Kammala jumla mai zuwa: A ranar 1 ga Maris, 1918, an tura Tadija Sondermajer zuwa rukunin jirgin saman yaki na Faransa (GC 12) 'Les Cigognes' ('The Storks') rukunin jirgin saman yaki mafi kyau a Faransa, wanda shahararren ɗan Faransa Georges Guynemer ya ba da umarni, kuma bayan mutuwar Guynemer, ta hanyar mafi girma ace <unk> almara Rene Fonck; a matsayin ɗaya daga cikin manyan matukan jirgi 60 masu yaƙi, an zaɓi Tadija don shiga cikin rukunin da ke da alhakin ayyukan yaƙi mafi wuya a gaban Yammacin lokacin yakin duniya na biyu.
Yaƙin Marne. Daga 15 ga Afrilu zuwa 21 ga Mayu, ƙungiyarsa tana da abokin gaba "Flying Circus" wanda ya ƙunshi mayakan Fokker wanda sanannen masanin jirgin saman Jamus Manfred von Richthofen, wanda aka fi sani da Red Baron. A lokacin wani aiki a sama da layin abokan gaba, yayin da yake dawowa sansanin tare da bindiga maras amfani, Sondermajer ya kai hari daga mayakan Jamus uku. Ya ceci kansa ta hanyar yin wasan motsa jiki, wanda ya sa abokan gaba suka kasa harbe shi. A dawowarsa daga yaƙi na biyu a ranar 21 ga Mayu, SPAD XIII ya kama wuta bayan an harbe shi, ta hanyar mu'ujiza ya sami damar sauka a Flanders, Sondermajer ya tsira daga hatsarin jirginsa amma ya ƙone sosai tare da raunin kafa. Bayan jiyya da sakewa, Sondermajer ya shiga Makarantar Jirgin Sama da Injin Injiniya a Paris () inda ya sami digiri a injiniyan jirgin sama a 1921. A shekara ta 1923 ya bar aiki don zama jami'in ajiya.