Some of those business plans on the Carlisle planning portal and the previous applications make interesting reading.
Stobart proposed they needed a 58% load factor on an ATR (didn't specify which one) with a £49 ticket cost (before ancillary costs) to break even.
So, if it's an ATR 72 just shy of 50 people for a flight to Dublin or London? You would have thought that's doable with the right advertising and the cost of rail etc but I guess the lack of uptake by airlines over the years and success Loganair had suggests otherwise.