how old is Thomas? I remember various stages of flying with my Tom. When he was little it was SO EASY...he slept! As he got older it got harder and I would be forcing the dummy in his mouth on take off or landing. Now I have to have dummy, bottle etc all ready to alternate...little monkey! Just be careful they spit their dummies out onto the floor and then they roll under seats and are bloody hard to retrieve. I'd recommend taking a couple, plus toys, books, snacks (if he's on solids) and outting them in a little bag that you can tuck into the pocket in the seat in front. Its really hard to bend down and pull things out from the under the seat...especially with a wrigglebum!
Peek a boo worked well! and Tom like to "read" the safety instructions...its laminated so he couldnt destroy it!
hopefully you will be so busy looking after Thomas that you wont have a chance to worry.