Some interesting info on Pre-WWII aeronautics research…
In 1934 Henri Coanda experimented with a VTOL flight effect that he named the Coanda Effect.
A single turbine forces air over a domed hull producing lift. The effect was known since before 1910.
The US army built a few prototypes and tested them, but they were too unstable, funding ran out and they stopped development.
- Coanda effect craft look exactly like the classic flying saucer shape
- Sightings of UFO’s of this shape do not pre-date 1934.
- Coanda effect craft were built and tested by military and private companies worldwide.
http://en.wikipedia.org/wiki/UFO_sightings_in_United_States
a nice Coanda vehicle vid
GFS Fenstar ‘flying saucer’ Coanda-effect UAV
Some similar techs (not Coanda):
Piasecki VZ-8 Airgeep
Piasecki VZ-8 Airgeep]Israeli Piasecki VZ-8 Airgeep
http://www.militaryphotos.net/forums/showthread.php?162172-Coanda-effect-VTOL-UAV-test-flight
http://www.unrealaircraft.com/wings/cv_flapjack.php