When I apply flaps in my Archer, I trim down some. This would indicate
to my that I am reducing the "down lift" of the tail and reduce the
posibility of tail stall. Yes/No?

Chuck

BDS wrote:
"Peter R." wrote

No. I can visualize how flaps will disturb airflow over the horizontal
stabilizer of high wing aircraft, but I am having difficulty visualizing
how airflow over the horizontal stabilizer of a low wing is disturbed by
the lowering of flaps.

It isn't about disturbing the airflow over the stabilizer.

The tail provides "downward lift" to offset the fact that the center of lift
of the wing is behind the cg. When you lower the flaps you move the center
of lift of the wing even further aft, and this means the tail must work even
harder. If the tail is near stall due to icing, lowering the flaps may
cause a full tail stall which will result in the nose pitching down quite
severely. You probably won't be able to recover because the technique is
totally different compared to recovering from a normal wing stall and the
altitude loss can be dramatic even when proper technique is used.

The NASA video is highly recommended viewing.