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,…