Officially, the truth is no, they may not always carry.

The regulations/policy and procedures make no distinction for federal LEOs or state/local LEOs.

One of the more important criteria I mentioned above, namely that the officer's duties require that s/he must have access to the weapon from the time when it would otherwise be checked to when it otherwise be collected after deplaning.

So as with non-federal LEOs if there is no stated need then no, a federal LEO may not fly armed.


However, as mentioned earlier, in practice, much deference is granted to Federal LEOs. Their "need" is interpreted quite broadly for Feds (e.g., to or from prisoner escort, to or from protective detail, surveillance, to or from reporting to another duty station armed and prepared for duty, etc.) or just otherwise ordered to always be armed and ready. They are also generally considered to be on duty all the time.

So in practice, once one has met the training and other requirements, they are pretty much always allowed to fly with access to their weapons.

Being on vacation should be an exception....