we really dont have anything to base when a hangar is gonna pop on other than "its smoking/it stopped smoking"
what i am suggesting is when you right-click on a base and select "(base number) status", when that window pops up that says which hangars are up/down, there would be a timer on the "disabled" items displaying how much time is left before it pops.
for example: "vehicles: disabled- 10:37"
also, would it be possible to display the status of the town in that window?