Originally Posted by
tdracer
Mana, that's tracked by the shutdown rate. There has always been the possibility that two engines on a twin could shutdown at the same time (or more precisely, on the same flight). For ETOPS, the focus has been to eliminate 'common cause' shutdowns (e.g. maintenance errors or fuel contamination), and manage the rate of independent 'random' shutdowns. There are ETOPS regulations that govern the allowable shutdown rate relative to the max ETOPS time make the probability of a dual engine shutdown acceptably small.
You're focused on one shutdown - with a large fleet of aircraft and engines, one shutdown is not that meaningful - it's the overall rates that you should be paying attention two.
All that notwithstanding, it would be very damaging if there were a related dual engine failure on an ETOPS flight. The record of problems not fully resolved would not play well in the current environment.