British Airways flew a completely carbon-neutral flight from London to Glasgow last Tuesday, using a combination of sustainable aviation fuel, offsets, and emissions-reducing measures like switching to half-power during taxiing, in a major step in a years-long effort to reduce the carbon footprint of flying.

The carbon-neutral “Perfect Flight” took off from Heathrow Airport at 10:36 a.m. local time on Tuesday and arrived in Glasgow just under an hour later. It was BA’s first passenger flight to be powered entirely by sustainable aviation fuel, which is blended with standard jet fuel at a rate of 35%.

In a statement, the Chairman and Chief Executive Officer of BA, Sean Doyle, said: “This flight offered a practical demonstration of the progress we’re making in our carbon reduction journey. This marks real progress in our efforts to decarbonize and shows our determination to continue innovating, working with Governments and industry and accelerating the adoption of new low carbon solutions to get us closer still to the Perfect Flight of the future.”

The journey was carried out on an Airbus A320neo, which, according to the airline, uses 20% less fuel and has lighter seats, catering carts, and digital flight manuals and in-flight magazines. The aircraft was also pushed back with electric cars, with only one engine used for taxiing both before and after take-off and landing, with weight and wind data used to determine the most efficient route.

According to British Airways, the remaining emissions were offset. It said that the aircraft produced 62% lower CO2 emissions than a similar flight path it took to Edinburgh in 2010.

British Airways has pledged to offset emissions to be carbon-neutral by 2050.