The plane was flying across the Atlantic Ocean when the crack was noticed.
An Air Canada Boeing 787 with 254 passengers on board was flying across the Atlantic Ocean when a crack in its windshield was noticed, forcing the plane to turn back.
The plane was flying from London to Toronto but had to make an emergency landing in Dublin "due to a cracked Captain's side window", the airline confirmed to Business Insider.
While the passengers "were put in hotels for the night" before the boarded a different flight for Toronto the next day, the airline said.
According to the aviation-news website Simple Flying, about one hour into the journey on Saturday the crew spotted the crack and reported the incident. Data from the flight-tracking website FlightRadar24 shows the plane's abrupt U-turn and its landing at Dublin airport.
There have been earlier instances where Boeing 787 planes have experienced cracked windshields. In September, an Air Canada flight from Shanghai to Vancouver was diverted to Tokyo after a crack appeared. However, at the time Air Canada said that the landing was precautionary because the windows had two panes of glass.
A Jetstar Boeing 787-8 plane was diverted to Melbourne, Australia, while en route to Indonesia in September.