What is considered proper attire for traveling by airplane?

Well you should probably be comfortable more than anything, how many of those people will you ever see again? I doubt any of them. Another thing is if you look too dressed up you may look like a target to be robbed, if you want to look like big bucks, you might lose a few as well! Now in December I will be flying to Sweden for a month to see my boyfriend, I miss him a lot so I want to wear a nice looking outfit and make-up, and I will also meet his parents for the first time. I want to look dressy but not, I will wear my skinny jeans and a long sleeve shirt, with my Spanish leather boots haha, I will still be comfortable though, I would not go on an eight hour plane ride in heels and stockings, let alone walk around in my daily life like that haha. My attire will just be a regular one, though with a little more thought than usual.

well for me i would surely dress up formal or maybe in a casual thing!

When you are cooped up with minimal room to move on a plane then I go for the most slackest, comfortable clothing I can wear, because I know that I will fidget, won't be able to get comfortable and if things are clinging then I will fidget even more! I am tall as well so not being able to stretch my legs it's like nooooo get me off this cramped confined piece of metal! I think being comfortable is the name of the game rather than dressing to impressing the captain or security guards, and besides the less you wear the less you have to take off if you are taken aside if you get my drift ;0)

yes, I believe one should dress comfortably when traveling. Specially for long flights. i think when your friends say "dress up", it should just be something "presentable".

Dressing for flight is actually simple -- be as comfortable as possible. One can be constricted aboard an airplane as the pressure changes cause our bodies to react. Most people I know who travel a lot have a couple of sets of sweats that are quite dressed-up, so they can look OK while being as comfortable as possible.

There's no way I would dress up to board a plane. I wouls probably wear a sweat shirt and jeans, socks and shoes or sneakers. For one thing, it is usually cold on the plane, and I refuse to pay for a blanket. Comfort is more important to me than glamour when flying on a plane. Even movie stars dress down when they are on a plane.

I'm not sure if the airlines enforce a dress code for international flights, but I do recall an instance when I boarded the plane wearing a shirt, shorts and sandals. It was just a domestic flight, and we were flying home from Boracay island since we spent our honeymoon there. That was four years ago, and the airline staff didn't seem to mind my outfit, probably considering that we just came from the beach.