Each month the Scattered Clouds blog takes a look at the wonderful world of tourism through a data and evidence-led lens, all in pursuit of transforming tourism sector data into insight of course!
Heathrow - September 2025
I .recall a survey from a quarter of a century ago that was quizzing the public about their views regarding the expansion of Heathrow Airport. These were in the days of surveys being a pen-and-paper affair as opposed to being completed online, and something had gone awry with the printing meaning that on each and every occasion an apostrophe should appear there was just a blank space, imagine if you will a series of questions with an answer option that read “Don t know”.
Despite the passing of many years and much public, parliamentary and legal debate there is still no third runway at Heathrow.
However, earlier this summer the government invited promoters to submit proposals for a third runway that could be operational by 2035.
Making predictions is a risky business but I’m prepared to forecast that aeroplanes will not be landing or taking off on a third runway at Heathrow ten years from now. By the end of the 2030s? Maybe. But unless there is a revolution in our ability to deliver major infrastructure projects from managing the planning consent process through to construction it is hard to envisage 2035 being a realistic deadline.
There are two proposals that have been made public, and potentially others that have been submitted to the government without any fanfare. The current operators of Heathrow, Heathrow Airport Limited (HAL), have the more ambitious, and definitely the more expensive, proposal, coming in with a price tag of £49 billion taking into account all elements of their plan.
This would see a full-length third runway northwest of the existing airfield, something that will necessitate putting part of the M25 into a tunnel.
It would allow Heathrow to handle over 750,000 flights per annum, up from 480,000 at present, and would see the construction of two new terminals along with extensive modernisation of existing terminals.
The other proposal we know about is from Arora and would see a shorter 2,800 metre runway built, and this scheme would not require expensive jiggery-pokery with the M25. The Arora plan sees a single new terminal opening within three to five years of the runway seeing its first landings. Unsurprisingly this option is much cheaper than the submission from HAL. It is also understood that the Arora proposal would see a third party, not HAL, operate the third runway and new Terminal 6.
In parallel with the Department for Transport being on the cusp pf reviewing these proposals the Civil Aviation Authority has kicked off its periodic review of how Heathrow is regulated. Many believe that the current arrangement is not fit for purpose and has resulted in Heathrow being one of the most expensive airports in the world according to a raft of airlines. In essence, the more HAL says it is spending on investment the higher the charges it is permitted to levy on airlines, thereby potentially incentivising gold-plated rather than value-for-money expansion plans. CAA says it welcomes ideas regarding how the regulatory framework could be improved.
The mechanism for how, and how much, Heathrow can charge airlines for the privilege of using it is an important component in the financial arithmetic that will underpin how enticing a new runway and crucially the new terminal(s) will be to existing and potentially new carriers. A a terminal designed long-haul travellers may be thoroughly inappropriate if the expanded capacity were taken up by a low cost airline whose route network is exclusively short-haul.
A further aspect of expanding Heathrow is whether this will genuinely lead to better connectivity for the UK as a whole, or whether airlines that currently reside at the likes of Gatwick and London City will decide to up-sticks and move to Heathrow, potentially undermining the ability for these “secondary” airports to be financially viable.
We shouldn’t forget that Gatwick has its own plans to grow capacity, and the government has given “in principle” support to the idea of its northern runway being brought into use as a fully operational second runway, with a decision anticipated by the end of October. The greenlight could (in theory at least) see the second runway in full operation within a five-year timeframe.
Meanwhile London City has submitted an application to the CAA seeking permission to accommodate the Airbus A320neo, thereby enabling the airport to reach its passenger cap (set to rise from 6.5 million to 9 million by 2031) with fewer aircraft movements.
Anyone who lives near an airport will relish periods of peace and quiet when planes aren’t permitted to land or take off, but one oddity is that those living close to London City enjoy such periods from lunchtime on Saturday through until lunchtime on Sunday. This feels like an outlier and were London City to be permitted to operate in line with most airports then passenger capacity could be enhanced without the need to build new runways or terminals.
Back to Heathrow, and if (as opposed to when) a third runway becomes operational this will lead to a sharp rise in passenger numbers, some of whom will be in transit at the airport, but many of whom will be starting or ending their air journey. This will generate a need to expand public transport connectivity to/from the new terminal(s) and it’s unclear that either of the proposals about which we are aware detail how Transport for London will secure the additional funding that creating new infrastructure will require.
Despite operating with the same number of runways now as was the case two decades ago Heathrow has seen annual passenger numbers increase from 68 million in 2005 to 84 million today, helped by airlines filling as many seats on each plane as they do, and by the growing number of routes on which wide-bodied aircraft are deployed, for example Middle Eastern carriers sending squadrons of Airbus A380s to Heathrow each day.
If I’m still writing this monthly blog in 2035 (unlikely!) and there is an operational third runway at Heathrow I’ll happily acknowledge my scepticism about completion dates was misplaced, but I’m quietly confident that won’t be necessary.