The pilots of Malaysia Airlines Flight MH370 were suddenly confronted by a cascading loss of electrical power in which many of the airplane’s vital systems shut down, placing an urgent demand on the crew to understand and deal with the failures.

Before this loss of power occurred the crew had been able to make regular contact with air traffic controllers and the airplane was able automatically to transmit its position.

After it, no word was ever heard again from the pilots. Its two automatic reporting systems, the transponder continually sending the airplane’s position and a separate system reporting the condition of its critical systems at half-hourly intervals both stopped working.

This new revelation of a serious technical problem and its immediate affects is buried in the arcane detail of a lengthy report issued last week by the Australian Transport Bureau who are directing the search for the Boeing 777. It is the first official acknowledgement of what had previously been only speculation – that there was a sudden loss of electrical power capable of disabling vital systems.