I think lots of early X planes were made due to our lack of understanding in aerodynamics and aircraft design.
We do now understand classical aircraft, large aspect ratio wing, relatively narrow fuselage and tail planes at the aft end of the fuselage, and several non-classical ones, but several are not yet sufficiently investigated and are therefore only available to very brave designers and might not be acceptable to the management of the company. One example is the joined wing concept that has been promoted for a long time but is only now getting traction in Chinese UAV designs. Another is the STOL tilt wing concept which was used in the German airliner design BV 144 (
) a prototype of which was built in France and first flew after the war in August 1945. This could provide a much cheaper transport than V-22 Osprey, able to make use of roads for take off and landing but lacking vertical take off and landing, if combined with a cross-shaft between the turbine engines and possibly with contra- props. A third is the tail boom mounted on the wing tips.
There are more concepts that deserve to be investigated and to be made available to the World. A main reason every aircraft designer in the World needs to learn the English language is to be able to make use of the immense amount of information about these matters provided by NACA and NASA over the last century. If China were to provide missing information in Chinese they would also have to learn Chinese.
