I've flown with airlines before where there was a cascading delay due to a "plane deficit" at the terminal (not the technical term, that's my own). Not to say it's always uptime, but I imagine there are instances of constant uptime.
They can't just change things up on a dime like that. Even if it's 3 AM and most planes are sitting on the ground they can't just be used for your flight like that because they are all scheduled to take off in the morning rush a few hours later.
There's not much reason to turn them off outside of maintenance. When they're parked, they're connected to grid power.
Airliners are regularly and routinely shut down. "Cold and dark" is a common startup procedure for the first flight of the day.
A parked Aircraft is not kept powered when there are no maintenance or other routine(cleaning/checks/certification/preparation/restocking etc.)
It is very surprising that how a lot of comments here claim the contrary.
Even when parked for next flight, until resupply and cargo routines are declared, it is also not powered.
I've flown with airlines before where there was a cascading delay due to a "plane deficit" at the terminal (not the technical term, that's my own). Not to say it's always uptime, but I imagine there are instances of constant uptime.
They can't just change things up on a dime like that. Even if it's 3 AM and most planes are sitting on the ground they can't just be used for your flight like that because they are all scheduled to take off in the morning rush a few hours later.