There was a french military aviation mission to Russia commanded by a capitaine Berger which served for some period before the tsar's abdication in 1917. After the tsar's abdication there were at least two french units in Russia,
Escadrille N581, commanded by a lieutenant Gueydon, and Escadrille Sop582, commanded by a Capitaine Balavioine. These units were subordinate to the Russian 7th army and participated in the Russian offensive on Lvov in the summer of 1917.
This information taken from Durkota, et.al. 'The
Imperial Russian Air Service' pp142-144. hope it helps.
Regards,
MDD