An Airbus A321 bound for the United States was forced to abruptly return to London Stansted Airport after several cabin windows were found to be missing or damaged, posing safety concerns, according to a bulletin issued by the U.K.'s Air Accidents Investigation Branch.

The incident occurred on October 4, when the flight departed from London Stansted Airport with 11 crew members and nine passengers onboard. The destination was the Orlando, Florida, International Airport.

During the flight, passengers reported that the cabin felt colder and noisier than usual. It was only when an air crew member investigated further towards the back of the plane that it was confirmed that something was indeed amiss. The crew member noticed a cabin window on the left side of the plane with a flapping seal and a slipped-down windowpane.

Upon discovering the missing window, the pilot immediately reduced the flight speed and stopped climbing. The engineer and the third pilot then went to inspect the damage. Based on their observations, the crew made the decision to return to London Stansted Airport.

Thankfully, the plane landed safely and maintained normal pressurization throughout the 36-minute flight. Upon inspection, it was found that two windowpanes were missing, one was dislodged, and another protruded from the left side of the plane.

Investigations by the Air Accidents Investigation Branch revealed that the windowpanes had suffered thermal damage. The damage was attributed to intense lighting exposure during a filming event conducted the day before, where Maxibrute 12 lights were used to simulate a sunrise from inside the aircraft. The lights, meant to be shone at a distance of 10 meters, were placed closer, ranging from 6 to 9 meters, during the event.

The bulletin emphasized that the consequences of compromised window integrity at higher differential pressure could have been far more severe. The incident serves as a stark reminder of the critical importance of ensuring the proper maintenance and inspection of aircraft components.

As investigations continue, airlines and aviation authorities will likely review and reinforce protocols to prevent similar incidents from occurring in the future.