Re: Stand your air
Interstate Commerce Clause, which is in the original document. And since airliners at altitude are a pressure vessel (meaning there are safety issues inherent to them), regulating what's allowed inside them can fall within federal permit. While the MythBusters have shown a bullet hole in an airplane wouldn't cause explosive decompression, it would still constitute a compromise of the airplane's integrity (a la Qantas Flight 30 and the exploding oxygen tank) and force a diversion.
Put it this way. The First Amendment doesn't list any exceptions to the freedom of speech, yet the Supreme Court was able to legally justify one in the Schenck decision (the "fire in a crowded theater" argument: doing so on false pretense compromises others' rights).