Postcard HU-195549

In this picture you can see the pilots and ground staff of a 'Voisin' aircraft before taking off and flying to the Daugavpils front in 1916 (World War I.). Daugavpils now is a city in Latvia. This particular postcard was actually issued by Air Baltic - the national airlines of Latvia.
Details on Voisin aircrafts at: https://en.wikipedia.org/wiki/Voisin_(aircraft)
Details on Air Balticat: https://en.wikipedia.org/wiki/AirBaltic