1892-1918 1914-1918 aerialmilitaryoperations aerialoperations airpilots biografi biography fighterpilots flygoperationer freiherrvon förstavärldskriget1914-1918 german germanaerialoperations germany greatbritain historicalnarrativegermanpilotfirstworldwar manfred manfredalbrecht military pictorialworks stridspiloter worldwar worldwar1airoperations