(Koopas Ly) wrote in message . com...
Me again,

Va seems to be only intended to protect against excessive positive
load factors. What about negative g's?

Can I find a Va for negative design load factors (-1.52 g) for the
C172SP anywhere?

Reason I am asking is that I want to try the "floating pencil" trick
next time I fly but I don't want to shove the stick fully forward for
fear of breaking something. I am not looking to induce negative g's,
only zero g's and zero lift. Any pointers on entry speed and power
settings? Is it easier to perform if you induce a gradual +1 g steep
climb similar to a departure stall maneuver, then upon hearing the
stall horn, give it good nudge forward on the stick? I've heard that
your airspeed may indicate well below stall, but again, your stall
speed does approach zero as your load factor goes to zero.

It can be done from cruise speed. Pull up into a shallow climb,
then start pushing forward, increasing pressure until the pencil comes
off the panel. It'll feel like negative G's but isn't. The only stress
on the airplane occurs when you pull out of the shallow dive created
by the maneuver. You don't have to get the nose way up or down at all,
and it doesn't require abrupt, or anywhere near full, control inputs.
Kids love it.
MAKE SURE EVERYTHING IS TIED DOWN IN THE CABIN. Floating cargo
can depart through a window or it can come down hard on the pullout
and damage something.


Dan