The compromised window was discovered by a crew member mid-flight.

A passenger airplane made an emergency landing to Dublin Airport on Monday morning, following the discovery that one of the aircraft's windshields had cracked. Lufthansa flight LH-978 was flying from Frankfurt to Dublin when the crew declared an emergency over the Irish Sea west of Blackpool, England at around 10.45am. The crew of the Airbus A320 jet reported that a crack had appeared in one of the cockpit’s windshields, but it's understood that the damage was confined to just the outer layer of the window. The flight crew requested clearance from Dublin Airport to descend earlier than usual but confirmed there were no other issues with their aircraft. The crew did not require emergency services on arrival. The flight landed safely at 11.23am but was immediately taken out of service so that repairs could be carried out. The airline has confirmed that the return leg of the flight, LH-979, has been cancelled as a result. A spokesperson for Lufthansa released a statement to JOE about the incident. "Lufthansa can confirm that flight LH978 scheduled today, 23 April 2018, from Frankfurt to Dublin with 149 passengers on board landed safely in Dublin at 11:17 a.m. local time," the statement began. "The cockpit windshield was slightly cracked during the flight, however this did not impact the safety of our passengers at any time, thus the aircraft could land normally in Dublin as scheduled. "As a standard procedure, the windshield is currently being replaced and therefore, the return flight LH979 from Dublin to Frankfurt had to be cancelled. Passengers scheduled on this flight are being rebooked on alternative flights. "The safety of our passengers and crew members continues to be our top priority at all times."