When the Battle of the Aisne began in April 1917, "Escadrille Let 46" was attached to Felix Brocard's Groupe de Combat 12 for the fight. When their commanding officer, Didier Lecour Grandmaison, his replacement, Marcel Bloch led it as it re-equipped again, this time with Caudron R.XI three seated bombers. The unit designation reverted to "Escadrille C46" on 17 February 1918. The squadron operated as part of "Groupe de Combat 15" in the Champagne region until 14 May 1918.