I have a Curve SL and I haven't flown with it yet, so I don't know how helpful I'm going to be. But I've thought about it a lot because it is something I do and have done in the past with my Speed pro.

Just by looking at it and doing some rough measurements. It looks like, if you remove the front wheel (easy),stem/handlebar, seat/ seatpost and maybe the pedals. You should be able to fit it into a standard 30" (Say 30x20x12 or possibley smaller) suitcase with plenty of room to spare (You can pack your clothes with it in bags for padding). If you remove some air from the tires, you might get it into a 29".

To get a narrower fold with the front wheel removed, you rotate the fork so it is 90 degrees from straight and fold the handlepost down the other side of the frame. You could then take your front wheel in your carry on if you want.

I think when I fly, I'm going to remove both wheels and carry them on and put the frame and my clothes etc in a 26" suitcase. The only problem is the rear wheel is a little fiddley to remove so a 30 inch would be much faster to pack and unpack.

I hope this helps a little, I love to hear from people who have done it.