The Witteman Air Liner was proposed in 1915 by Charles R. Witteman, but never built. It was touted as an inherently stable design with controls “arranged for operating by either one or two persons.” It had a planned span of 50 feet, length of 96 feet and was to be powered by two motors spinning four propellers (two pusher and two tractors), and a third turning a water screw for maritime use. Its projected climb rate was 250 feet per minute, cruise speed 55 to 65mph. It was claimed the craft could potentially stay aloft for 7 hours with a payload of 2,000 pounds.
Several goliath aircraft designs were proposed by aeronautical pioneers in the vintage aviation era. Many were just ideas on a drawing board but a few were built and flown. One notable giant was the Barling Bomber, circa 1923. Another envisioned behemoth was the Flying Aircraft Carrier proposed in 1943 by Horace Chapman Young and Eric Langlands, as reported in the February 1993 issue of Popular Science magazine. Most notably, the enormous Spruce Goose designed by Howard Hughes flew in 1947, as reported by Combatreform.org.

Witteman Air Liner.

Horace Chapman Young and Eric Langlands’ 1943 Proposed Flying Aircraft Carrier, courtesy of Combatreform.org. The February 1993 Popular Science reported on the 1943 proposal. Popular Science

Barling Bomber, Univ. of Texas, 1923.

Vintage Russian poster documenting Soviet Giant Airplane Concept.

Period magazine Modern Mechanix cover.