Can’t stress enough the impact of the Delta/US Airways slot swap on US Airways. Simply put, it establishes a new baseline of service for the airline. And there will be many changes as a result, some obvious, some subtle.

• Some basic math: +42 flights at Washington Reagan National (DCA) – 132 flights at New York City’s Laguardia Airport (LGA) = which would seem to leave +90 (or so) of flights worth of capacity that US Airways could add at its other hub like, you know, Charlotte (CLT). Except, well, maybe not. Many of those flights at LGA are on 37-seat turboprops, which date back to the Reagan Administration.

Since those obviously planes aren’t going to DCA (see below), where are they going? The answer may well be “away.” The turboprops are operated by Piedmont Airlines, a wholly-owned subsidiary of US Airways, with announced plans to replace its existing fleet. So the simple solution could just be to get rid of some of the planes overtime. (Or maybe this inspires US Airways to announce a fleet renewal and fleet reduction.) Turboprops made up 54 of US Airways and its regional partner’s 624 flights from CLT in November.

• When US Airways originally announced the deal, it said it would add flights to 15 destinations from Reagan National: Birmingham, Ala.; Cincinnati, Ohio; Des Moines, Iowa; Grand Rapids, Mich.; Islip, N.Y.; Ithaca, N.Y.; Little Rock, Ark.; Madison, Wis.; Montreal, Canada; Miami, Fla.; Myrtle Beach, S.C.; Ottawa, Canada; Pensacola, Fla.; Savannah, Ga.; and Tallahassee, Fla. Is that list still the plan?

Note in particular Des Moines, Grand Rapids and Madison. US Airways does not currently fly to Grand Rapids or Madison and only serves Des Moines from Phoenix. Hard to imagine US Airways just offering a single (DCA) flight to these destinations, so presumably the airline would link them to either Charlotte or Philadelphia. Note that Des Moines and Grand Rapids are the two largest unserved markets from CLT within 1,000 miles (Madison is 8th). So the slot swap really is the best opportunity in the foreseeable future for US Airways to add some Midwest destinations from Charlotte.

• Then there’s this line from US Airways originally press release:

[US Airways Senior Vice President, Marketing and Planning Andrew] Nocella continued, “We also plan to increase the number of seats we fly at DCA by using larger dual-class jets. This will increase capacity in a dense market, where demand continues to be brisk, without the negative effects of additional congestion.”

US Airways will operate 229 peak-day departures at DCA. Following full implementation of the new schedule, the airline anticipates its passenger enplanements at DCA will increase by 30 to 35 percent as a result of the new flights and use of larger aircraft.

The airline as a finite number of dual-class jets (those with first class). What routes from Charlotte and/or Philadelphia are seeing reduced mainline or large regional jet service so DCA can grow?

• Does having one fewer hubs north of Charlotte increase the change over time that US Airways will offer nonstops from CLT to more smaller markets in the northeast? (Islip, Elmira, etc.)

So, yes a lot of moving pieces. Will be very interesting to see how this plays out.