First Russian aero firm was Peterburgskii Tovarishchyestva Aviatsii (St Petersburg aviation company), which among other things built PTA No. 1, based on Farman IV but made in easily disconnected sections to meet army requirement. Retained 50-hp Gnome, but seat in streamlined nacelle. Completed 26 January 1911, flown by V.A. Lebedyev, 'not inferior to Farman'.