T o d d P a t t i s t wrote:

There is a path that, if followed by a vehicle, produces a
loop at exactly 1G. It can be visualized as a combination
of a path that accelerates downward to produce 0 G and a
path that makes a perfect circle at exactly 1 G in the 0 G
background field. At the end of the maneuver, the object
following that path would be hurtling towards the ground at
high speed (the speed the object would have reached if it
had fallen towards the ground during the entire time it took
to fly the 1G loop.) I doubt any vehicle I'm familiar with
could actually traverse such a path through air.

I agree with all of the above, Todd, except the part about calling it
a "loop" g. The following is the vertical profile of such a "loop",
flown in the hypothetical 0 G free fall that you describe, and at a
constant "loop" speed of 100 kts.

http://www.airplanezone.com/PubDir/FauxLoop.php (9 KB gif file)

Note that the Y scale of the plot is about 10 times the X scale so the
path is exaggerated in the x direction. Also note that the resulting
path has no resemblance to a loop. Perhaps you already visualized the
path, but I am sure many others didn't (including me). Just trying to
add to the knowledge.

David Odum -- email: David at AirplaneZone dot com