In the run up to COP26, there has been a massive media focus on Britain’s domestic airline routes. The Campaign for Better Transport staged a fascinating race last month between the train and plane on a journey from London to Glasgow. For the record, the plane won by just two minutes.

On top of this, controversy was generated around Chancellor of the Exchequer, Rishi Sunak’s budget. Which saw a cut in air passenger duty for domestic flights, leaving environmentalists reeling in the run-up to COP26 and arguing for reductions in train fares instead. However, Heathrow does not need to compete with Britain's railways for passengers, because they both serve different purposes.

Let’s remember what Heathrow actually is – a hub airport. Unlike Gatwick, which caters for point-to-point flights for London and the South East, Heathrow, whilst also doing the same, serves as an airport for people to change planes.

For instance, not every city in the United States has a direct flight to every city in the European Union – that would simply be inefficient. Similarly, not every city in the United Kingdom has a direct flight to New York – there simply wouldn’t be the demand. That’s where Heathrow comes in – by placing many travelling along many varied routes, under one roof.

Therefore, even if the train is quicker from London to Glasgow, a passenger from Glasgow to Heathrow, once their 4.5 hour train journey to Euston is completed, would then need to cross London on the Underground to Paddington and resume their train journey on the Heathrow Express. This is a long journey.

However, flying allows a near seamless interchange from Glasgow to North America, Africa or Asia. Until Heathrow is served by better rail links to the North, flying will be better for connecting journeys.

Granted, HS2 is scheduled to call at the Old Oak Common interchange station in West London in 2029, only 15 minutes away from Heathrow, which will massively speed up rail links between the ariport the North of England and Scotland. However, even with reduced passengers, domestic flights by then could become more smaller, yes, but more cost-effective and sustainable.

At Back Heathrow, we often talk about in our articles and tweets United Airlines’ purchase of a number of 19-seat electric planes from Swedish start-up Heart Aerospace, for short, regional routes out of San Francisco airport from 2026.

Due to their battery power, such small planes become more cost-effective to fly without having to pay for jet-fuel. Meaning low-traffic, regional routes can continue to sustainably operate. Heart Aerospace's planes have an initial range of 250 miles, suitable for London to Manchester flights or Leeds flights, and could cover the remaining people who want to fly into Heathrow to change planes within the next decade.

The train may very well be quicker for Central London to Central Glasgow, but Heathrow’s domestic flights still have an important future for those looking to change at Heathrow for onward international destinations.