Hello Norch
Sounds like the big boys had money on their brains rather than LTA flight. An economic case can be made for the very large lifters if the market segment is narrowly defined.
On the other hand there's the sport market for two-person dirigibles like Santos-Dumont's early designs...
One reason from a pilot's point of view is that more blades equates to smaller rotor diameter for the same thrust (lift). When landing clearings are a big problem as in the northern provinces, smaller blade radius is preferred.
Having said that, one disadvantage is that the rotary momentum, or...
