Cross stitch needles ARE allowed on planes. The TSA advise;
You may place your knitting needles and needlepoint tools in carry-on or checked baggage.
However, there is a wider question here, and that’s;
Can You Cross Stitch On A Plane?
There are two things to think about here, the needles and the scissors. Even though an initial thought is no on both counts, you can take both on, so long as you prepare for it.
We’ve already established that you can take needles onto a plane, however, in practice, things aren’t as simple.
Firstly, they MUST be embroidery needles, as they have rounded ends. In addition, you should be able to show this.
Secondly, they MUST be enclosed in a hard shell.
The best approach here is to buy something like John James Pebble, as it’s clear, so the agents can see, they’re enclosed, and they stay they’re embroidery needles. Limit the amount you bring though, you’re not taking an arsenal.
I will add a caveat there, that sometimes needles can be confiscated. If this is the case, all airports carry sewing kits, which can be picked up for $2-3, and contain a needle (oh, the irony). In some cases, these are even embroidery needles. Just be careful with the point.
This is slightly more complicated. You aren’t allowed to bring sharps, which include almost all scissors. If you can find a pair that are less than 1 inch from the pivot point, and are rounded off on a 1/1 curve, then you can take them, however not only was I not even able to find a pair like this in my research, but they don’t strike me as very useful tools for cross stitch.
There is an alternative though; threadcutters. At the moment you can take two different kinds, the DMC thread cutter pendant(which can be questioned on some airlines), or the Thread Cutterz Ring. I have used both, and I would STRONGLY recommend the ring.
Now you have everything prepared, place both needles and scissors (if you have them) in a clear bag, and treat them like liquids.
On a final note, I would suggest in all cases you should phone the airline before taking them aboard, and NEVER hide them. Also, as a tip, use shorter lengths of thread than usual, you don’t have as much space on a plane.