Have you ever received messages from relatives like: "Coming soon, meet me!" Where to meet, what time, at which terminal? It is quite possible to independently find out the flight that your unlucky relative will bring.
Call the newcomer or his relatives in the city where he lives and find out the flight number and departure time from them.
If this is not possible, find out which airport the planes arrive at from the city of departure of the traveler. If there is only one airport in your city, just ask the information desk what time the plane will arrive and what flight it is.
But if your relative flies, for example, to Moscow, then the matter becomes much more complicated. There are five state airports in Moscow, and there are also private ones. However, the latter can be ignored - they have a completely different service system. On the other hand, you will have to call other airports for a long time (the lines are usually loaded), finding out the time of arrival of aircraft from the desired city and the flight number. It's good if only one plane arrives a day, but if there are several? And to different airports? In addition, it is important to take into account the weather factor, which can delay the flight or cancel it altogether. In this case, you will have to try to be in time for everything.
In order not to sit on the phone, you can use the Internet. Yandex has a service called "Schedule" city of departure, you can get information where and when your relative arrives. Enter the name of the point of departure and point of arrival, and the system will select all possible options.
And, by the way, today every major airport has its own page on the Internet with an electronic timetable. After spending some time at the computer, you will have complete information about the place of arrival and the flight number of the aircraft.