Passenger numbers at Shannon Airport failed to take off in the first six months of this year, despite an increase at all other Irish Airports.
CSO figures show the number of people travelling through the Midwest airport was down by more than 3% between January and June.
18 million people travelled through the main Irish Airports in the first half of the year, an increase of almost 6% on the same period last year.
Just over 738,300 of these travelled through Shannon, but this is a drop of 3.3% on the same period last year, at a time when the other airports added almost a million passengers combined.
Shannon Group has already advised that 2019 has been a challenging year, after the worldwide grounding of the Boeing 737 Max Aircraft led to Norwegian Air and Air Canada pulling their services.
Its estimated that this would result in an almost 60 million euro hit to the Midwest economy.
Between January and June, London Heathrow and London Stanstead were the top routes for passengers travelling through Shannon, while New York, Newark, Boston and Faro also proved popular.