06/30/2011. Remarks by Johan Visschedijk: "The second B-50A contract included 45 improved versions, outwardly identical to B-50A but with increased gross weight, they were designated B-50B, c/n 15802 to 15846, s/n 47-118 to 47-162. The first was retained at the factory for test work under the designation of EB-50B and at one time was fitted with a caterpillar track-tread landing gear in place of conventional wheels.

All other B-50Bs were sent to Wichita for modification to RB-50B, in which a reconnaissance capsule containing photographic and electronic equipment and extra crew members was carried in the rear bomb bay. Range was extended by installation of the British hose refueling system and two 700 gal (2,650 l) auxiliary fuel tanks under the wings.

Subsequently 43 RB-50Bs were converted at Wichita to other specialized reconnaissance configurations before ending their careers as KB-50J tankers:

RB-50E. Fourteen modified for special photographic missions, s/n 47-119, 47-120, 47-122 to 47-132, 47-135.
RB-50F. Fourteen modified with SHORAN (SHOrt-RAnge Navigational) radar for special missions, s/n 47-121, 47-134,
               47-137 to 47-142, 47-144, 47-146, 47-158 to 47-160, 47-162.
RB-50G. Fifteen similar to RB-50F but with additional radar equipment and B-50D type nose, s/n 47-133, 47-136, 47-143,
               47-145, 47-147 to 47-154, 47-156, 47-157, 47-161."