Gatwick bosses are beginning detailed work on the option for a new runway at the airport.
But the plans will honour a 1979 legal agreement that no runway can be built at the West Sussex airport before 2019.
The options will be submitted to the Government-appointed aviation commission, led by former Financial Services Authority (FSA) chief Sir Howard Davies, which will make its full report in summer 2015.
Gatwick chief executive Stewart Wingate said a new runway at Gatwick "could be affordable and practical" and was a better option than new runways at Heathrow or Stansted airports.
The work on a new runway at Gatwick, which serves 197 destinations and handles around 34 million passengers a year, will evaluate various runway options and assess key requirements, including environmental, surface access and economic impacts. Relevant environmental issues will include noise and air quality impacts on local communities.
Gatwick's work, and subsequent submission to the Davies Commission, will include a detailed evaluation of how Gatwick's existing single runway capacity can be maximised to contribute to the short-term capacity needs for London and the UK.
Mr Wingate said: "Over the last three years we have transformed the airport, invested around £650 million and have a strong track record for delivering key routes to growth markets. However, we must now look to the future when Gatwick will become full and outline its long-term role in ensuring London has an efficient and resilient airport system that creates the crucial connectivity London and the UK needs."
He said there are "clear practical advantages" of a new runway at Gatwick, adding: "When compared with a third runway at Heathrow, we would have a significantly lower environmental impact whilst adding significantly more capacity. Stansted is half empty today, we already have much better surface transport links and feel our business case will be much stronger."
Mr Wingate continued: "As for the (Thames) Estuary airport concepts (favoured by London Mayor Boris Johnson) there are major questions on affordability, environmental issues and whether they are deliverable."
Brendon Sewill, chairman of the Gatwick Area Conservation Campaign, said: 'We have always been totally opposed to a new runway on environmental grounds, and have had massive support from across Surrey, Sussex and west Kent. We have been supported by all the local MPs and all the county, district and parish councils in a wide area. If necessary, we will resume the battle."