The situation in TYS, one of my frequent airports, is really sad from the Delta perspective. Things have gone from eight or nine mainline flights a day to ATL down now to four (three on Saturday). And to make matters worse, instead of substituting RJs for the flights, they're flying ASA ATR-72 props. Basically, they're saying (through their actions) that they need more than 50 seats, but they're unwilling to put in a mainline jet (and wouldn't this be an ideal market for a 100 seat mainline jet?). It's very frustrating to see an airline give up on a market that has always been strong for it in the past.