Fly and ViaBrasil are charter airlines that now our offering some "cheap" regular services from GRU and GIG to NE of Brazil, cities such as Salvador, Recife, Fortaleza, and so on. There is also a flight from gru to gig operated by FLY, which is very cheap.
ViaBrasil is a NE brazil airline that link those cities to GRU. It only has 1 727-200
FLY has 2 727-200.
For sure they don´t have any intend to spread out in Brazil.