The catchment area for carlisle is alot bigger then you think, dont forget the Lake District National Park,tourists from the USA and all over love it.
The west coast towns of whitehaven, workington and not forgetting the city of carlisle are crying out from airlinks, my family live in workington a big town, the closest airports to them is NCL,BLK or GLA all over 2.5 hours drive, I this day and age most people only have an hour or so drive to the airport and I would not miss the drive from essex to cumbria 5.5 hrs.