日本航空回应上海至东京航班备降：增压系统出现异常指示，降低到安全飞行高度，具体原因调查中。（澎湃）

Core Viewpoint - Japan Airlines responded to an incident involving a flight from Shanghai to Tokyo, indicating that an abnormal indication in the pressurization system led to a descent to a safe flying altitude, with investigations ongoing into the specific cause [1] Group 1 - The flight was forced to descend due to an issue with the pressurization system [1] - Japan Airlines is currently investigating the exact cause of the abnormal indication [1]