 To eliminate the muzzle-flash from cowling mounted guns that could blind a pilot at night, some of the F.1 Camels used as night fighters were modified to take Foster mountings.The positions of the pilot's seat and the main fuel tank were swapped, moving the pilot well aft of the upper wing.Twin Foster mountings were fitted, and the quadrant rails were either attached to a special "goal post" bracket, or braced by a simple cross brace between them.