Quote:
Originally posted by socalpunx:

I also used the Harrier reference because there are two forces at work there. First it uses downword thrust to achieve lift, and then forward propultion to achieve speed.

Try to imagine a hovering Harrier. It is hovering in mid air and then when maximum thrust is applied to forward motion it reaches speed and is no longer reliant on downword thrust to defy gravity. But by "floating" it is eliminating the need for a runway, thus no need for wheels. Yet, from a standing start, mid air, it is able to achieve flight.
It is NOT able to achieve flight from a mid air standing start. The vents gradually turn as the plane begins moving forward.

Try taking that harrier and switching the vents instantaneously from vertical to horizontal.

It's going to drop like a rock. Because there is no lift on the wings.
_________________________
"Nature has constituted utility to man the standard and test of virtue. Men living in different countries, under different circumstances, different habits and regimens, may have different utilities; the same act, therefore, may be useful and consequently virtuous in one country which is injurious and vicious in another differently circumstanced" - Thomas Jefferson, moral relativist