Sorry Bruno, N/SPA37 are my focus and it's their performance in the period early 1917 until the Spring of 1918 that I find unusual - especially when in the Spring of 1918 they begin a run of success that will continue until the end of the war.
I have been pursuing another strand of this pilots career. He is shown in many accounts as serving as an observer in C51 from July 1915-September 1915 but I can find no trace of him in the unit journal for this period and this document...
https://www.archives71.fr/arkotheque...053eca47896a0b
...indicates he left his cavalry unit on 19 September 1915 to go to 2e Groupe d'aviation and thence to Pau.
(it also notes he was promoted to quartermaster-sergeant in 1914).
regards
Keith