My son chose to research being a pilot for his Kindergarten career day project.  He is about average height for his age and is slim.  The small fit him fine, and would have been fine if he were bulkier too. We did not use the pants since we had black pants that were regular pants (the costume pants were okay, but were thin pants you would only wear with a costume.)

I found a different pilot costume on amazon that was cheaper with some nice props that I liked better, but my son preferred this one and we went with it as we figured this one wouldn't make him as hot since the other one was a long-sleeve jacket instead of a short sleeved shirt.

The shirt looks good and it closes in the front with velcro - the buttons are just for show.  The tie is really short, but not a big issue.  The hat is adjustable and has a plastic ring around the top to keep it's shape, which is nice.  However, the wings on the hat were off-center.  The hat brim was a bit warped - looked like it maybe it was crushed somewhere in the packaging/shipping process.

Overall it out fine for career day and we now have it as a dress-up costume for fun.

Also, unlike some reviewers, we got the uniform pictured that says "Pilot" (not French version "Pilote.")