Does a RC glider always loop when launched?
No, it doesn't loop when launched correctly.
If you launch it so fast that lift is greater than weight, if will pitch up, and may either stall (as happened to me with my foam plane) or may enter a phugoid cycle where it climbs, dives, climbs again, and so on.
But if you launch it at the right speed and right angle (usually slightly down) it will fly smoothly to a gentle touchdown far away. This is the&quot;trim speed&quot; John K was talking about.
By angle I mean direction of flight, not pitch angle, or angle of attack. A stable glider will correct these as a rule.
But if your launch leaves too little lift, it will pitch down. This usually results in an immediate crash, due to the small altitude budget available.
The more lift your elevator is trimmed to create, the higher the optimum speed will be
But it must always have lower angle of attack than the wing, or the plane will be unstable or will nosedive and crash
I often threw my plane at the ground as hard as I could, just to watch it nearly crash, and then zoom up to twice my height.