May I ask, when we are in cruise and ATC authorized us to descend BELOW the transition altitude, providing also the QNH: When we do the change in the altimeter setting? Right away when we start the descend; or when we are about to cross the transition level? (transition layer) Thank you!
Thats great thanks for the video.. as I know between TA and TL we are not allowed to cruise either we climb or descend. I'm just wondering why? What happens between those two ?