besides their civil market, the wrights were able to sell aircraft to the aeronautical division, u.s. signal corps (s.c. 3, 4, and 5) and to the united states navy as hydroplanes (ah-4, -5-, and -6), in which services they were used as trainers. furthermore, the wrights were able to sell licenses to produce the aircraft domestically (to the burgess company and curtis, which designated it model f), as well as in germany. the deal with burgess was the first license-production of aircraft undertaken in the united states and most of the approximately one hundred model bs produced were actually built by burgess. a modified model b, redesignated model ex (for exhibition) achieved fame as the "vin fiz flyer", the first aircraft to cross the united states. burgess also planned a refined version as the model g, but this was never built.