Can only echo Engines' fine post and add that the CVSG(R), CV(R) and CV(F) requirement definition work was all aircraft-agnostic, in that it was not centred around STOVL JSF (or SSF, CALF or other predecessors). While the advantages of the JSF programme in terms of exploiting UK STOVL were acknowledged and it was assumed up until the late 90s that STOVL = smaller, cheaper ship, CTOL and STOBAR options (and variants thereof) were treated as equally valid.