Busy book, wipeable pen skills book, colouring book, brand new teddy/toys, lots of snacks
We just had a 5 hr flight and he was mainly self entertained by his favourite toy characters. Snack box is helpful And the screen time we gave him was doing dot to dot or shape finding puzzles, he loved that. And tbh it didn't feel like 5 hrs at all. Headphones to listen to their own music/a story book... we brought this but he was more interested in playing with his toys
We have a busy book that is really useful. It has counting, poppers, zips etc to play with. I've also found reusable stickers good and the water colouring books that dry back to colourless so they can reuse them x