One thing about Alicante airport (unless they've changed it since 2007) is that the oversized luggage x-ray machine is a bit on the small size! I've done the trip from Manchester to Alicante 7 or 8 times now and every time my Scicon bike box goes through the machine at Manchester fine. Coming back, it will not go through Alicante's machine.
The trouble is, the security guys there don't seem to speak English and I can't speak Spanish so we have to resort to sign language. They think me pointing at the machine then my bike box and shaking my head means "Don't you dare try x-raying my luggage you bastard!", at least I think that's what they think! At any rate, they wave their truncheons at me, the box and the machine and make it pretty clear that if I don't cooperate, I'll soon be receiving an intimate body cavity search in a backroom somewhere at the airport...
So I hump the box up onto the conveyor belt. I start off with the box upright. It jams. They reverse the conveyor belt and indicate to me to lay the box on its side. It moves forward... and jams! We then try one more time with the box held at a jaunty diagonal angle as it enters the machine... and jams.
After that I have to unpack the carefully-packed box on the floor. Most times, they make me cut all the zipties holding things in place and put the individual bits and pieces through the machine. Then I have to repack everything. It's a right pain.
One time the guard just got me to open the box and used his truncheon to open a few carrier bags full of unwashed cycle clothing. At that point he clearly decided that terrorists don't carry dirty washing and accepted the luggage without further inspection. I had a half-full 2 kg container of carbo-powder which could have contained explosives, but he just waved it through. There's security for you!
Most bike bags and smaller boxes do just fit but Scicons are very big and don't. There's only an inch or so in it.