Originally Posted by
Can I help you
Any aircraft coming out of engineering is cleaned and security checked once it arrives at the terminal.
This is true. In my time at BA, cleaners did come to clean aircraft while they were in maintenance - often when the aircraft was moved just after a flight and it was staying in for a few days. If the aircraft was only in for a short schedule it would be cleaned and checked on return to the terminal.
In short, it would entirely be possibly to do deep cleans during maintenance (when there is no cabin maintenance), but it’s generally the basic clean that goes on. I remember fondly watching the cleaners come on, clean a bit and then stretch out and watch a movie/have a snooze after I disabled the IFE...