It seems odd to me that normal helicopters have rotor blades whose downwash is obstructed by having a big wide fuselage beneath them.
Today’s invention is a helicopter with a blade-like backbone which does not obstruct the airflow downwards.
This would have a low cargo-carrying capacity, but, with a pressurised cabin, it would be useful in eg very high altitude mountain rescue applications, where efficient downforce is at a premium in the thin atmosphere.
