In this strange set of circumstances, a flight scheduled from Singapore to Perth, Australia experienced mid-flight sudden loss of altitude and was forced to make an emergency landing in 2008. The landing was not problematic. Rather, the two instances of uncommanded pitch-down maneuvers caused severe panic, psychological distress, and physical injuries. It was determined that the cause of the in-flight incident was a defective Air Data Inertial Reference Unit (ADIRU), which led to the release of an Emergency Airworthiness Directive to address the problem with the ADIRU.