RE: [Flightgear-devel] Turn ball fix & JSB notes

[Jon S. B. <js...@ha...>]

> > In any case, I believe the accelerations the pilot feels should be the
> > acceleration of the center of the vehicle (total acceleration in local
> > coords including gravity)
> > [...]

> Ack, no.  That's the bug!  Think about it: what's the total
> acceleration in local (!) coordinates of an F15 in a 9G turn?  Well,
> this second, the air is flowing directly at me at 260 knots.  It was
> doing that last second too, and the next second will be the same.  So
> the acceleration is zero.  Bzzt.  The acceleration is 9G, but you
> can't see that in the plane's (accelerated) reference frame.  You can
> ONLY see that acceleration with reference to the ground (or another
> unaccelerated) reference frame.

No. I was correct. We may be confusing local coords with body coords. THe
acceleration the pilot feels is:

acceleration of aircraft cg in local coords

+

w X (w X r)

Definition: Local frame = world frame ... sort of)


I'll respond more later. I am being called for dinner.

Jon