A Virgin Atlantic 787 took off this morning from London Heathrow bound for New York in what was billed as the world's first example of a long-haul commercial flight powered entirely by sustainable aviation fuel (SAF).

VS100, aka Flight100, left the UK capital at 1130 GMT and, as of writing, is a little less than half way through its 3,498 mile (5,629km) journey. Fueling both engines of the jet is an 88 percent/12 percent mix of hydroprocessed esters and fatty acids (HEFA) - derived from waste fats like used cooking oil and animal fat - and synthetic aromatic kerosene (SAK) made from dextrose extracted from corn during the production of animal feed.  

Shai Weiss, Virgin Atlantic CEO, reckons the flight proves that pure SAF can be used as a drop-in replacement for fossil-derived aviation fuel. SAF currently accounts for less than a tenth of a percent of global jet fuel consumption, and which flight standards limit to a 50 percent blend, Virgin said. 

"There's simply not enough SAF and it's clear that in order to reach production at scale, we need to see significantly more investment. This will only happen when regulatory certainty and price support mechanisms, backed by Government, are in place," Weiss said. "Flight100 proves that if you make it, we'll fly it."

There aren't any fee-paying passengers on this flight, however: Along with crew, passengers are limited to UK Transport Secretary Mark Harper, Weiss, and Virgin founder Sir Richard Branson.

"I couldn’t be prouder to be onboard Flight100 today alongside the teams at Virgin Atlantic and our partners, which have been working together to set the flight path for the decarbonisation of long-haul aviation," Branson gushed.

It's believed SAFs could reduce emissions from air travel by up to 80 percent. According to Virgin, its SAF blend being flown today is expected to cut emissions by 70 percent compared to traditional jet fuel.

The International Energy Agency estimates that aviation accounts for approximately two percent of global carbon dioxide emissions; combined with other emissions from air travel, the industry as a whole is believed to be responsible for around five percent of carbon emissions.

Hydrogen fuel and battery-powered air travel is also being proposed and tested, but both are still a long way off mainstream, making SAF the most likely near-term path toward net-zero emissions aviation. Additionally, SAF is designed to be a drop-in replacement for fossil fuels, meaning engines don't need to be modified to use it. 

Virgin not the first to an SAF first

Virgin's flight may be the first commercial-sized craft to fly across the Atlantic with both engines using SAF, but it's far from the first SAF milestone as of late. 

Earlier this month, private jet manufacturer Gulfstream flew the world's actual first transatlantic flight fueled entirely by SAF with a Gulfstream G600 aircraft that flew from Savannah, Georgia to Farnborough Airport in the UK. Like today's Virgin flight, both engines on the private jet were fueled with HEFA-derived SAF, minus the addition of SAK, which Virgin said "is needed in 100 percent SAF blends to give the fuel the required aromatics for engine function." 

According to a fact sheet [PDF] shared with The Register by Virgin Atlantic, other recent SAF milestones have included flights operated by Emirates and United that used SAF in a single engine (with fossil fuel in the others), and the US and UK air forces flying 100 percent SAF in military aircraft. 

Swedish regional airline BRA, with aircraft maker ATR and SAF producer Neste, operated a commercial flight on pure SAF in Sweden last year as well. Last week, Emirates flew an Airbus A380 (the largest passenger aircraft in the world) test flight using 100 percent SAF in one of four engines.

In short, the future of aviation is looking potentially a little bit greener ... once you look past all the energy and fuel needed to build, deliver, and maintain the planes and engines in the first place.

"This is further proof that there are no engine technology barriers to the use of 100 percent SAF," said Simon Burr, director of the engineering, technology and safety group at Rolls-Royce PLC, which made the Trent 1000 engines on the Virgin 787 flying across the Atlantic.

"The flight represents a major milestone for the entire aviation industry in its journey towards net zero carbon emissions," Burr said. ®

https://www.theregister.com//2023/11/28/virgin_atlantic_flies_worlds_first/