Where all engines are lost the usual procedure I believe is to drop the RAT ( Ram Air Turbine) which provides the power to re-start the engines. Unfortunately most long range airliners cruise at 39,000 Ft.and the RAT doesn't work at that altitude because the air is so thin so they have to descend to a lower altitude before the RAT kicks in. The reason I know something about this is that a BIL of mine was flying co-pilot from Anchorage to Tokyo when all four engines died due to "Engineer error " in fuel management. The Rat was meant to kick in at 18,000 feet, at 13,000 feet they were getting concerned but eventually they got things started. Air crews do train for this.
Interesting, thanks for the post.
Can you imagine being the pilots in such a situation?
Even with all their training, I bet they hit the johns soon!