1915 Serbia Air Force French Military Airmail Cover
Serbia: 1915 (31 July). French military cover exempt from postage to Paris via Marseilles struck by ‘Escadrille M.F.S. * Le Commandant *‘ violet cachet. M.F.S. stands for ‘Maurice Farman Serbie’, the aircraft manufacturer who was either supplying and maintaining aircraft for the Serbian Air Force. Mail could not be carried across hostile central Europe, and had to be carried through Mediterranean. Ex. W. Robertson.