Ok, I have only a vague recollection of my school physics lessons so I have no idea if this is feasible or not:
A helicopter or similar device work within a sealed shell, something like the shape of a UFO which completely surrounds the helicopter, attached to the body allowing the blades to rotate inside. Obviously the shell would have to allow air through from all directions in order to allow the copter to fly, but this could be done in a stylish way using meshes or something so that you couldnt see the helicopter from outside. Whats the point of this? Just to create an authentic looking flying saucer that can hover and fly in any direction, but within any visible means of propulsion. It could be used for tv, films, outdoor events like music concerts, and childish UFO pranks. And it would just look cool.-- HowardMarks, May 29 2001 like this? http://detnews.com/history/ufo/ufo2.htmscroll down for the pic. [mihali, May 29 2001, last modified Oct 21 2004] Electromagnetic IFO http://www.sciam.co...first-flying-saucer [theircompetitor, Jul 26 2008] It'd be pretty noisy though. I'd prefer spookily quiet UFOs using the same principles you thought of (hidden propulsion system etc.), but with balloon/airship technology instead.
Then again, maybe people prefer their UFOs noisy...has anyone done market research on this matter?-- -alx, May 29 2001 Isnt there some kind of system thats already been devised, where soundwaves of a certain frequency are used to counteract certain noises made by engines etc.? Surely this technology could be utilised to make a silent, or if not quite, an eerily whirring type noise?-- HowardMarks, May 29 2001 Or maybe you generate a sound that is loud enough to cover the chopper blade sound, and which does not suggest a means of propulsion. If you really want to scare someone, a flying saucer emitting the sound of bagpipes at 200 dB would do the trick, I think.-- beauxeault, May 29 2001 paul moller did this quite a while ago, see link for a picture. from his own accounts, it was very unstable, but he still got it off the ground and moving about. he is now trying to market the "skycar" as the world's first flying car.-- mihali, May 29 2001 mihali thats a similar idea but not really what i meant as it radically changes the basic helicopter design in an attempt to make a serious mode of transport. With my idea, it would use existing helicopter technology so would therefore remain pretty much as stable as a normal copter, yet have the appearance of being something quite different. From the outside no propellers etc would be visible, just a smooth saucer shape.-- HowardMarks, May 29 2001 As it is, a helicopter is a fairly delicate balancing act that is quite sensitive to ground effects, density altitude and relative wind. It is likely that any enclosure about the rotor blades of a conventional helicopter would not be nearly aerodynamically transparent enough for the craft to function at all, let alone safely.-- bristolz, May 29 2001 Why not just use forced air-ram jet technology similar to that used in Harriers? Combined with a large enough set of bagpipes, it should scare people for miles.-- Reverend D, May 31 2001 sounds like a RED GREEN project...does it require duct-tape?-- shelley2, Nov 04 2002 random, halfbakery