So this is where we stand going forward into '24... the outline I like, it being the most practical compromise from every point of view. Nonetheless the most recent flight-tests have illustrated that in order for it to fly successfully as an X-8 configuration the airframe has to have sufficient rigidity between upper and lower quads. This costs a good deal if it is to involve the use of aviation grade alloys or else carbon-fibre at each turn of design and manufacture.
At the same time, to benefit from the single-failure redundancy that X-8 configuration affords commercial drones, a power-to-weight ratio of almost 3:1 is required; or so I'm told by people wiring, tuning and flying these things. That's also prohibitively costly to implement in terms of the required equipment and not least, in terms of the outlay on the certification that it would require in Europe and the UK, where Part 103 does not apply. It is altogether disingenuous to take advance deposits on personal air vehicles for use in regions where they are illegal to operate, but this does not dissuade most of them from doing so whilst public and investors remain ignorant of the fact.
There is thus a cogent argument to scale up by way of baby-steps and re-design the same outline for operation within ground-effect. It requires certification neither here nor there, serves as a developmental step in the right direction and proof-of-concept, whilst at the same time reducing the cost of development considerably.
This is not least because ~ as I've said all along ~ it makes eminent sense for a lower quad to be optimised for thrust and an upper for direction. The bulk of energy is used by eVTOLs in the hover by the cycling of RPM in order to preserve stability, a fact that could be capitalised upon by a larger set of motors and propellers around the base of the airframe being limited to constant operation at a higher RPM.
Thus if we are going to enlarge the scale to adult-size then it's as good an opportunity as any to reconfigure both the machine and me for flight around ground-level. We live for better or for worse in a world increasingly subject to fire and floods, both of which offer obstacles to conventional means of mobility in extremis.
Shoulders to the wheel, anyone?
