Originally Posted by 4wdwrx
I'm not talking about actually flying. The airplane has been invented long time ago. I'm talking about hover/levitate a few foot substituting for tires (not a hovercraft but similar to ones in the new Total Recall).
This would remove a lot of friction. Definitely an antigravitation device would be a must. traditional jet engines used in vertical take off use too much energy and difficult to maintain flight.
This is crazy stuff i'm talking about and would need serious break through research in magnetism, electromagnetism (who knows, someone might already be researching this)
Hovering is standing still.
You are talking about levitation while at speed, which is a form of flying.
Whether you do that with power... which is likely insanely demanding, power-wise to constantly counteract gravity.
And merely levitating just above a surface while traveling at high speed does not offer much assurance from obstacles that are common along the ground.
Not only that, but yaw control authority to turn is reduced, and roll would be a problem, unless the levitation height is higher that the vehicle's maximum width. Aircraft (which anything suspended above the ground could be considered a form of aircraft, without ground contact) don't yaw on a dime.
Pitch variation would also be problematic, as nose-down would likely create an aerodynamic force that would force the vehicle to nose into the ground, and nose-up pitch would likely produce so much lift, that the vehicle would flip end over end, like a Lemans Prototype Racer on a bad day.
Ekranoplans are ground-effect flyers, but even they require wings, and are usually intended to cross bodies of water, where there aren't man-made and natural landmark obstacles.
Ground contact and friction are what produce the control authority that a car has.
Without it, a hovercraft usually has to maintain lower speeds, and higher speed aircraft have to maintain altitude above obstacles on the ground.