An experimental development of the ES-31 Heavy fighter aircraft. Obviously, this variant breaks the original stealthy characteristics of the original ES-31, however, due to the fact that the structure of the aircraft is almost exactly the same as the ES-31, it has kept the same category number, but has been marked with an 'X1' to signify the fact it is the first experimental aircraft of the series. Flight controls are largely similar to the ES-31 with thrust vectoring again being engaged with small amounts of the VTOL slider. Another ES-31 variant is under development, with some features taken from this and added to the original stealth airframe. But, until then, happy flying!!!