A few hints / suggestions:
- Pack in your carry-on luggage
- Place in weather radio mode in case you have to turn on and demonstrate to TSA
- Pack the antenna, cables, adapters, etc in a plastic bag / container
- PACK THE MANUAL along with the scanner to help explain if asked
- Use discretely in waiting areas with headphone / earphone
- Don't use on board
No problems flying with one in either a carryon or checked luggage. You'll need to demonstrate that it works to TSA if you carry on, much like any other device (cell phone, laptop, etc). Using it in the air is generally a no-no, most airlines will not allow it. To be honest, on the one flight I took that DID allow me to use it, I didn't pick up anything other than the pilots themselves. The plane was too well shielded to allow for listening to much else.
I kept mine in bag and had no problems, Even had time to listen at the airport but make sure you have frequencies ready before getting to airport if available, Print them up and place in bag with scanner. Spent more time trying to figure out what our airline service was on missed other traffic.