August 1914 commenced their first reconnaissance flights in the World War I. Tomić took off from the airfield at Jevremovac on 27 August. Above Mišar he encountered an enemy plane Parabellum which opened fire on Tomić, who did not expect this but he avoided it with an appropriate and fast maneuver, so the plane did not sustain any hits. It was probably the first exchange of fire between aircraft in history. Serbian pilots who were actually skilled and experienced from the Balkan Wars had succeeded to give the valuable information about the number, the movements, and the position of the enemy troops. They contributed to early Serbian victories in 1914 at Cer Mountain, Kolubara and Drina river. At the beginning of 1915, armed with machine guns and bombs, Serbian pilots succeeded to fight back the enemy by attacking their aircraft flying over the Serbian sovereign territory or by bombing the important targets in the background positions. Because of air superiority of the Austro-Hungarian Aviation Troops over the Serbian Front, in March 1915 the French squadron (Escadrille MF 99 S) arrived under command of Captain Roger Vitrat to aid the Serbian Aeroplane Wing. The French squadron held the frontline from Smederevo to Loznica, and the Serbian wing from Smederevo to Golubac. After the conquest of Serbia by the Central Powers in the autumn of 1915 and the great retreat of the Serbian army to the Greek island of Corfu, the Salonica front was formed. During the invasion on Serbia in October 1915, Manfred von Richthofen ("Red Baron") was commenced its first combat flight as a pilot. Also, in the autumn of 1915, the first medical transport of the wounded and sick in world aviation history was conducted in Serbia. One of the ill soldiers in that first medical transport was Milan Stefanik, a Czechoslovakian pilot-volunteer. In June 1916 the reconstituted Serbian army sailed from Corfu and joined the French and British at Thessaloniki. At the Salonica front line, with the support of the Allied forces, the Serbian Aeroplane Wing was reorganized. From mid-1916 to 1918 at the Serbian part of the new established frontline, five squadrons (N521, N522, N523, N524 and N525) were operated and were staffed mostly of French and Serbian personnel. These air force units were officially known as the Serbian Army Air Service and were attached to the Supreme Command of Royal Serbian Army which was a part