Paul R Hill, who wrote the book ‘Unconventional Flying Objects, a scientific analysis’, was experimenting with flying platforms in the late
50’s, early 60’s.
NASA describes this type of research here, where they write:
The concept was initially inspired by the “Flying Platform” design, created by Charles H. Zimmerman and Paul Hill, which showed man’s
inherent ability to control a thrust vector pushing against the soles of his feet.
A flying platform has a thrust force pointed straight downward, perpendicular to the platform. You have to set the platform in motion by tilting it,
which will change the direction of the thrust force accordingly. Tilting the platform will also lower the part of the thrust force directed straight
downwards, which will make the platform lose altitude if you do not compensate for this by increasing the thrust force.
Paul Hill discovered that a ‘falling leaf’ motion came natural, and was a nice way to lower the platform’s altitude. Each time you tilt the
platform, it will lose a bit of altitude and each time you put the platform straight again it will stay at the same altitude (if the thrust force
exactly compensates for the weight of the platform). So it is basically a landing maneuver without having to change the thrust force, enabling a very
soft touchdown because gravity is still compensated by the thrust force at touchdown.
This convinced him that flying saucers also applied a force directed straight downwards, and used the falling leaf motion as a kind of landing
maneuver that enabled subtle control of altitude and a soft touchdown without having to change their downward force.
A downward force perpendicular to the saucer also meant that flying saucers would have to tilt forward to move forward, backward to stop, and would
have to bank to make a curve.
edit on 1-4-2020 by Guest101 because: (no reason given)