Thomson thankfully have a good balance on how they operate their schedule.
The summer/winter season in the UK and Ireland have a huge capacity difference so alot of operators sub of some work otherwise they would have aircraft laying around for months in the winter.
XL had a good system were they would send several 737's to Sunwing Airlines in Canada for the winter season which is their busy season. And they registered the aircraft in Canada so they could use the sunwing pilots in the summer and a mix of sunwing & XL cabin crew. This reduced costs in the winter but its a complicated system and as we all know it didn't exactly save XL.
Does anyone know the date when G-DIMB leaves the fleet??