Dublin Airport is rarely out of the news. With the debate over a new terminal, acrimony in the Dáil, big personalities like Willie Walsh and Michael O'Leary, problems with congestion and security last summer, and the barrage of advertisement from the likes of Aer Lingus and Ryanair, it is hard to ignore it.
Belfast, on the other hand, has long been the quieter sister. For years, the mindset prevailed that if you wanted to go somewhere, you had go to Dublin. Belfast was a destination in itself, not somewhere you went to go somewhere else.
That opinion was so ingrained, even the airport management believed it. And new managing director John Doran believes Belfast's impressive growth over the last few years stems just as much from a change of thinking inside the airport as well as outside.
"If you ask me why there has been such growth here, I would say it was a confidence thing. The airlines are beginning to have enough confidence in the area to make an investment and put down roots.
"And I would have to say that the airport's attitude changed as well. We had perhaps been guilty of looking at our catchment area as just the area immediately surrounding Belfast, but we have extended that now to all of Northern Ireland and the Border counties.
"Within an hour's drive from here, there are 1.6 million people and with an hour and a half you're talking maybe 2.25 million. We and the airlines began to look together to this new catchment area; if you draw a line across the bottom of Donegal around Cavan and into Louth, for most people within it is easier to get to Belfast than Dublin."
The growth of Belfast International is perhaps best measured in the expansion of its scheduled routes. Throughout the 1990s, there was little to distinguish it from the smaller regional airports in Ireland or Britain, with standard destinations like London, Manchester and Glasgow. Now, as EasyJet's base in Ireland and a target for the American Airlines, Belfast International is only beginning.
In 1999, as the cheap flight revolution was really taking hold, annual passengers hit the three-million mark for the first time, a rise of 1.5 million in 15 years. Within four years, the figure was up to 4.5 million and the magic five million figure is set to be breached this year. Last year the airport's controlling company, UK-based TBI plc, was taken over by Abertis, a Spanish company whose primary interest lies in toll roads. The deal, which cost Abertis £550 million (€792 million), gave it control over Belfast International, Cardiff International, Orlando Sandford International in Florida, Stockholm Skavsta and three Bolivian airports.
Doran has been managing director for the past seven months, having moved across from the smaller Belfast City airport, where he spent seven years.
"My remit here is to keep our position as the primary economic gateway in the region," he says. "Until even three years ago, our only destination outside the UK and Ireland was Amsterdam. Now there are 18 international scheduled flights, including three across the Atlantic.
"Our main areas for expansion will be the larger western European countries and the American eastern seaboard."
Doran does not view Dublin as direct competition though, and he isn't losing sleep fretting about how he can lure passengers up the M1. "In terms of growth and new routes, Dublin is not a primary consideration. We're not sitting around here thinking of how we can attract people away from there up to here," he says.
"We offer a complementary service. We feel we can take the offload of traffic that doesn't want to travel through Dublin.
"To attract more passengers from the south we have focused more on the border counties like Cavan, Monaghan and Louth. Last year we took out poster ads and slots in the local newspaper and radio stations. We got very positive feedback and encouragement back from that so it's very likely we'll be doing something similar this summer."
The next step for Belfast International is investment in infrastructure. At the current rate of progress, the current terminal building will have to be replaced, and Belfast is undergoing a master planning process in line with all other airports in the UK, as required by a British government white paper. As well as a new terminal and more gates, the airport is planning a significant retail park adjacent to the site and has already sub-contracted car-parking arrangements in the first step of significantly increasing parking capacity.
"The horizon date for the master plan is 2030 and, at that point, we expect to be dealing with passenger numbers of around 10 million.
"The current terminal will only comfortably handle a million or so more than the five million or so we currently serve, so we will have to make a decision soon as to when we will develop the facilities. In the short term, over the next five to six years, we will be looking at a south pier. There are 29 gates at present and a south pier will offer us around a dozen.
"We are fortunate here in that we aren't restricted for space and the environmental constrictions are relatively low. Definitely some of the benefits of Belfast are the ease with which you can approach the airport, the speed with which you move through the terminal, and the lack of overcrowding. And we're planning ahead now to keep it that way."