If "all flying rudders" for LSA aircraft need 33%-40% less area than a typical vertical tail (stabilizer and rudder) ( subject to final stability analysis), what about "all flying elevators" (stabilators) with:
- anti-servo trim tab?
- no anti-servo trim tab?
I understand anti-servo tabs add stability to "all flying rudders/elevators" by auto-centering.
According to a design guide from Zenith: Flying on Your Own Wings, by Chris Heintz, pg 229:
The vertical tail area should be 12 to 15% of the wing area (15% if the rear fuselage has a small rounded section, and 12% if the rear fuselage has large flat sides). These percentages may be reduced to 7% and 10% for an "all flying rudder".
A wing is a wing, no matter what attitude, whether it be horizontal or vertical. So I should be able to reduce my horizontal tail area by roughly 33-40% when using only a "all flying elevator" (stabilator) (subject to final stability analysis). Is this correct?
My personal view is that a Zenith can fly a lot slower with an all flying rudder, 39 mph or slower, and that is why Heintz recommends that based on the type of aircraft he manufactures: basically LSA types, @ 1320 lbs MTOW, 39-4 5mph stall speed. Somewhere I read that a Zenith 701 won a STOL competition in Australia with a 25' takeoff, and that a 3 second takeoff is common and by the time you reach full throttle, you're aloft albeit still in ground effect.
I understand the Zenith CH200 had a classic vertical tail, but that most or all current designs use an all flying rudder.
Summary: So I assume that Heinz's above recommendation is for sizing a rudder at a 39mph stall speed which would need to be bigger for slow speed handling than for a plane that stalls at 60mph.
Revised question: at 39 mph would an "all flying" elevator be more efficient, thus letting it be 33% to 40% smaller?