A frequently asked question for knitters is "Can I bring my knitting needles on the plane?" As we embark on the summer season of travel and fun... here is the TSA link and answer
"Knitting needles are permitted in your carry-on baggage or checked baggage.
Items needed to pursue a Needlepoint project are permitted in your carry-on baggage or checked baggage with the exception of circular thread cutters or any cutter with a blade contained inside which cannot go through the checkpoint and must go in your checked baggage"
I know a few seasoned travelers carry a printed out copy of the TSA rule laminated in their knitting bags.
With that said Always check with your individual carrier as some have stricter rules. For example, British Airways prohibits knitting on flights.