I’m wondering with the recruitment of 100 (presumably airbus rated) pilots from Thomas cook whether there might be plans for some airbus’s to join the fleet, at least temporarily.
I would've thought the recruitment for 2019 crews would've been put on hold or at least slowed down given the Max groundings. So any recruitment TUI mention probably covers any 2019 top ups and 2020 expansion. Really can't see A321's in the fleet unless they are leased in from another Airlines. The introduction of a new fleet type takes a hell of a lot of time, work and money to execute, and would unlikely be worth it if it's only a temporary measure until new Boeing aircraft arrive.
It's more than likely TUI Holidays will find capacity elsewhere (EZY/DY/VY) and TUI Airways will try and keep some of the 757's 767's longer to support capacity increases.