overscan said:Just to muddy the waters a little:
Although the NAGPAW program was accepted by the Navy's' BuAer as a proprietary concept, Chance Vought learned of North American's effort and also submitted an unsolicited proposal just two months prior to the award date. Ironically, (or coincidentally?) Vought had picked the name Vigilante [sic] for their proposed aircraft.
Source:
Aerofax A-5 Vigilante by Michael Grove and Jay Miller
It gets more confusing. The A3J was on contract in 1955. In 1957, North American submitted a single-engine proposal that they called the Vigilante for the TS 149 requirement (the desired weight and mission were incompatible; NAA opted to bet that BuAer would prefer an airplane that met the desired weight). It looked nothing like the sleek A3J. The artwork on the cover of the proposal included an illustration of the A3J, which obviously hadn't been formally named at the time.