Airport in Central Park?

An international airport in Central Park? This "proposal" sought to take advantage of Manhattan's largest "undeveloped and underutilized site" Central Park, by constructing a modern airport.

From the proposal: 

Our nation’s most densely populated urban area.. has no viable airport. JFK, LGA and Newark... are not an acceptable option for the majority of New Yorkers, requiring travel through some of the most congested traffic arteries in the nation... Amazingly, there is still a large, undeveloped and underutilized site in the center of NYC. In fact, this site has remained undeveloped for so long that many of us forget it even exists.  It’s called Central Park. Ask most New Yorkers when was the last time they visited it. Statistically that number is fewer than one visit per person per year. But how many times did those same New Yorkers go the airport? It doesn’t take long to realize Central Park squanders 843 acres of the most valuable real estate in the world. But it doesn’t have to stay this way. In the past decade residents of high-density areas the world over have empowered themselves to reclaim disused and blighted urban spaces and infuse them with new life and new sense of purpose. From London’s Tate Modern to Paris’ Promenade Plantee to New York’s own High Line examples abound of this enlightened philosophy of urban conservationism. Our regional airports are more overcrowded than ever. Millions of skilled workers are without jobs. And Congress stands ready to spend billions on shovel-ready stimulus programs to reenergize our economy and get New Yorkers back to work. Public responsibility dictates that we transform this underutilized asset into something we so desperately need today. Manhattan Airport will prove NYC no longer allows it’s vestigial prewar cityscape to languish in irrelevance but instead reinvents these spaces with a daring and inspired bravado truly befitting one of the world’s great cities.
— Manhattan Airport Foundation

If you didn't catch it reading the proposal, the Manhattan Airport Foundation (2009) was a prank. And even if there was a serious proposal to pave the "lungs of New York" Central Park is a scenic landmark and protected.