Titan Airways flight ZT305, an Airbus A321-253NX, departed London-Stansted Airport (STN) on the first stage of an around the world flight. In the climb at approximately 10,000ft, the crew noticed excessive cabin noise and the aircraft executed a turn back to London Stansted. It was discovered that 3 windows were missing and loose, and damage to LH stabiliser. The aircraft in question had been operated on behalf of the U.K. Government in VIP configuration for 18 months. It was flown to Southend Airport on September 23, 2023 to be returned for Titan Airways service. On October 2, it was ferried to London-Stansted Airport. The day before the occurrence flight the aircraft had been used for filming on the ground, during which external lights had been shone through the cabin windows to give the illusion of a sunrise. The lights were first shone on the right side of the aircraft for approximately five and a half hours, with the light focused on the cabin windows just aft of the overwing exits. The lights were then moved to the left side of the aircraft where they illuminated a similar area on the left side for approximately four hours. Photographs taken during filming showed six sets of flood lights on both sides of the aircraft. The lights were between approximately 6 and 9 m from the window areas where damage was apparent. The windows appear to have sustained thermal damage and distortion because of elevated temperatures while illuminated for approximately four to five and a half hours during filming activity the day before the flight. It is likely that the flood lights were positioned closer than 10 m. Whereas in this case the damage became apparent at around FL100 and the flight was concluded uneventfully, a different level of damage by the same means might have resulted in more serious consequences, especially if window integrity was lost at higher differential pressure. Conclusion Several cabin window components were lost during the flight. High-intensity lights that were used during a filming event emitted sufficient IR radiation to heat the acrylic windows to a temperature sufficient to soften them leading to distortion and shrinkage. The distorted windows fell out because of vibration or the pressure differential across them as the aircraft climbed after takeoff. The aircraft returned to the departure airport for an uneventful landing.