Bit of duff gen there, Monde old bean. The Saab is back operating the Dundee route as normal, the Dorniers are all off doing their normal jobs (charters, Norwich, London City etc.)
The fact that sometimes a Dornier is available at Dundee just gives a bit more flexibility should there be any lack of capacity or tech issues on the Saab fleet, which is what happened last week in two or three places, not just in Glasgow.
Back to normal now (until the next time)!