What happened
On March 25, 2012, at 10:44 Taipei local time, a Boeing 747-400, registration B-16411, was performing an enroute climb as EVA Airways Corporation passenger flight BR702. During this phase of flight, the crew encountered an abnormal cabin altitude and a malfunction involving the left outflow valve. Following the encounter, the aircraft returned to Taoyuan International Airport. There were no injuries resulting from this event.