The gallery was previously blocked off with a glass security wall which separated passengers collecting bags, and those waiting to meet them, but has now been removed in an attempt to soften the image of out-of-bound areas.
For the past ten years, the public viewing gallery has been closed, following 9/11 and other terrorist attacks in order to increase airport security.
The gallery has ceiling-to-floor glass panelling and allows uninterrupted views across the airport apron and virtually the entire length of the runway. The move is part of a £4 million refurbishment spend at Belfast International, which in recent years has taken a hit, with the loss of Aer Lingus to George Best Belfast City Airport.
"People used to enjoy it, so we thought: 'Let's re-open it, let's use it again and let's put a bit more fun back into aviation,'" said the Airport's managing director, Graham Keddie.
Last year, London’s Heathrow Airport opened a new viewing platform for passengers at Terminal 4. It became the first of its kind at Heathrow ever since the old Terminal 2’s viewing platform was closed along with the terminal itself.
The 270 degree observation deck has a view of the southern runway, and contains fixed iPads on the platform which show live flight radars.
Manchester Airport has dedicated an entire park to allow visitors to get the best view of the runway. The Runway Park is home to raised viewing mounds which give a clear 180-degree view over the airfield, as well as a Concorde hangar, a Monarch DC-10, Trident, and Avro RJX.