The Transportation Security Administration (TSA) will allow you to take a walking cane on an airplane, provided you need it for mobility assistance. They will also accept other mobility aids like walking chairs. However, if you pack your cane in a regular carry-on bag, it must fit within the airlines' carry-on bag size limits. So, it may be better to carry your cane on board in your hand. If you have any doubts, contact the airline you intend to use.