The President of the United States is arguably one of the most targeted men in the world, so it’s not surprising that the security arrangements for the President are largely kept under wraps. According to Politico, whenever POTUS leaves Washington, there is a secret air force of three aircrafts that shadow Air Force One.
The aircrafts look unassuming—just unarmed Gulfstream IV VIP jets from 1985. What you can’t see is that each jet is powered by two Rolls Royce turbofan engines. These plans lack the advanced controls of a modern aircraft, but they are kept in top condition and have special defensive countermeasures to prevent them from being shot down by one of our enemies.
The Gulfstream jets are meant to ferry a traveling President of the United States to safety during a crisis. In the event of a war scare, one of the jets would pick up the acting President and take him to one of a dozen ground command posts throughout the country.
Apparently, that’s not the only purpose for the jets. According to late aviation writer Robert Dorr, the C-20Cs also follow the Secretary of Defense when he leaves the nation’s capital. Dorr believes the aircrafts have either an AN/APR-17 radar warning receiver or have infrared-guided missile systems. Aside from the President, the Secretary of Defense is the only person who can authorize the use of nuclear weapons.
So why use planes from 1985? Apparently, the jets are favored because their antiquated controls would be protected from the electromagnetic pulse (EMP) of nuclear weapons that could interfere with operations.
Source: Popular Mechanics