Low-cost carrier Ryanair has issued defamation proceedings against Channel 4, Associated Newspapers and the Mirror Group.
The legal writs follow a recent broadcast by Channel 4 of a programme about the Irish airline.
In a statement, lawyers for the airline say a writ of summons has also been issued against the Belfast Telegraph.
"We have been instructed to vigorously prosecute these libel proceedings with a view to securing total vindication", Johnsons Solicitors add.
Earlier this week Ryanair sacked one of their longest serving pilots, after he appeared on the Channel 4 documentary Monday which raised concerns over fuel policies and safety at the airline.
In a statement on Wednesday, the airline said it has instructed its lawyers to issue legal proceedings against John Goss.
A Ryanair spokesman has previously said "Ryanair's safety has been independently confirmed as being “on a par with the safest airlines in Europe".
Meanwhile, the Irish Airline Pilots Association has sought an independent investigation into the effectiveness of the Irish Aviation Authority (IAA) in the wake of the 'Dispatches - Secrets from the Cockpit' documentary.
However, the IAA says it operates in accordance with the European Aviation Safety Agency and the International Civil Aviation Organisation regulations.
