The lose-lose decision
There is a formidable line-up of organisations in favour of adding a third runway at London Heathrow: the government, the Confederation of British Industry, the UK air transport industry and the unions. Then add all those foreign airlines that would fly there but for lack of runway capacity.
The government argues UK plc will be damaged unless Heathrow raises its capacity. British Airways argues it can't expand except by upsizing its fleet to Airbus A380s.
Given that the White Paper on aviation infrastructure calculates the UK's south-east needs two more runways by about 2020, it is undeniable that creating one big, three-runway hub is more efficient from the air travellers' and the airlines' points of view than having three two-runway airports in the area by adding one runway each at Stansted (already planned) and Gatwick. In fact that option would be so much less efficient that Stansted would almost certainly get a third runway, and Gatwick a second, much earlier than would otherwise be the case. The three-runway Heathrow hub would shift more people per unit of real-estate, and it would give travellers more destination and airline choices at one site.
Meanwhile, global big business has traditionally liked using Heathrow, but is falling out of love with it rapidly because the airport is so close to capacity that delay or flight cancellation is far more likely than at competing hubs like Paris, Amsterdam and Frankfurt. That is what worries the government. Aviation is a huge employer, and easy world connections are a wealth-generator for cities and nations.
But air movements growth at Heathrow affects far more people than at Stansted or Gatwick, given that they are (relatively) rurally located. Airlines argue that they will be operating quieter, cleaner aeroplanes by 2020, but the many thousands of households under Heathrow approaches could watch 702,000 aircraft fly overhead compared with the 480,000 they see now. Decisions like this are what politicians are paid for.
BA can't grow at Heathrow except by upsizing to A380s
Source: Flight International