From the Commission For Aviation Regulation determination on the charge that the IAA can levy for ATC services.
The Commission has included a trigger in the formulae that will increase the
price cap should passenger numbers at Dublin airport exceed 23.5 million in a
12-month period. The increase is calculated to be sufficient to allow the IAA to
build a new control tower or adopt an alternative technological solution such
that it can continue to provide aviation terminal services at Dublin airport
should the DAA build a second runway there.
This is the trigger to start a new TWR.
I would assume the DAA trigger for a new RWY is the same.
The Commission For Aviation Regulation regularly reviews the Passenger charges that the DAA can levy.
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