Plane and train questions

Can an English Speaking person please tell me how to naturally say the sentences?

>>>What is the average altitude that a commercial airliner flies?

>>>We were late in arriving at the airport.

>>>The plane was losing altitude fast.

>>>The train stops at each of the stops./goes through each of the stops.

>>>The one percent of the time that this does happen, if you don't have your seatbelt on, the consequences can be grave.

>>>Those two stops are further apart than these 2.

>>>Do we get off on/through the left side or the right side?

>>>The subway will be stopping for traffic regulation.

Thank you in advance