The United States Navy bought 51 of the Model C trainers, including the C-1F, and the United States Army bought two landplane versions with side-by-side seating, designated the EA.
Angkatan Laut Amerika Serikat membeli 51 unit pesawat latih Model C, termasuk C-1F, dan Angkatan Darat Amerika Serikat membeli dua unit pesawat darat dengan versi kursi berdampingan.