Aerospace manufacturer Lockheed Martin Corp (NYSE:LMT) stock is gapping lower today, after a U.S. Defense Department procurement request sent to Congress asked for 24 of the company's F-35 jets for the U.S. Air Force, compared last year's forecast of 48. The halved order has traders eyeing defense sector peers Northrop Grumman Corp (NYSE:NOC) and RTX Corp (NYSE:RTX) as well. LMT was last down 5.4% to trade at $451.30, pacing for a third-straight daily drop as it dives below recent support from the 20-day mo ...