Sept. 1918, via the Ledger Art Service: “Airplane coming down at a difficult angle after a flight over Philadelphia’ Labor Day Parade.” From the looks of it, it seems to be an Army Curtiss JN-4 Jenny trainer, of the same type as the famous stamp.
Signal Corps photo 111-SC-45453 via the National Archives. https://catalog.archives.gov/id/86697115
Enjoy your day. See you tomorrow.