Unsurprisingly, China Eastern Airlines has now grounded its fleet of Boeing 737-800s. This popular and well-used civil aircraft has a good safety reputation. Until more is known, the airline is taking a precautionary approach. 123 passengers and 9 crew members have been lost.
If the video evidence from a security camera is to be taken as reliable, then the dive of the Boeing 737 was uncontrolled and significant structural damage was evident. The on-line pictures show the aircraft at a relatively low altitude. So, it’s not possible to say at what point prior to these images that structural damage occurred. The speed of the dive could have either caused or contributed to the aircraft’s break-up.
Whatever it was that suddenly led to a complete loss from 30,000ft remains mysterious. Looking at the aircraft transponder data, the indications are that the flight was normal up until a point where an unexpected event occurred that was immediate and devastating. Even if the flight crew did have some recognition of failure conditions on-board, it does seem that little time to intervene was available. One assumption in aviation is that crews are provided with training in respect of emergency and abnormal procedures and can act accordingly when failures occur.
A great deal hangs on the recovery and replay of the two accident flight recorders.
The accident flight recorders are separate and installed in the rear section of the aircraft. This is done to increase their chances of survival in most accident and serious incident scenarios. Each requires electrical power. Several means of providing power are available including the aircraft’s batteries. However, if the electrical power wiring to the recorders is severed then they will stop recording. This is true for wiring from their aircraft data sources too.
Let’s hope that there is a complete recoverable record.
John Vincent 