US Airways has made no secret of the fact that it really, really, would like to serve São Paulo. Unfortunately, they haven’t been able to do so yet. The carrier received frequencies for Brazil service, but couldn’t use them due to capacity constraints at the airport there. So US Airways started up Charlotte to Rio instead.
But the airline certainly hasn’t given up on its quest to serve Brazil’s largest city. The slot swap with Delta was supposed to give US Airways access there, but the two airlines are currently challenging the FAA’s decision on that deal in court. (The two airlines were unhappy with the amount of slots they’d have to give up. They offered a compromise, but the FAA did not approve.)
So US Airways decided to get even more creative. If a deal with United gets approved by the DOT, it will be able to fly daily nonstop flights from Charlotte to São Paulo as early as January with 767-200s. How’d they do that?
United has 21 frequencies for Brazil flights. It uses 14 of those for São Paulo service from Dulles and O’Hare. The remaining seven are currently being used for seasonal flying from Dulles to Rio. So those seven would be temporarily (for a few years) given to US Airways. The two carriers are currently asking to have temporary reallocation last indefinitely until the they notify the DOT that the frequencies are going back to United, who says they’ll use them to expand Brazil service.
Meanwhile, United is planning to place its code on the new flight.
But this is some creative thinking from US Airways. If approved they can get access to a market they’ve been excited about for a couple of years now, and plus it can link their network to TAM’s.

So would UA stop flying to Rio? Or drop Chicago-Sao Paolo service?