Certain aircraft have presented unusual pressurization scenarios. The supersonic airliner Concorde had a particularly high pressure differential due to flying at unusually high altitude (up to while maintaining a cabin altitude of . This not only increased airframe weight, but also saw the use of smaller cabin windows than most other commercial passenger aircraft, intended to slow the decompression rate if a depressurization event occurred. The Aloha Airlines Flight 243 incident, involving a Boeing 737-200 that suffered catastrophic cabin failure mid-flight, was primarily caused by its continued operation despite having accumulated more than twice the number of flight cycles that the airframe was designed to endure. For increased passenger comfort, several modern airliners, such as the Boeing 787 Dreamliner and the Airbus A350 XWB, feature reduced operating cabin altitudes as well as greater humidity levels; the use of composite airframes has aided the adoption of such comfort-maximising practices.