(Ken Sandyeggo) wrote in message . com...
Kevin O'Brien wrote in message ...
In article , Ken Sandyeggo
says...

Yes Bernie it does. With centerline thrust, there is no force above
the vertical center of gravity to push it over. You need thrust above
the vertical center of gravity in order to experience
(once-in-a-lifetime only) a buntover. Once you do it, at least you
don't ever have to worry about doing it again.

Actually, Ken, you could still manually bunt the thing over with the stick.
Can't think of why anyone
would. The AAI redesign does seem to eliminate power pushover (the most common
cause of
bunting), and reduces the divergent pitch-recovery mode that leads to PIO (the
next most common
cause). It also takes out that long slow oscillation that RAF's have.

I have been following the AAI thing for a while... spent a couple hours with Jim
Mayfield at
Mentone... spent more time at Fondy during OSH... flew it slightly (not much).
The demonstrators
they have been using are not their new gyro but modified RAF's like yours.
Theirs is going to have
a slightly larger cabin as well.

I have a big story I'm working up on the whole AAI vs RAF thing... RAF is
demoralised, and many of
their dealers have bailed. But others are standing by out of loyalty. It's kind
of a mess.

RAF's answer is a sort of a trim vane mounted to the rotor mast, behind the
cabin. They call it the
Rotor Stabilator. Seen it?

cheers


Kevin,

I'm not a real technical bug, but you're right, I should have said
"power-pushover." I've seen photos of it. Minds that are more
scientific and knowledgeable than mine analyzed the RAF "stabilator"
and pronounced it basically worthless on the gyro forum. RAF says
that it "stabilizes the rotor." The gyro forum is down right now.
When it comes back up, I'll copy and paste the analysis of the RAF
stabilator. As far as I know, they only have 3 dealers left in the
U.S. There were four left, but the one in Florida got all his tickets
suspended for a year. (They had around a dozen just a few years ago.
They lost their New Zealand and Australian dealers also.) It was for
instructing in an illegal gyro, but he's the one that had about 4
students and a passenger die in unstabbed RAFs after taking lessons
from him in less than a year. I think you have to read between the
lines on the FAA's findings. I think that they needed to get him on
the ground for awhile someway.

My converted gyro flies like a dream now. It was a great investment
on the conversion. No more pitching and yawing all over the place.

Ken J. - Sandy A. Ghowe




-=K=-

Rule #1: Don't hit anything big.


Here are some comments by Doug Riley, a pretty knowledgeable person
regarding gyro aerodynamics, and his comments on RAF's "Rotor
Stabilator."

"It's hard to tell from the pictures just what this thing is. I'm
assuming that it's a small airfoil linked to the torque bar, with
in-flight variable incidence.

If this assumption is accurate, then it's a pleasant gadget that will
act as a semi-intelligent flight adjustable trim spring. Like the
gimbal head, such a device can produce control pressures that tend to
return the craft to a selected trimmed airspeed after a small
disturbance. Nothing that "stabilizes" the aircraft using rotor
forces can solve the problem caused by a high thrustline, however.

That's because the rotor takes a vacation during zero G events.
Aerodynamically, the rotor "disappears" when it's no longer lifting
the gyro. In such conditions, it doesn't matter in the least where
the rotor points. As a result, it sure doesn't matter whether a
highly trained pilot, or the gimbal head, or the rubber mast or the
magic trim vane is manipulating the rotor; REGARDLESS, THE ROTOR CAN
APPLY NO THRUST TO THE FRAME IN ZERO G.

If, without the rotor's restraining force, the airframe wants to flip
end over end, it's going to. The only way to prevent this is to
arrange the airframe so that it tracks straight and level in a zero G
situation WITHOUT help from the rotor. A no-HS gyro with 500 ft-lb. of
nose down force at full throttle will not track straight and level for
even an instant, once rotor thrust is lost.

A stable airframe is the key to ending the PPO."

I'll see if there are any more pertinent comments and post them later.

Ken J. - SDCAUSA