Hyper interesting route announcement from US Airways today. Come September, the airline is increasing its flights from Charlotte to New York’s John F. Kennedy International Airport (JFK) from three a day to five a day. Charlotte – New York City is an extremely competitive market, with US Airways, American, Delta, United, and JetBlue all flying to the CLT from one or more of the three big, slot constrained, New York City area airports.

JFK has traditionally been the least important of the three airports domestically, especially on routes under 1,500 miles. (Flights from LaGuardia are limited to 1,500 miles or less plus Denver except on Saturdays.) That was until JetBlue made JFK cool domestically with New Yorkers. JetBlue came to Charlotte in July 2006 and has done OK at best here — they started with 400 seats a day and are now at 300. JetBlue’s average fares were the lowest of anyone on CLT-NYC at $137.10 each way in 3Q11 — the average one-way fare was $180.97.

By adding two more flights to JFK, US Airways is really upping the pressure on JetBlue. That will give US Airways 681 seats a day come September, more than twice what JetBlue has. The intent here is pretty clear — to see exactly how important Charlotte is to JetBlue. And US Airways is thinking the answer is “not very” and that JetBlue will leave the Queen City.

Bonus observation: JetBlue also flies Charlotte to Boston twice a day. It’s yields are even lower on that route — only $123.58. Also not exactly a smashing success for the guys with blue-themed planes.