The original note, as written at the time
A novel, well designed aircraft whose wings are filled with helium gas. These wings will definitely have to be considerably wide and large in relation to the fuselage.
Ongoing development
An aircraft whose wings are filled with helium — which means the wings have to be considerably wide and large in relation to the fuselage.
The proportion is the design and it follows from the physics. Helium gives about a kilogram of lift per cubic metre, so to matter at all the wing must enclose a great many cubic metres, and a wing that encloses volume is a wing that is thick. A thick wing is a slow wing.
So the aircraft that comes out of this is not a fast one. It is a machine with an enormous, light, voluminous wing and a small body, and that is a recognisable class: it is closer to an airship with wings than to an aeroplane with buoyancy.
The honest trade is what makes it worth designing. Buoyancy removes weight continuously, which is what a rotor or a wing must otherwise do every second. The cost is drag, and drag is paid continuously too. The question is whether the weight removed is worth more than the drag added, and the answer depends entirely on how slowly the thing is willing to fly.
At low speed and long endurance — surveillance, patrol, cargo to a strip that is short or rough — the trade can be favourable. At any speed above a few hundred kilometres an hour it cannot.
The interesting design problem is not the lift. It is whether a gas-filled wing can survive a puncture in flight, which means compartments and a leak-tolerant structure.
Buoyancy is cheap lift and expensive drag. Know which one you are buying.