Flying is an interesting case, per the 5th amendment we have the freedom to travel (liberty). There are too many points to consider for an HN thread, but in general, I would propose flying as a reasonably protected right, but no-fly lists as a violation of that right because of the absolute lack of due process. There is plenty of room for reasonable and effective security measures, as long as they don't intimidate, discriminate, inconvenience, or harass citizens.