A Boeing plane full of passengers was forced to U-turn just three hours into an 11-hour flight after its windscreen suddenly cracked. 

Virgin Flight VS41 was on its way to San Francisco on May 23 when the central windscreen on the Boeing Dreamliner 787-9 unexpectedly shattered.

The plane, which had taken off from Heathrow just three hours earlier, was cruising at an altitude of 40,000 feet, leaving cabin staff in shock.

However, they ruled out the possibility of explosive decompression, which would have resulted in anything not secured to the cabin's interior being sucked out into the -50C atmosphere outside, and the flight was diverted.

Pilots were compelled to return to the UK, where airport investigators were baffled to find what appeared to be dents on the four-layer-thick glass.

The airline issued an apology to passengers affected by the disruption, and provided overnight accommodation before they completed their journey the following day. 

This is not the first time Boeing planes have reported cracked windscreens, with another flight forced to return to its destination in 2023.

An Air New Zealand flight to Tokyo had to turn back to Auckland in June after sustaining damage to its windscreen mid-flight. 

Flight ANZ99 made a U-turn after passing Port Vila in Vanuatu, Stuff. co.nz reported, with passengers three-and-a-half hours into a planned 11-hour trip.

An Air New Zealand 787-9 Dreamliner was forced to return to its departure point nearly seven hours after takeoff when one layer of the cockpit's thick glass shattered. Despite only one layer being affected, the decision was made to turn back for safety reasons.

Air New Zealand's top safety officer, David Morgan, explained that this is "standard operating procedure".

He explained: "Windows on aircraft are made up of multiple layers to withstand damage, however, to ensure the safety of our customers and crew it's part of our standard operating procedure to return to one of our ports to allow our maintenance team to undertake repairs."

The incident didn't sit well with some passengers, who vented their frustrations online.