I don't think you can go overdressed to something like this. I'd imagine everybody will be going looking their best. At every stage you're going to be being watched, interviewed and assessed after all.
Your applying to do a job where ultimately you will be expected to be the CEO of an airliner and exude professionalism to the passengers. Wear a suit!
Think about the two possibilities: even if everyone else is shirtsleeves and casual, you're not going to be frowned upon by the assessors if you're smarter- you've made a real effort. If you turn up casual and everybody else is shiny, creased and spiffing
it's going to be a whooooole lot more awkward I'd imagine!
My two pence. I think this is applicable to all jobs/assessments but especially this one.
All the best, I'm getting my PPL after graduation then hoping to apple to schemes like this myself.
Mav
"apple to schemes like this" is a turn of phrase where I come from, meaning "apply to schemes like this"...just in case anyone thought I'd made a spelling mistake...honest.
Mav