In article ,
"J.Kahn" wrote:

Been researching this but can't find a direct answer:

Is the increase in nose down pitching moment from deployment of flaps
any more for a single slotted flap vs a plain flap, all other factors
being the same? If a design that used a plain flap was switched to
slotted while keeping the areas etc, the same, is more tail volume
required to compensate?

As I understand aerodynamics, the sloted flap is a means of increasing
the wing cord by using less material.
It is the increase in the cord width which allows the center of lift to
move aft, resulting in a pitch down moment.