetic fuel uplift in a 40% blend of GTL jet fuel provided by Shell International Petroleum. Airbus invited journalists and partners to Filton to witness the departure.

Airbus revealed its GTL project at last year's Dubai air show in conjunction with a team that includes Qatar Airways, Qatar Petroleum, Rolls-Royce and Shell. The path towards the A380 demonstration started in September last year, says Sébastien Remy, head of alternative fuels research programme. "By October we confirmed that flight test aircraft and the GTL were available, and by November a detailed roadmap for the GTL flight was defined," he adds.

The synthetic fuel was supplied for the trial from the GTL pilot plant in Bintulu, Malaysia. GTL will be available in large volumes by 2011 once the Pearl plant in Qatar comes fully on line.

Remy says that GTL's benefits are "attractive for local air quality" , that it should be equivalent to current jet fuel in life-cycle CO2 terms and should have the same characteristics as future biomass to liquid (BTL) synthetic jet fuel. "GTL is therefore a good precursor to BTL. We can cash in on benefits as early as possible and prepare for the emergence of a wider slate of synthetic fuels."

Airbus and its partners will review the flight test data with results expected in a couple of months. Remy says that this is the first step in the creation of a European led industry platform, with Airbus planning to make its first test flight with biofuel next year.

Airbus aims to have a 50% blend GTL fuel approved by next year, with 100% blend approval by 2013. Qatar Airways revenue services with GTL are planned for 2009.

Remy says alternative non-food feedstocks that are renewable and sustainable, such as algae, are expected to reach maturity by around 2015 with aircraft approved to fly with advanced biofuels as early as 2020. "We believe 25% of jet fuel could be alternative fuel by 2025 and 30% could be biofuel by 2030," he says.

According to Robert Nuttall, R-R vice-president market and environmental strategy, the demonstration was flown with production Trent 900 engines which were operated to maximum power on take off with no restriction.

During the flight, checks were made of engine parameters at different flight levels and in holding conditions, of fuel system indications, of engine transients at maximum altitude and descent, and of relight characteristics, he adds.

Source: Flight International