FR24 is showing that a STN flight next week will be operated by an A321. Are they possibly going to be using Titan charters from STN again? Wouldn't be too surprising given 9 x 738 have now gone to Sunwing (surely there will be no more). TUI don't have many flights from STN in winter (only 2 per week right now but it does increase going into ski season and perhaps they don't have the equipment to cover this) and with Titan being based there I suppose it makes sense.