High-fat flight is the first jetliner to make fossil fuel-free flight from London to New York

The first commercial fossil fuel-free airliner to cross the Atlantic on purely high-fat, low-emissions fuel has flown from London to New York in a step toward achieving what supporters called "jet zero."

The Virgin Atlantic Boeing 787 flight relied on Sustainable Aviation Fuel made up largely of tallow and other waste fats.

"The world will always assume something can't be done, until you do it," said Virgin founder Richard Branson. 

Mr Branson was joined on the flight by corporate and government officials, engineers and journalists.

The UK Transport Department provided 1 million pounds ($1.9 million) to plan and operate the flight. 

The department called the test a "huge step towards jet zero" to make air travel more environmentally friendly. 

But large hurdles remain in making the fuel widely available.

High cost and tight supply remains a barrier

The high cost and tight supply of materials needed to make Sustainable Aviation Fuel make large-scale production difficult.

SAF accounts for less than 0.1 per cent of total global jet fuel in use today and costs three to five times as much as regular jet fuel.

SAF reduces greenhouse gas emissions by about 70 per cent and is the best near-term way for the international aviation industry to achieve its net zero target by 2050, the US Energy Department said, though it called the goal aspirational.

There is a goal of producing 1 billion gallons (approximately 3 billion litres) a year set in 2018 by the Federal Aviation Administration.

The White House, meanwhile, set a goal two years ago to produce 3 billion gallons (approximately 6 billion litres) of sustainable aviation fuel per year by 2030. 

The UK has set a goal that 10 per cent of jet fuel will come from sustainable sources by 2030.

"It's going to take a while before we can get enough fuel where everybody's going to be able to fly. But you've got to start somewhere," Mr Branson said. 

Holly Boyd-Boland, vice president of corporate development at Virgin Atlantic, said the flight shows that the fuel can power existing aircraft.

The challenge she said, is ramping up production to "get to enough volume so that we're flying more sustainable aviation fuel every day."

"If you hadn't known it was a 100 per cent SAF flight, no one would have noticed," UK Transport Minister Mark Harper said. 

He and US Transportation Secretary Polly Trottenberg plan to meet on Wednesday with the investor community in New York "about what they look for when they invest in SAF production  are there any barriers, are there any market failures, are there things governments need to do to help get this stuff over the line."

'Misleading claims'

The group Aviation Environment Federation said the aviation industry was making misleading claims about the impact of sustainable fuel on carbon emissions.

"The idea that this flight somehow gets us closer to guilt-free flying is a joke," said policy director Cait Hewitt.

She said sustainable aviation fuel  "will be very hard to scale up sustainably."

While this is the first jetliner to make the trans-Atlantic journey using only the sustainable fuel, it was not a commercial flight and not the first jet to do so.

Gulfstream Aerospace was the first to make the crossing earlier this month with a business jet powered only by the eco-fuel.

Air France-KLM flew from Paris to Montreal two years ago using a mix of petroleum-based jet fuel and a synthetic derived from waste cooking oils.

AP/Reuters