From raw political lobbying through to social media and advertising, every weapon in the communications armoury has been thrown at this in order to influence the decision-makers, the public and a huge range of stakeholders.
Millions have been spent, dozens of agencies hired, and whole forests destroyed in the publication of hundreds of documents, press releases and briefing papers arguing one case or the other.
So what can the rest of the industry learn from one of the biggest PR battles in years?
The Gatwick Obviously campaign aggressively pitched to the public over the heads of the politicians with advertising on trains, the tube and regular wrap-arounds of the Evening Standard.
They even deluged the pubs of Westminster with beer-mats.
As well as championing their case, they never shied away from direct criticism of their opponent.
Heathrow were more cautious, as front-runners usually are.
Their campaign had its consumer elements too, but it always had a stronger reliance on their traditional strengths – discreet influencing of the business community and high level lobbying.
They also had a great strength, skilfully deployed, amongst the nations and regions of the UK which largely backed them due to the airports better regional links.
The campaigns reached their crucible at the party conferences where it was impossible to move for events, advertising and even "airport lounges" promoting the two schemes.
Whilst the ultimate decision-maker, the Transport Secretary, has always been inscrutable in his neutrality, great efforts were put into communicating with those who might have an influence around the final decision.
In a way, the campaigns illustrate the power of PR, but also its limitations.
To understand this, you first need to understand that the whole process had a pre-ordained outcome.
It was set up by the Government in 2012 as a vehicle to allow them to perform an elegant u-turn on their previous opposition to the expansion of Heathrow.
Indeed, in the early days it was perceived as a battle between Heathrow and Boris Johnson’s idea of an island airport in the Thames Estuary.
The power and force of the Gatwick Obviously campaign changed everything.
Once Boris Island was knocked-out early in the process, large numbers of influential commentators and politicians shifted their backing to Gatwick and suddenly what was intended to be a relatively straightforward process became very, very complicated for the Government.
But, ultimately, the decision did go with Heathrow.
Whilst Gatwick arguably won the PR battle, Heathrow always had more supporters at the top echelons of the Treasury and the business community.
The institutional inertia in their favour was just too strong, and critically, the raw financials of their business case were always better.
PR has huge power, as Gatwick proved. But, ultimately, it has limitations too.
Sometimes the numbers trump everything else. And there is a lesson for all us from that.
Chris Rumfitt is founder & chief executive of Field Consulting