Second “Wow!” airline transaction of the week. Still trying to work through exactly what it all means, but US Airways and Delta agreed to a major transaction today centered on swapping slots at Washington Reagan (DCA) and New York LaGuardia (LGA) subject to government approval. A Charlotte – Sao Paolo, Brazil flight is also involved. The highlights:

Delta gets:

125 pairs of slots for regional air service currently used to provide US Airways Express service at LaGuardia plus gates at LaGuardia. US Airways is left with just service to Charlotte, Philadelphia, Pittsburgh, and Wilmington plus the Northeast Shuttle service to Boston and Washington, DC . Shuttle service shifts to the Marine Air Terminal, rest in Terminal D.

US Airways gets:

42 pairs of slots at Washington, D.C.’s Reagan National Airport. These will be used to provide service to 15 new daily destinations, seven that current have service to DCA (Cincinnati, Ohio; Des Moines, Iowa; Grand Rapids, Mich.; Madison, Wis.; Montreal, Canada; Miami, Fla.; and Ottawa, Canada) and eight that don’t (Birmingham, Ala.; Islip, N.Y.; Ithaca, N.Y.; Little Rock, Ark.; Myrtle Beach, S.C.; Pensacola, Fla.; Savannah, Ga.; and Tallahassee, Fla.).

Sao Paolo access:

With today’s transaction, US Airways has acquired the rights to serve Sao Paulo; and anticipates starting service to Sao Paulo in the second half of next year. The airline’s plan to begin daily Charlotte-Rio de Janeiro service this December remains unchanged. US Airways will be working with governmental authorities in both countries to assist it in securing additional authority to permit daily flights between Charlotte and both Rio de Janeiro and Sao Paulo.

And finally, access to Tokyo. The flight is tentatively listed as Phoenix – Tokyo and won’t begin until 2012 at the earliest.

Tentative analysis: This is big. US Airways has been using LGA as a mini-hub for connecting passengers from New England headed to/from points south. This will place more importance on CLT, PHL and DCA in their network.

Unanswered is what happens to the 80-odd daily regional flights that are at now LGA but won’t transfer to DCA. Also note that US Airways doesn’t currently serve Grand Rapids or Madison; will those airports also now get service to CLT (or PHL) as well?

Exactly what the Sao Paolo transaction means is unclear as well. Better said, how this gets US Airways into Sao Paolo is unclear. Does it tie into the additional Brazil frequencies to be awarded next year or is something else envisioned?

Also, will Delta now resume flying CLT-LGA?

Update: Apparently the deal involves swapping US Airways’ seven restricted Brazil frequencies (effectively can’t be used for Sao Paolo) for seven of Delta’s unrestricted Brazil frequencies (which Delta would use for its ATL-Rio flight) and then having US Airways bid for replacement restricted Charlotte -Rio frequencies next year. Remember, Sao Paolo is the biggest market in Brazil.