ScotAirways have the luxary of a hangar. I think when it happened last year Loganair night stopped its aircraft at Glasgow, had it de-iced there and flew into Dundee to pick up passengers. All this leads to delays. It is all well and good until an aircraft arrives and the needs de-icing due to say, a snow fall. Then your stuck!
They need a back up plan when their one de-icer goes u/s, which it always does.
And now they have NOTAMed that they have no fuel!