Third Runway at Heathrow- Frequently Asked Questions

1.  How many runways does Heathrow have at present?

It has two runways.

2.  How many flights use the airport?

Over the last few years it has hovered around 476,000 a year. There is currently a cap of 480,000 on the number of flights that can use the airport in any one year.

3.  How many people are overflown?

According to the European Commission, over 720,000 people are impacted by flights using Heathrow.

4.  How does this compare with other airports?

Heathrow Flight PathHeathrow is in a league of its own. 28% of the people across Europe affected by aircraft noise live under the Heathrow flight paths.

Heathrow Flight Path

5. How many flights will there be if a third runway is built?

Well over 700,000

6. Why are we debating a third runway at Heathrow?

The previous Government set up the Airports Commission, Chaired by Sir Howard Davies to examine airport capacity issues and make a recommendation in summer 2015. In its interim report, the Commission narrowed the choice to a second runway at Gatwick, a new runway at Heathrow or an extended runway at Heathrow. The Government will make the final decision and is not obliged to accept the Commission’s recommendation.

7. Why isn’t ‘Boris Island’/Thames Estuary or Stansted being looked at?

The Airports Commission has ruled these options out (although any Government could bring them into play again).

8.  What’s the case for a new runway in the South East?

The Airports Commission says it is likely the current runways in the South East will be full by 2030 and that there will be a need for a new runway. The Commission has concluded there is not a commercial case for a new runway outside the South East. 

9. What are the main arguments against Heathrow expansion?

Air Quality

Areas around Heathrow are already over the EU limits on air pollution. The Airports Commission says that, even with cleaner planes, Heathrow would find it “challenging” to meet the limits if a third runway is built. That seems to be a massive understatement. The Commission’s own analysis found that, by 2030, with a third runway, Heathrow’s Bath Road would have the worst NO2 concentrations of any location in Greater London. A lot of the air pollution in the Heathrow area comes not from the planes but from the car traffic.Even Heathrow has admitted that drastic measures – such as a congestion charging scheme or a banning of diesel vehicles on the surrounding motorways – might be required if the legal limits are to be met. Yet the Airports Commission have not modelled such measures – and so have no way of showing if they’ll be effective. The Supreme Court has also ordered the UK Government to prepare and consult on new air quality plans for submission to the European Commission no later than December 31 2015. This is due to the huge air pollution problems in the UK which means that legally, Heathrow may not be able to expand due to the increase in air pollution that more cars and planes would bring to London.

Transport Congestion

Transport for London have concluded that Heathrow have underestimated the cost of dealing with excess passengers using transport links to an expanded Heathrow by a staggering £15 billion. This raises questions about who would pay for the additional road and rail capacity. Using such a high level of public funds to subsidise a privately owned company will be problematic given all the other demands on Government


Heathrow Airport, by a colossal margin, is the largest noise polluter in Europe.  It currently affects over 720,000 people from noise at levels that cause significant annoyance.

Up to 1,000,000 people could be affected if Heathrow is expanded.

WWorld Health Organisation (WHO) research has demonstrated the harmful effects of excessive noise, particularly on the vulnerable - children, the elderly, those with underlying cardiovascular and mental health conditions. The WHO’s key guidance documents links noise pollution above 55 decibels Lden with, among other effects, aggressive behaviours; stress hormones, high blood pressure levels, reducing helping behaviours and hindering child development.

The Regions

Looking at theAirports Commission’s passenger forecasts, it appears that there would be no overall increase in the number of UK passengers, flights or destinations if Heathrow expands. Instead, the expansion would take business from other UK airports and in particular the regional airports. In short, the effect of Heathrow expansion would be to centralize existing activity, and give Heathrow near-monopoly advantage.

This raises serious doubts about there being any benefit to the UK economy brought about by Heathrow’s expansion - not only because of the lack of any growth but also because of the significant negative impact on the regions.

10. Do we not need Heathrow expansion to stay connected?

Heathrow is one of Europe’s main ‘hub’ airports.  A hub airport is one where many people transfer from one airline to the other without leaving the airport.  Heathrow argues these ‘transfer’ passengers are important because they make it economical for airlines to run more frequent flights to more destinations.  However nearly 30 per cent of passengers to New York, one of Heathrow’s most popular routes, are transfer passengers: no one pretends such routes would disappear without them.

In addition, business flights have been steadily decreasing. In 2000, the percentage of business passengers was 38%, in 2005 it was 35% but by 2010 it was down to 30%.

Also, looking into the future, larger aircrafts will enable Heathrow’s passenger numbers to grow by 30% over the next 20 years removing the need for more flights and runways.

11.  Would homes need to be destroyed?

Yes.  Heathrow Airport’s proposal would require 783 homes to be demolished.

12.  Is there any support locally for a new runway at Heathrow?

Referenda carried out by some of the West London boroughs found around 72% of residents opposed a new runway. Polls commissioned by the pro-Heathrow lobby group Back Heathrow put support for a new runway at just under 50%, but the polls have been widely criticized because of the way they were conducted and are not seen as a reliable barometer of public opinion.

13. Will Heathrow close if it doesn’t get a third runway?

No, the CEO has made it clear that Heathrow will not close if it is not allowed to expand.

14. Are there plans for more than 3 runways at Heathrow?

Yes, Heathrow’s CEO has confirmed that if they get a third runway, Heathrow will campaign to get a 4th.


Additional facts:

Noise and air pollution:

  • A plane lands at Heathrow every 90 seconds
  • • 725,000 people are exposed at 55 decibels Lden, that is, 28% of all people impacted by aircraft noise across Europe
  • A 3rd runway would bring in around 260,000 extra flights a year
  • Air Pollution levels in parts of West London already exceeds the European legal limits
  • A 3rd runway would make Heathrow the biggest single emitter of CO2 – the climate change gas – in the UK

Heathrow today:

  • Heathrow has 990 departure flights each week to the world’s key business centres. That is more than its two closest rivals, Charles de Gaulle (484) and Frankfurt (450), combined.
  • • More passengers fly in and out of London than any other city in the world. Paris, our nearest European competitor, is in 5th place.
  • London has 7 runways – more than all other European cities except Paris which has 8.

Heathrow is poorly used:

  • Heathrow has the terminal capacity to accommodate at least another 20 million passengers a year.
  • Of the top 10 destinations, by number of flights, only one, New York, is long haul. The rest are European or British destinations.
  • On average there are 38 daily flights to Amsterdam, 36 to Frankfurt, 35 to Paris, 35 to Edinburgh, 29 to Manchester.
  • Business trips are less than 20 per cent of the London passenger total

Case against the Hub airport:

  • Growing numbers of experts believe a mega-hub at Heathrow is unnecessary and would inhibit competition and restrict choice.
  • In 2008 David Cameron said; “The economic value of transfer passengers is hotly disputed – after all, they often spend only the price of a cup of coffee in the UK”.
  • In 2009, David Cameron said: “There are now increasing grounds to believe that the economic case is flawed.”
  • David Cameron later promised that if he were to become prime minister there would be no new runway at Heathrow, “no ifs, no buts”.
  • Former Chief Executive of British Airways Bob Ayling told the Sunday Times in 2008 that a third runway would be “a costly mistake……against Britain’s economic interests”
  • Paul Kehoe, chief executive of Birmingham Airport said: “Other countries, such as Germany, have a ‘multi-hub’ airport model – they link their major airports with high-speed rail, and spread the economic activity. They do not stick to the old-fashioned model of just one major airport.”


  • In the past five years, there have been 260 emergency or urgent landings at Heathrow, roughly one per week, as a result of problems such as engine failure, fuel shortages.