If the message had been understood immediately, the plural use of “planes” conceivably might have prompted Zalewski and other air traffic controllers to warn other pilots to enforce heightened cockpit security. Those pilots, in turn, might have told flight attendants to be on guard for trouble. But that’s a best-case scenario. It’s also possible that the comment would have been overlooked or dismissed as an empty boast or downplayed as a misstatement by a hijacker with limited English skills. There was no way to know, because Zalewski didn’t catch it.
