The president of the Irish Airline Pilots' Association is calling on Transport Minister Leo Varadkar to launch an independent investigation into the effectiveness of the Irish Aviation Authority.
It follows last night's Channel 4 'Dispatches' documentary, 'Secrets from the Cockpit', which featured anonymous Ryanair pilots raising concerns over fuel policies.
This morning, Ryanair chief Michael O'Leary played down the documentary, saying its fuel policies are to ensure smoother flights.
The airline said that it will now sue Channel 4 for defamation.
Evan Cullen, president of IALPA, says last night's programme has raised questions about the IAA.
"There was enough in the programme last night that I saw to raise questions about the effectiveness of the Irish Aviation Authority," he said.
"And what is the harm in having such an investigation, an independent investigation?
"And I'll go back to my original point - if they're doing such a great job, no-one should fear an independent investigation into their effectiveness."
The Irish Aviation Authority responded that it is independently audited by both the European Aviation Safety Agency (EASA) and the International Civil Aviation Organisation (ICAO).
"The Irish Aviation Authority oversees the safety standards of all Irish registered airlines in accordance with EU and international regulations," a statement read.
"All carriers, regardless of size or business model must comply with EASA safety standards in Europe.
"Income from safety regulatory services is managed completely on a non-profit basis.
"Ryanair is the IAA’s sixth largest source of income. Fuel emergencies, whilst extremely rare, do occur occasionally."
[comment]The full IAA response to the ‘Dispatches’ documentary can be found here.[/comment]