Ground Slammer wrote: ↑
Fri Feb 16, 2018 9:19 pm
With higher L/Ds spoilerons are indicated. Or Red would prefer winglets that double as dive brakes so it will pitch up too.
To be more accurate, that would be Red wanting winglets which can be the dive brakes, the sideslip recovery system, the extra dihedral, and the power steering, as needed.
Having the winglets canted outward, they provide "invisible dihedral" which is not there
until it is needed in a sideslip, or when making the landing flare. This is good, because excessive dihedral hurts the gliding performance, and winglets do the opposite, helping the glide. I can tell you, in a flare, the glider just settles down to the ground in a very good-natured manner, not at all willing to drop either wingtip. It is as if the actual dihedral runs to the top of the winglets, not to the wingtips. In a sideways dump-out, the sideslip gets self-corrected in a circular dimension. Looking straight at the oncoming glider, imagine a vertical circle above the glider that can touch the keel and the top of each winglet. When the glider slips sideways, the sideways recovery to level flight will be a radius only slightly larger than radius of the vertical circle you may imagine above the glider. The glider does not need to pitch down to recover from a vertical side-slip, or do anything unexpected, it simply slides down to the bottom of that imaginary circle as it recovers to level flight.
From the Fun & Games department: If anything is not clear above, fold up a cardboard model of the wing and winglets, hold it in a vertical bank, drop it and observe the recovery to a wings-level attitude. Ballast the model for a mushing descent, and drop it from a level position. Neither wingtip is likely to drop, in the short vertical distance of a landing flare. If your model performs like my real Fledgling in those instances, you will understand why I flew it for so many years.