Originally Posted by
agg_karan
Whay would be interesting to see in simulator in cruise if both packs go off & outflow valves fully closed, how long does it take for depressurization.
Depends...
Take the 737 - the acceptable leakage rate is for a 1.5 PSID drop in 100 seconds. Depending on the age of the aircraft and how many leaks it has this can be difficult to meet.
For a 777 - the same acceptable rate for a 1.5 PSID drop must be 240 seconds.