On 2/19/2017 5:14 AM, J. Nieuwenhuize wrote:
Side sticks seem pretty popular in powered aircraft. Personally like them.
In sailplanes they have the additional advantage of allowing either a
smaller cockpit (less drag) or more room. Diana, HP18 and several older
designs have them.

Yet, they seem highly unpopular. Why would a well-designed sidesticks not
be liked, just because it's different, or are there reasons I'm missing?

Occam suggests one should never overlook the power of "popular/inertial
thinking," but that noted, and based on 2000 hours in a side-stick-equipped
sailplane...

Unmitigated Pros:
- Unrestricted lap space (*I* like it!)

Double-edge swords:
- slider in pitch (not pivoting at base...quite noticeable on first flight;
strictly a conceptual difference thereafter. But given the light
elevator/all-flying-tail forces, part of me has never quit wondering how a
"pivoting implementation" in this ship woulda compared.)
- relatively high roll forces in my ship's implementation, compared to pitch
(and rudder) forces, so definitely "a different feel" from the vast majority
of sailplanes out there; not inherently dangerous, but..."quirky?"
- neutral aileron at "some angle" to the cockpit wall (i.e. not
vertical/"obvious"). After the "controls free?" part of my checklist, aileron
neutralization done by centering the stick between the limits of its lateral
throws, as distinct from centering it vertically as most pilots probably do
"without thinking." Dealing with T.O. crosswinds/gusts is as intuitively
obvious as any center stick implementation with which I'm familiar.

Kinda-sorta related, Dick Johnson noted this particular ship's "neutral stick
position" implementation had possibilities for uncommanded roll inputs under
high/low-G inputs (think rotor turbulence), but I've never found that an
issue. This may be somewhat a function of aileron forces, too...

As for pitch, normal in-flight pitch changes I find most smoothly met by how
much I curl my fingers. Though the stick has "quite a range" of pitch throw,
normal flight uses very little of it...mostly (in my experience) occasionally
on takeoff in very gusty conditions.

I've seen/helped-rig other side-stick-ships (Diamant HBV, HP-18), I don't know
whether they were "sliders" or "pivoters" in pitch, but I imagine any
side-sticker would have the beer-around-the-campfire "pitch/roll funkiness"
available for opinionating.

As a natural right-hander, I've often imagined adapting to a left-side stick
(think many powerplanes) would require far more "mental adaptation" on my part
than did adapting to my Zuni's right-side-stick. Maybe some Airbus-driving
glider pilots will chime in?

FWIW, I transitioned into my side-sticker with 400 total hours and zero
outside checkout advice, and quit thinking about it "being different" within
two or three flights. Over the years for that matter, it's never been much of
conversation starter in BS sessions...though I suppose that option is always
there depending upon one's personality.

Bob W.