ZAX wont leave the fleet until the E170 enters service, the RJ fleet cant operate with no spare, it's not relaible enough. The fleet needs to remain at 10 hulls, 9 of which operational. In the current climate the only routes that need high capacity are morning and evening GLA and EDI flights as mentioned by BA Laddy. I guess this will change in the coming year or two when the economy starts to pick up. It will be interesting to see if new routes do start next summer, all depends on economy and competition I guess. Some EDI flights are on sale on E170 in Oct.