One pipe you see there has a rim round the bottom where the others don't but that's ok that will be the end that will go under one of the bottom wings out of sight attached underneath the wing
lol.
When ur very short of money and your local junk yard doesn't always have this size of pipes to give away or for cheap and you need to keep the pipes this length really for the look of it plus that end is going to be hidden under the bottom wing anyway it doesn't really matter.