<p>As concert-goers stream onto Northerly Island this weekend to catch a show by the South Side’s own Chief Keef at an outdoor theater, they may not realize there used to be a different type of buzz there: Of planes taking off and landing at a little airport called Meigs Field.</p><p>But Chicagoans of a certain age may recall its controversy: The general aviation airfield, with a single runway and a stubby control tower, occupied the artificial island starting in the late 1940s, ultimately catering to aviation enthusiasts, along with business and government types gaining easy access — via jets, prop planes and choppers — to the Loop.</p><p>At least until 2003.</p><p>That’s when Chicago’s then-mayor, Richard M. Daley, abruptly closed the airfield by quietly ordering in heavy machinery to carve giant X marks in the 3,900-foot-long runway, rendering the site inoperable. There was no advance notice, except perhaps a backdoor tip off to select powerbrokers.</p><p>Daley explained that it was a post-9/11 security measure, with the airfield in the midst of all those high-rises, and he insisted he couldn’t jeopardize Chicago’s safety and security — though the explanation was never quite credible.</p><p>He’d wanted for years — well before 9/11 — to convert the plot into open green space, only to face resistance from flying advocates, businesspeople and state officials including then-Gov.