David Putnam was commissioned into the USAS on 10 June 1918, evidently he still flew with SPA 38 after his commissioning, scoring several victories with two confirmations.
Putnam is listed as entering service with the 139th pursuit squadron of the USAS on 30 June 1918. I suspect he may have actually come to the squadron a few days earlier but I am not certain. He died while fighting several Fokker D7s. Apparently he was on his own in this dogfight. The German ace
Georg von Hantelmann from Jasta 15 is credited with shooting him down. Hope this helps.
regards,
MDD