Its funny you should ask...I was just contemplating the same thing. A couple of possible reasons.. 1- US has 26 F class seats, I believe, and around 143 Y. I am pretty sure even in coach jetBlue has less pitch than US. JetBlue must be looking at over 200 on an A321. That makes for a lot of extra weight on the plane. 2- Perhaps some of the airports that jetBlue uses have shorter runways and would give flights lower max takeoff weights. 3- They want to go in the history books as having an aircraft custome designed for them. The third one is more of a joke... Jim On Thu, 1 Aug 2002, Addison Schonland wrote: > Noticed that US flies 321s from CLT to SFO and SEA....so why would JBlue > have trouble using it instead of a 320-300? >