One of the runways at the Defences Forces’ aerodrome has been shut after it was vandalised overnight.
A 50ft section of a landing strip at Baldonnel was damaged and left with a number of fist size "pock marks".
A Defences Forces spokesman said the vandalism was noticed on runway 2911 during morning inspection.
A Casa aircraft had been due to take off and join the search for two missing fishermen off north Dublin but was diverted to the second runway.
“Baldonnel Aerodrome remains fully operational, with all fixed wing flights now using runway 2305,” a spokesman said.
Gardaí and Military Police are investigating and a full review of security at the aerodrome has been launched.
One line of inquiry is that vandals scaled the perimeter fence and damaged the part of the runway furthest away from Air Corps buildings and hangars.
Engineers are to inspect the runway to assess if it is safe for planes to land, and to decide on repair work.