IIRC, the Spruce Goose was the first to employ multiplier hydraulics for its [massive] control surfaces. That is, whatever force the pilot applied got amped up by 10x or whatever it was, to compensate for not only the mass, but the increased forces acting on the larger control area.
Frankly, the photo reminds me of the WWII German attempt at marrying two craft together for very heavy transport.
"Frankly, the photo reminds me of the WWII German attempt at marrying two craft together for very heavy transport."
Heinkel He-111Z (Zwillig=Twin):
