Never known for their production of military aircraft, Spartan did build a few primary trainers for the United States Navy. The NP-1, loosely based on the civilian C-3, contained several unique features, specially engineered to combat abuse from student pilots. Its robust landing gear was obviously constructed with ham-handed cadets in mind. Also, all four wing tips (through military standardization) were interchangeable all-metal bolt-on pieces, from the end of the ailerons outboard! Therefore, if early trainee miscalculations resulted in minor wing-to-ground contact, crumpled tips could quickly and easily be replaced by removing the external hardware and reinstalling a whole new tip section. This easy-repair innovation eliminated most of a damaged trainer’s downtime (no more having to recover the wing.) Yet, only 201 Spartan NP-1’s were produced and, unfortunately, most of those were scrapped after the War.