The Republic's air travel safety regulator and the Government are planning for possible post-Brexit flight chaos, TDs and senators heard on Wednesday.

Michael McGrail, chairman designate of safety watchdog the Irish Aviation Authority (IAA), confirmed that the UK would fall out of European Union air travel treaties if the country leaves the bloc without a deal next March. This could potentially ground flights as it would bar air travel between the UK and the EU, including the Republic.

Mr McGrail told TDs and senators on Wednesday that the Department of Transport, Tourism and Sport was working on solutions to the likely problems that Brexit could cause.

"We are working with them to see how those scenarios would work," Mr McGrail told the Oireachtas Committee on Transport, Tourism and Sport. He explained that Brexit's potential consequences fell more under the department's control than that of the IAA.

"There would be a danger that flights to the UK could halt, that would be the fallout position," Mr McGrail said. "I think that there is a lot to be done between now and then and I do not think that it's in anybody's interest that that would happen."

Board vacancies

Mr McGrail confirmed that the Minister for Transport, Tourism and Sport, Shane Ross, had yet to fill four vacancies on the authority's board, which has five members against a full complement of nine.

The sudden death of former CityJet chief executive and retired Air Corps pilot Geoffrey O'Byrne-White in June deprived the board of a sixth member.

Its new chairman said the department had assured him that the vacancies would be filled.

"There is a process ongoing with the Public Appointments Service," he explained. "There is a call out at the moment for applications for the board."

Mr McGrail also said it was critical that Dublin Airport's new runway was built as planned over the next two to three years.

"Dublin Airport reached capacity levels this summer," he said. "There is an urgent need for the new runway to be built in order to allow for traffic levels to grow with passenger demand."

The Government plans splitting the IAA. Air traffic control and navigation will move to a new body, while the existing Commission for Aviation Regulation, now a consumer protection body, will take charge of the safety division.