The plans will see the Northern Runway brought into more routine use and the scheme is low impact way of unlocking new capacity by using existing runway infrastructure, create 18,000 jobs and see an additional £1.5bn GVA generated for the local area and region.
But how long will the consultation take and what is involved?
Tim Norwood is the airport's chief planning officer and he explained the process and how important it is local residents get involved.
He said: "Because we are identified as a nationally significant infrastructure project we have to go through a seven stage process. We are in stage 1 - what we are announcing today is the start of our consultation on September 9.
"What we really want is as many people as possible to provide feedback with their views on our proposals.
"It’s really important we engage with the local residents. To make people aware of our proposals but to make people fully understand each of the different aspects we are covering.
"After the end of the 12-week consultation we will look to refine, taking into account the feedback we have received before submitting our planning application to the planning inspectorate next year.
"In 2023, we will go through an examination phase.
"Then we would hope to get a decision from the Secretary of State and Government towards 2024."
"It’s a several year process and each of these stages there is an ability for local residents, community groups and important stakeholders to play a part in commenting on our proposals. It’s a multi-layered process.
"Once we get the decision from the Secretary of State, we start moving into delivery and implementation so we can open the facility by 2029."
The 12-week public consultation - which is industry best practice - starts on September 9 and will end on December 1.
All the material will be uploaded onto Gatwick Airport's website on September 9 where there will be a virtual exhibition.
They will be holding a number of telephone surgeries so people can book a slot and talk to the team and their experts with any particular concerns.
There will also be a mobile project office that will be in and around the community and so they can hand out documents and questionnaires and direct people to the various channels.
Mr Norwood added: "We will also be holding webinars, we will be looking to groups that we traditionally see as hard to reach and talking to the local authorities to make sure we properly communicate our plans as widely as possible.
"And what we really want to do is encourage as many people as possible to to respond with their own feedback. We can then take that into account before finalising our proposals and submitting them to the planning inspectorate.
"Today is the start of process, it’s a very exciting day, it’s a great boost for our area and shows a great level of confidence and a great level of ambition that we will recover from the pandemic but also we see a future growth and future pathway to bring significant economic benefit to our local communities in terms of the jobs but also to enable people to travel whether that be on a leisure holiday, visit family and friends or to progress business overseas.
"These are all really big aspects for the UK economy and we hope this project will help deliver those benefits in a very sustainable way but also with the support of our local communities."