On May 7, 6:01*am, wrote:
On May 6, 9:40 am, WingFlaps wrote:

Dan, you keep trying to pick up the wrong end of the stick.
I'm not talking about certification. For example, *in the FARs does it
describe how the stabilator chord changes with trim positions?
Certification results from practical demonstrations of plane handling
and flying not theoretical aeronautical discussions -or is that not
so?

* * * * * * The FARs don't care how the chord changes. They don't care
how the engineer achieves the flying qualities and strength they
demand for certification. They just set certain parameters that must
be met, and the engineers design an airplane that complies with those
parameters.
* * * *If the trim tab damaged the effectiveness of the elevator so
that the control surface stalled, or lost authority to the point that
the parameters could not be met, certification would not take place.
Period. Your arguments are specious.

There are lots of factors that may _promote_ a surface stall (e.g.
rivet heads) but that doesn't mean the surface is not going to do it's
jub well enough to let the plane fly and pass the certification test.
It's similar to the (better known) idea that rivet heads may promote
flow separation -but that does not mean that riveted planes can't pass
certification does it? Understanding the effect of the trim tab on
the elevator may prevent the mistake of thinking it ihas _no_ effect
on elevator performance. It may be a philosophical discussion but
that does not mean it's specious.

Cheers