The Irish Aviation Authority has said that the number of commercial terminal flights at Shannon Airport is a cause for concern.
Latest statistics from the IAA show the number of flights to Shannon was down almost 24% last month, compared to January 2010.
The number of commercial flights at Cork Airport were also down, minus 6.9%.
Dublin Airport recorded an increase, but only of 0.7%.
Air traffic through Irish airspace overall increased by just over 5% in January 2011 with 1,275 flights passing through Irish-controlled airspace every day last month.