The designation changes, which will come into effect in April and which are expected to last for the next half century, are required for the airport to remain safety compliant and licensed by the Irish Aviation Authority (IAA).
The runway designator is made up of a two-digit number displayed at each end of the runway showing its magnetic heading nearest the full 10 degrees.
Runway designators are vital pieces of information for pilots being cleared for take-off, landing and taxiing.
The main runway at Cork Airport has, since 1961, been designated runway 17/35 — depending on which direction an aircraft approaches or departs.
But the drifting of Earth’s magnetic poles over the last half century has seen a shifting of the runway’s magnetic headings. They now stand at 164°M and 344°M, respectively.
It has resulted in confirmation from the airport yesterday that the main runway will be re-designated as runway 16/34 from April.
Ciaran Carton, general manager of operations at Cork Airport, said a change in runway designation is an unusual move which only occurs approximately once in every 50 years.
“There will also be an alteration of software systems, new airfield mapping and a change in communications with private and commercial pilots,” he said.
“Additionally, we will be replacing the taxiway signage and painting new designation numbers on runway thresholds.
“It should be noted that the change in runway designator numbers will have no effect on aircraft movements.”
A spokesman for the IAA said the rate of change of the magnetic variation is not linear or constant, but, for Ireland, is of the order of magnitude of one degree every five years.
“Assuming this remains constant, every runway will need to change its designation every 50 years,” he said. “There are no other changes planned at present for other Irish airports, but the magnetic variation is continuously monitored.”