Quick question - does anyone have a rough figure for how much the lift engine and transmission weighs? I'm probably missing this having been covered previously but I can't seem to find a reference for the figure.
That 3898-pound total weight difference includes not just the fan and shaft & transmission but also the extra ducts inside the wings, whatever mechanisms opens & close those, the joints that move the main nozzle, and any differences resulting from the use of corrosion-resistant materials.
The A & B models differential with similar size/wing area (compared to the rather different C model) is 3,000 lbs. There are many variable differences otherwise in A & B due different internal structure with B 'lightened'. I guess the STOVL engine LiftFan bits and pieces weight(s) must be classified.