(CNN)It may be the most historic plane in the world: Special Air Mission 26000, SAM for short. Not familiar? Maybe you know its nickname. Back in its heyday the sleek, blue and white airliner was called Air Force One. This ain't just ANY Air Force One. SAM 26000 saw more historic events than any other -- ranging from the tragic to the hilarious. A national treasure, the airliner now sits in the Air Force museum in Dayton, Ohio. But you can't see it. It's off limits to visitors. For many history buffs and aviation geeks, that's a cryin' shame. If things were different, visitors could walk down the same cabin aisles where Jacqueline Kennedy mournfully sat beside her husband's casket en route from Dallas to Washington. You could stand in the exact spot where the only woman to preside over a presidential oath swore in Lyndon Johnson as commander-in-chief. Examine with your own eyes the on-board suites that carried President Richard Nixon to Beijing, where he cracked open U.S. relations with China.
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Budget cuts make ex-Air Force One, aka SAM 26000, off limits
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Expert: It may be "the most important historical airplane in the world"
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SAM 26000 served as a stage for several major historic events
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It carried JFK's casket,  hosted LBJ's swearing in, and ferried Nixon to China
In 1972, @placeholder touched down in the world's most populous nation, as Nixon forged the first U.S. ties with the People's Republic of China.