FORT RUCKER, Ala. -- From a helicopter that flew presidents, like John F. Kennedy and Dwight D. Eisenhower, to one of the first planes to dog fight over the skies of France in World War I, the U.S. Army Aviation Museum depicts the history of Army Aviation.

But of the 80,000 square feet of Aviation history that is showcased throughout the museum, the story of Army Aviation isn't just told by what people get to see, but also what they don't get to see.

Of the vast collection of aircraft and memorabilia that the museum houses, there is an even larger collection that encompasses more than two thirds of the museum's entire collection -- in storage -- that tells the story of the evolution of Army Aviation and how it was shaped into what it is today, according to Robert Mitchell, museum curator.

The collection has been accumulated over the last 60 years, and due to space constraints, the museum is typically limited to showcase aircraft that were in the Army's operational inventory, but that doesn't negate the importance of the pieces sitting in storage.

"A lot of the aircraft that are in the collection, visible or otherwise, are part of the evolutionary development of the helicopter," said Mitchell. "A lot of those pieces had a tangent to some type of paradigm shift in the thinking in the Army."

One of those pieces was the Lockheed AH-56 Cheyenne attack helicopter, which was developed in the 60s. It would have been the flying fortress of attack helicopters that was designed to deliver what Mitchell called the "Sunday Punch."

"The Cheyenne was a definite departure from the normal thinking in the Army and it kind of pushed the attack helicopter into a different realm of capabilities," he said. "It's a helicopter, but it was designed to do things that a normal helicopter wasn't designed to do -- be fast and be the big gun on the battlefield."

Prototypes were made of the Cheyenne and a production contract was awarded, but the aircraft itself never saw service. It's because of aircraft like the Cheyenne that eventually led to the development of attack helicopters like the AH-64 Apache used today, said Mitchell. The museum has two in its collection.

Other less influential aircraft, such as the XH-26 Jet Jeep helicopter, sit in the storage collection, as well. The Jet Jeep was designed to reduce weight by reducing engine size and adding turbines to the rotor blades, said the curator. The collection even includes an inflatable airplane.

Although many of these aircraft never made it past the experimental or test phases, Mitchell said that their place in Aviation history is no less significant.

When looking at the collection, it's clear how much trial and error went into developing Aviation throughout the years, and without that trial and error, the helicopter would not be where it is today, he said.

"These things have to be tried, otherwise you'd never know if it would work or not -- that's why these pieces are important," said the curator. "Think of the residual learning that the Army gleaned from these designs. There might have been something in the testing that showed that they can adapt a certain aspect to another aircraft that we never would have known about had they not tried it."

It's because of that significance that Mitchell said it's important to procure these pieces and preserve them until they are able to one day be viewed by the public. But procuring these aircraft is no easy task.

"The problem is when you talk about collecting [in these terms], unless you're intimately familiar with the Army and its procurement and testing programs, you really don't know when they get done with something," he said. "You have to constantly be asking the questions about the programs in order to stay up on these things because once it's gone, it's gone."