Air Force One is typically not visible on public flight tracking websites like Flightradar24 due to military and government security restrictions. The aircraft often uses advanced communication systems and operates within restricted military airspace, making it invisible or blocked on civilian flight radar. Sometimes, with the right tools and by searching for its specific aircraft registration (rather than the call sign), it is possible to locate and track Air Force One or its backup aircraft, but this is a rare occurrence and not normally accessible to the general public.

In summary:

• Air Force One is usually not shown on flight radar to the public.
• When trackable, it is often identified by registration numbers instead of the call sign.
• Advanced military communication and restricted airspace contribute to its invisibility on common tracking sites.