Transport Secretary Heidi Alexander gave the green light to Gatwick Airport’s second runway on Sunday, approving the privately-financed project that will add 100,000 flights annually and create 14,000 jobs by moving the airport’s emergency runway 12 metres north for regular use.
But for residents across Putney, the key question is what this decision means for the far more disruptive plans to build a third runway at Heathrow – proposals that would fundamentally alter flight paths and bring aircraft noise to parts of the borough currently enjoying relative peace.
The relationship between Gatwick’s approval and Heathrow’s future has split aviation experts and politicians.
London Mayor Sadiq Khan argues that Gatwick’s expansion undermines the case for Heathrow, telling the London Assembly in January that “if Gatwick was to be given permission for a second runway, that makes it a slam dunk against any possibility of a third runway at Heathrow”.
However, aviation industry experts maintain the airports serve different functions. Royal Aeronautical Society analysis notes that “much of the Airports Commission’s decision to back the third runway at Heathrow was founded on the fact that a third runway there would drive connectivity in a way other options wouldn’t,” emphasising that Gatwick “remains primarily a point-to-point airport” while Heathrow functions as a global hub.
The government appears to back the latter view. Rather than treating airport expansions as competing alternatives, Chancellor Rachel Reeves announced in January that the government supports expanding multiple London airports simultaneously, having already approved growth at London City Airport and Stansted alongside the Gatwick and planned Heathrow projects.
New Flight Path Threats for West Putney and Putney Heath
For Putney residents, a third runway at Heathrow would represent a significant escalation in aircraft disruption, affecting areas of the borough that currently experience little or no aircraft noise.
Under the present system, residents “between Heathrow and about Putney and Fulham benefit” from runway alternation, which provides “a half day’s break from the noise” when aircraft switch runways at 3pm. This system has been in place since the 1960s and provides predictable periods of relief.
A third runway would shatter this arrangement. Flight path projections show that approaches to a southern runway would affect “Putney Heath, Roehampton, Richmond Park” along with “Streatham, Balham, Tooting, Wandsworth Common, Earlsfield, Southfields” – bringing regular aircraft noise to areas like West Putney and Putney Heath that are currently largely spared.
The scale of the change would be dramatic. The 2M group, representing 24 local councils, estimates that while 1 million people currently suffer from Heathrow aircraft noise, expansion could affect 3 million people across London and the South East.
Local MP Andy Slaughter, who represents Hammersmith but borders Putney, warns that “a third runway would bring up to 270,000 additional flights each year, that’s 756 more every day – which is the same number that currently arrive and depart at Gatwick”.
Heathrow Plans Moving Forward Despite Opposition
Despite decades of controversy, Heathrow’s third runway appears to have strong government backing. The government has invited Heathrow to submit detailed proposals by summer 2025, with the airport aiming to secure planning permission before the end of this Parliament.
Any expansion must be delivered “in line with the UK’s legal, climate, and environmental obligations,” with the government promising to review the Airports National Policy Statement “at speed” once proposals are received.
The airport is exploring options to reduce costs from the original £14bn proposal, including building a shorter third runway to avoid expensive infrastructure changes such as diverting the M25 motorway into a tunnel, though this could limit operational flexibility as some aircraft may not be able to use it.
With a projected completion date around 2040, Heathrow claims the expansion would increase annual capacity from 84 million to 150 million passengers, handling up to 756,000 flights annually.
The Bottom Line
For Putney residents, Gatwick’s runway approval appears unlikely to derail Heathrow’s expansion plans. The government’s commitment to multi-airport growth, combined with aviation industry arguments about Heathrow’s unique role as a global hub, suggests the threat to areas like Putney Heath and West Putney remains very real.
The key battle ahead will be ensuring that if expansion proceeds, robust noise mitigation and flight path management systems protect residential communities across the borough. With government decisions on Heathrow expected by the end of this Parliament, residents have limited time to make their voices heard in what may be the final chapter of this decades-long debate.
