Union contracts make running an airline more difficult. They also make understanding the airline industry more difficult. Case in point is US Airways contracts with its pilots.

Recall that America West bought US Airways back in 2005. At the time, America West entered into a transitional agreement with the two airlines’ pilot unions. This agreement includes a minimum number of aircraft that the merged carrier is required to operate and limits what routes (former) US Airways and America West aircraft and crews can fly. Despite operating under one certificate — legally as one airline — for two years now, the transitional pilot agreement remains in place. The two pilot groups are essentially at war with each other over seniority issues, and reaching a permanent deal remains elusive.

The airline’s 25 99-seat Embraer E 190s aren’t covered by those fleet size minimums. They represent the only way the airline can shrink and not violate the terms of its labor contracts. And that’s exactly what US Airways is planning to do. It is close to selling 10 of the planes. It’s rumored that the other 15 will follow.

In June, US Airways and its associated commuter carriers operated 573 daily flights from Charlotte. 38 were on E 190s.

Bonus observation: Recall that US Airways also entered into a deal with Delta to swap 125 sets of slots at LGA for 40 odd sets of slots at Washington Reagan. The press release also said that US Airways was going to increase the average size of aircraft operating out Washington Reagan. You can’t do that with what was at LGA, where 120 of th current 125 flights are on 37 or 50-seaters. Best guess is that the airline is also planning on selling their Northeast Shuttle operation (gates, slots) and using the planes elsewhere within their system (like at DCA).