d'Aische enlisted in the French army in 1914 and fought as an infantryman, seeing action on the Marne, the Argonne and at Vauquois. He was wounded in action in April 1915. After his recovery, he enlisted in the French "Aéronautique Militaire" in July 1915, first serving as a mechanic at the Avord aviation school and later training to be an observer/gunner at Cazaux. d'Aische, with the rank of Corporal, was assigned to an operational unit, Escadrille F.71, in April 1916 which was based at Commercy near Saint-Mihiel. The unit was assigned to fly reconnaissance duties for the VIII French army corps at Verdun.