Having Departure and Arrival digital screens would be a little troublesome to set up. As Will101 said, the absence of flight numbers, as well as departure times, arrival times, gate numbers and terminals for the airports would impede the formation of departure and arrival "screens" for each and every airport in the game. I do support the idea, however, unless players manually had to set up their flight's flight number and departure+arrival times, a lot of the workload would be on the game and the servers, which would certainly slow down the game. Even if there were screens, assuming that the game automatically made a flight number, departure time, and arrival time for all the flights departing and arriving at the airport, Data Collectors would probably have to collect data on the number of terminals, the number of gates at each terminal, as well as the type of flights (domestic/international) that depart and arrive at a terminal. Airlines building terminals would slightly complicate that matter, as that would mean having a whole new terminal added to the airport's departures and arrivals.
I do support this idea and it's very realistic; many people have apps that are designed to see the departure and arrival times for a flight, and departure and arrival times are almost always put up on screens. However, the amount of coding that would have to go into this may be too much...
If such thing as a departure and arrival screen does begin to emerge in airline-empires, however, it should have some format as in:
Gate/Terminal/Flight#/Destination/Departure Time/Remarks and Gate/Terminal/Flight#/Origin/Arrival Time/Remarks
I'm afraid, though, that Remarks won't exactly be used as much, unless delays, cancellations, and possibly accidents are also factored into the game. However, that would probably need a whole other bout of coding.