Trump's secret plane switch: How Air Force One protects the president from threats

President Trump's secret plane switch in Turkey is putting Air Force One's security protocols and defensive capabilities in the spotlight.

Why it matters: Air Force One is the call sign for any Air Force aircraft carrying the president, meaning Trump's secret switch didn't change the designation — but it changed the plane protecting him.

Driving the news: A threat from Iran forced Trump to secretly switch planes, using a catering truck to move to a smaller aircraft, per the Washington Post .

Trump flew to Turkey on a plane gifted by Qatar , which was meant to serve as Air Force One.

Officials said he would return on an older presidential plane because of security concerns, per multiple reports , After boarding the older plane, Trump moved to a smaller Air Force C-32A, according to the reports .

All three planes flew to the U.K., where Trump joined the Qatari plane and flew home.

When asked for comment Tuesday, the Air Force pointed Axios to a statement about the Qatari-gifted plane, dubbed the "VC-25B Bridge." The White House did not immediately respond to Axios' request for comment.

How Air Force One handles threats President Trump boards Air Force One at Joint Base Andrews in Maryland.

Photo: Win McNamee/Getty Images Context: Boeing 747-200Bs designated as VC-25A have served as the primary Air Force One aircraft since the '90s and are designed to withstand multiple threats.

EMP protection: The aircraft has shielding to withstand an electromagnetic pulse (often seen from nuclear detonations), per the White House .

Its airframe is reinforced with ballistic-resistant materials.

Command and control: The White House says the plane is fitted with "advanced secure communications equipment" to operate as a mobile command center during any attack on the U.S.

Missile threat defense: Air Force One contains multiple defense systems to help the plane detect any imminent threat.

The Pentagon says the plane comes with "a self-defense system." In-flight refueling: The White House says the VC-25A can refuel while in the air, increasing the aircraft's survival capabilities.