earthspeedandfire

Whenever i see a large sailplane the wing is bent upward about halfway out, why

fprintf

I bet what you are seeing is the "polyhedral" of the wing. Compared to most powered planes, where sacrifices are made for maneuverability, speed, and size, sailplanes are all about efficiency. Generally speaking a plane is more stable, and easier to fly at a long distance through thermals, with a plane that has dihedral. A wing is most efficient if that dihedral is spread across the length of the wing. Therefore you often have a dihedral angle, right at the fuse, and then additional breaks further out on the wing.

Sailplanes used to be designed all around light weight. In the days of large radio gear two channel control was all they had. A plane with dihedral turns on the rudder much better than one with a flat wing, and where your control is only rudder/elevator you need a lot of dihedral.

As radio gear has become smaller throughout the years, sailplanes have used flatter wings with ailerons and flaps embedded in the wings. Aileron planes need little, if any, dihedral to turn. Therefore many performance planes nowadays have flat wings.

There is a resurgence in interest in older sailplane designs which had older control systems. There is also interest in RES, which is rudder-elevator and spoiler control. So we are still seeing lots of bent-wing planes out there.

SoCal GliderGuider

Polyheideral basic rule of thumb: 3 degrees for the first angle and 14 to 16 degrees for the second. From half to two thirds of the wing span at 3 degrees. Swept tips require less dihederal.

Polyheideral is mostly used on rudder and elevator sailplanes.

Have you ever flown RC sailplanes? You might want to come up to Costa Mesa's Fairview park and check out the RC sailplanes this week end.

teamselpats

Me and my best friend, (earthspeedandfire) both live in san clemente, but we have only just started into gliders. We both have fllying wing slope gliders, but im looking at building a sailplane this summer. What sort of place is fairview park, we might come up hope to see u there.

teamselpats

one question, what time/day, and how many people are gonna be there

SoCal GliderGuider

Saturday and Sunday mornings to early afternoon. Losts of electric activity too. Check out the Harbor Soaring Soc. web site for directions.

www.1hss.org


If you are going to come for sure I can arrange to be there tomorrow -- Saturday.