Radar mountings in the nose of the Lockheed Martin [LMT] F-35 fighter are different for the current AN/APG-81 by Northrop Grumman [NOC] and the future AN/APG-85 radar, also by Northrop Grumman--a difference which has helped complicate fielding of the new radar which was to deliver with F-35 Lot 17 but may now instead deliver later, possibly in Lot 20 in the next two years. "The APG-81 is different than the APG-85, and therefore delivering the aircraft, as currently configured, with…