Maybe unrelated to G 103, but I do know that the SGS 1-34 will pitch nose
up when spoiler is deployed, especially if done at relatively high speed.
(I got a big surprise once) So the lift must move forward? ('34 spoilers
are way back on the wing)

Cookie






At 04:42 01 February 2013, Larry Suter wrote:
In his article on avoiding PIO in Grob 103's,

http://www.soaringsafety.org/pilots/ic8.htm

Dean Carswell writes, "the more the airbrakes are closed, the less pitch
st=
ability the Grob will have, making a PIO more likely if otherwise
mishandle=
d"

Is there a simple explanation why opening the spoilers increases the
pitch
=
stability? Does it somehow move the center of lift further aft? I believe
i=
ncreasing the separation between the cg and center of lift is the classic
w=
ay to increase pitch stability.=20

And if that's how it works, why does the center of lift move aft? I would
g=
uess spoilers destroy the lift downwind of their location, causing the
cent=
er of lift to move forward.....

Thanks,
Larry