Analyzing the Descending Flight of the Germanwings A320 4U9525

Something (on 2015-03-26, 10:00 still unknown) caused 4U9525 to descent. All the rest is the automatic reaction of a properly functioning Airbus A320 to these initial conditions: The aircraft is disengaging the autopilot automatically at a Mach number of 0.82 as a consequence of High Speed Protection and follows a subsequent descending flight in manual mode (with normal Fly-by-Wire flight control laws) and idle thrust. The pilots probably are neither touching the side sticks nor the thrust levers. At least, it does not need any pilot intervention to explain the cause of the last 9 minutes of the flight and the final tragic effect.

2015年3月26日10:00时刻，某一尚未明确的诱因导致航班4U9525进入下降状态。后续所有过程均为状态正常的空客A320（Airbus A320）针对该初始触发条件产生的自动响应：该飞机因触发高速保护（High Speed Protection）机制，在马赫数（Mach number）0.82时自动断开自动驾驶仪，随后进入手动模式下的下降飞行阶段，此时采用正常电传飞行控制律（Fly-by-Wire flight control laws）且推力处于慢车状态。机组人员大概率既未操作侧杆，也未拨动推力杆。至少就本次航班最后9分钟的飞行过程及最终的灾难性后果而言，无需机组人员介入即可解释其成因。