Back in the "old days" Jim Kirkland published the best , most comprehensive
procedures ever for trimming an airplane before the computer radios made this
a lost art. He believed , and so do I , that a flat stab has a dead spot around neutral
and an airfoiled stab has more positive control in all its movement. This dead spot ,
in my opinion , is why some people say the flat stab feels "softer". Back in the 70's
and 80's I built several versions of the same pattern airplane , one with a flat stab
and the rest with airfoiled stabs and I could tell the difference. Kirkland believed ,
like Dick Hanson stated , that a diamond shaped stab was just as effective as a
regular airfoiled stab. This is what he used on his Intruder that won the Nats.
If you ever saw him fly you would believe it also.
If you are taking the time to build an airplane a little extra time for the stab , I think ,
is well worth it.

tommy s