Air Force One All-Access Pass: Secrets of the Iconic Presidential Aircraft

— -- Air Force One is one of the most iconic symbols of the American presidency. But as a flying monument tasked with transporting the commander-in-chief, it is also one of the most vulnerable targets.

“Every movie, they go after Air Force One,” co-pilot Lt. Col. Tom O'Boyle joked with ABC News’ Chief White House Correspondent Jonathan Karl during an interview in the rarely-seen cockpit of Air Force One. “Whether it's a TV show or it's 'Iron Man,' they're always trying to blow up Air Force One, which is a little concern to me because this is my day-to-day job, but in the real world he is very well protected."

The secrets of the recognizable blue-and-white Boeing 747 plane -- heavily modified by the military to be strong enough to function as an airborne bunker for the nation’s commander-in-chief while also providing the ultimate comforts fit for the traveling White House -- are closely guarded by a specially trained Air Force unit tasked with its operation and protection.

As the plane marks 25 years of flying presidents, ABC News was granted an exclusive nose-to-tail tour of the plane and its super-secure hangar -- fortified behind a military checkpoint and two layers of fencing within the boundaries of the already-secure Joint Base Andrews just outside Washington, D.C.

In a briefing to prepare for the plane’s 393rd mission on Monday, a simple flight to New York City’s John F. Kennedy Airport and back, every detail and possible interference -- down to the precise location of construction and alternative taxiing routes--– is accounted for ahead of time.

“Every day is not only game day, but it's the Super Bowl,” Air Force One Commander Col. David Banholzer, the 14th presidential pilot in history, told the crew members in the planning meeting. “It doesn't matter if we're on a week-and-a-half trip around the world or just a up to JFK out and back, you always have to keep your guard up and anything can happen on any given day.”

But despite all the contingency plans, the plane’s head of security CMSgt. Daniel Jacobs conceded that the greatest threats are those that are unknown and impossible to fully anticipate.

“When we're parked out on JFK it's a national monument it's sitting out there for many people to see and it's more vulnerable at that time,” Jacobs said.

The unpredictable nature of protecting the president means that the Air Force team must constantly evolve. With the recent landing of a gyrocopter in the shadow of the Capitol and a drone that crash-landed on the White House grounds earlier this year, Jacobs said his team’s training now includes preparing for drones and other small flying devices that could pose a threat to the president.

“This week we just completed a joint-training exercise with the Secret Service, and we prepare for those exercises and those scenarios,” Jacobs said.

Whether it is a drone or a ground-to-air missile, Air Force One has an impressive array of defensive security measures to make it a flying fortress. Though many details are classified, the plane is equipped with features that allow it to repel airborne missiles and jam enemy radar. The plane also has the ability to stay airborne indefinitely thanks to a feature that makes the plane capable of being refueled mid-flight.