wannabe wrote:.........I too have been told to use the ailerons down method to approximate best lift to drag setting for short field flap
settings. ...........

Where did this "flaps down to match ailerons" business come from? I've heard this several times on this site. The flaps & aileron have different jobs, and (esp) on the barn-door-flap models, the flaps & ailerons are built with a completely different physical configuration. Who cares how much the ailerons are hanging down? If your trial-and-error testing sez you get off quicker with 20 degrees of flaps (or 30, or whatever)- go for it. The flaps can be raised back up to 10 or even zero degrees just as quick as a wink, as soon after takeoff as you feel is appropriate.

Eric

hotrod150 wrote: Where did this "flaps down to match ailerons" business come from? I've heard this several times on this site.

Sparky's Mountain Flying Bible

Swingwing wrote:

hotrod150 wrote: Where did this "flaps down to match ailerons" business come from? I've heard this several times on this site.

Sparky's Mountain Flying Bible

Say AMEN Brother ! carry your Mountain Flying Bible everywhere you fly -one copy in my flight bag another in back seat pocket of R/H front seat another on my nightstand near phone. I guess you could say this iGOOD book I use. AMEN R.I.P. Sparky Blue Skies and Tailwinds.

The flaps to match the down aileron concept comes form the aileron down stops being set at an angle that gives you the best lift to drag setting. It is just a convenient way to get the flaps as close to the same maximum lift with minimal drag setting. May not be perfect, but has proven to be a pretty good starting place for a lot of years.

The assumption here is that your plane is properly rigged within specs of course.

Those with lectric flaps can always do their own empirical testing. Ya just might determine the best setting to be a degree or so different.