 Complete the following phrase:  In 1912, Petrović was one of six Serbian military personnel selected to undergo training at Henri and Maurice Farmans flying school in Étampes, near Paris. Following his completion of the training program, the Fédération Aéronautique Internationale FAI issued Petrović with pilots license 979, making him one of the first 1,000 pilots certified by the organization. Upon completing his training, Petrović returned to Serbia, together with the other newly certified Serbian pilots. During the 