How long until landing?
at-ter-RAG-gio — stress on third syllable, double 'g' creates a harder sound.
During the latter part of the flight when you want to know how much time is left.
'Quanto manca a' (how long until) + noun is a very useful construction for asking about time remaining. 'Manca' comes from 'mancare' (to be lacking/missing). 'Atterraggio' is the noun for landing (from 'atterrare'). On the seat-back screen, the time remaining is usually displayed.
Siamo in fase di discesa?
Are we in the descent phase?
You can feel the descent — confirm with crew
Tra poco atterriamo?
Are we landing soon?
Informal and slightly anxious-sounding
Quando dobbiamo mettere il sedile in posizione verticale?
When do we have to put the seat upright?
Required during final approach and landing
The final 30 minutes of a flight involve seat preparation (seats upright, tray tables stowed, window blinds up). Toilets are typically locked during the final approach. Passengers should be in their seats with seatbelts fastened from approximately 20 minutes before landing.