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# Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/19/2020 2:17 PM

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#1

### Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/19/2020 3:37 PM

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#2

### Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/19/2020 3:44 PM

That style of airplane is designed to be slung forward... like with a fixed mount and 20 feet of bungee cord or surgical tube.

Hook, pull, release.

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#3

### Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/19/2020 10:22 PM

After the launch phase, the remaining distance covered is determined by the lift to drag ratio. By similar triangles, you can prove geometrically that distance/altitude = lift/drag as shown by the diagram below:

To maximize glide distance, minimize drag, make surfaces as smooth as possible. The balance of the aircraft will determine its speed, and at some speed, the lift/drag will be minimum. Adjust weight distribution, this will require trial and error probably.

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#4

### Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/19/2020 10:39 PM

Consider adding some small elevator trim tabs into the aft portion of the wing on each side. Must be identicaly trimmed or will cause turns. No weight penalty as they can be cut into the aft portion of the wing. Pins and thread can set trim angle. Another idea is to launch when there are thermals present. I watched a paper airplane made from an 8.5" X 11" sheet of paper launched from a model rocket as a parasitic glider catch a thermal and was lost from sight and still going over 5 mi away!

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#5

### Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/19/2020 11:36 PM

Back in the late '50s, I took a small (≈10" long & wingspan) balsa glider to a fire lookout at the top of the Sierra Buttes, about 50 mi. north of Lake Tahoe. There is a long vertical face on the east side, so on sunny days a significant updraft forms in the early afternoon. I threw the glider out into that updraft, and watched it spiral upward until it reached a layer of air moving rapidly to the East. Using the huge binoculars of the lookout, I was able to (barely) watch it pass over the next ridge, about 12 miles to the East.

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#6

### Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/19/2020 11:41 PM

The Clark Y airfoil is a simple airfoil that you can make. There are better shapes, but harder to cut. We used to use cardboard or wood templates and a hot wire to cut the Styrofoam airfoil shape. Covering with paper or aluminum foil will greatly stiffen the wing.

http://airfoiltools.com/plotter/index?airfoil=clarky-il

Smooth surfaces really help.

As previously noted by other posters, weight distribution and elevator tabs allow trimming.

Gliders (sailplane - differentiated by being more efficient and can gain altitude in thermals) generally have long slender wings that provide higher lift to drag.

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#7

### Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/20/2020 1:01 AM

First, you got to get a giant hand,,,

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#8

### Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/20/2020 7:39 AM

Check...

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#9

### Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/20/2020 10:03 AM

Has this guy ever made paper airplane? The reason I ask is that his plane has a "T" wings to body profile. When you fold a paper airplane you naturally get a "Y" profile. Oh my an airfoil. Also it's easy to fold the wing tips to add Rutan devices.

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#10

### Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/20/2020 1:47 PM

What I was able to see from the video is that the plane seemed to do a good job of going forward in a straight path, but appeared to have a tendency to nose up a bit and then mush, stall or reverse slip. It also had a tendency to nose down and keep going further down.

A previous comment about adding dihedral might be appropriate, although the deep keel on the plane adds a little bit of effective dihedral by masking the raised wing, combined with a lowered center of gravity due to the deep keel.

It looks like it needs the center of gravity just a bit further forward to cause the nose to drop when speed slows. Some added reflex to the wing trailing edge would tend to push the plane to nose up as speed increases and decrease the nose up when speed decreases.

The foam flitter flies better than I would have guessed it would.

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#11

### Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/21/2020 12:01 PM

You could add a small pair of foam-board, canard-type, winglets to the nose.

If their vertical cross-sections were symmetrical, the over-all center-of-gravity could be moved slightly foreward, without adding more nose-lift...

Start by adding a little too much foam canard weight, and trimming it down by-trial-and-error, to get the balance back toward optimum...

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#12

### Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/21/2020 2:52 PM

'illigitimi non carborundum...'

illigitimi = bastards

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#13

### Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/22/2020 1:22 AM

Why not incorporate the design characteristics of the world record holders....

Both the longest distance, above, and longest flight duration, below....

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#14

### Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/22/2020 1:41 PM

If you just want to move the center-of-gravity a little farther forward, all that is needed is to:

- start from the bottom of the rear of the existing airplane, and measure up the tail a few inches, striking a short mark on the tails' edge;

- draw a straight line from that mark, forward and pararllel, to the top surface;

- carefully cut off the resulting triangular volume of foam-board;

- test-fly the modified airplane, and;

- repeat the process, until sufficiently optimum performance is reached.

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#15

### Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/25/2020 2:38 PM

Tn airplane has 4 forces acting on it: Thrust, directed forward, drag directed aftward, lift directed upward from the center of lift, and weight directed downward from the center of gravity. A glider, of course, has no engine and thus no thrust. The glider flies slightly nose down so that a component of the lift is directed forward opposite drag.

Example airplane gliding (no engine thrust), lift force tilted forward by the angle of glide.

In the paper airplane, the center of lift is in the plane of the wings. Its location can be found by making a pattern of the wings on a piece of cardboard and then locating center of gravity (balance point) of the cardboard pattern.

The center of gravity is about in the center of the plane and can be found by balancing the plane. The center of gravity will be below the wing area. The weight force acts at the center of gravity and the lift force acts at the center of lift, so the two forces will keep the plane upright. If the center of gravity is slightly forward of the center of lift, the plane will balance slightly nose down, which is desired for stable flight.

The center of gravity below the center of lift will also provide roll stability, but additional roll stability may be added by tilting up the wings (dihedral).

The swept back shape of the wing and the fuselage shape will provide yaw (right-left) stability if the plane is moving forward.

For speed stability, the trailing edge of the wings can be bent up slightly. As the speed of the plane increases, there will be a force that noses it up, slowing the plane down again. This should be combined with moving the center of gravity slightly more forward.

For this design of airplane, the primary factor controlling stable flight is the relationship of the center of lift and center of gravity.

http://isaac.exploratorium.edu/~pauld/activities/flying/PaperAirplaneScience.html

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#16

### Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/27/2020 12:07 PM

NOW I understand center-of-lift. GA from me.

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#17

### Re: Flight Improvement Suggestions Requested for Awesome Giant Hand Launched Glider

10/28/2020 10:11 PM

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