Future Aviation Events

[twototwenty]

Has anyone here tried/has sucess with designs on the ama glider website other than the simple simon?

[fozendog]

In the rules when it says the longest length of the launching mechanism must not exceed a certain length. Would the longest length be from the tip of a horn to the base of the handle or the base of the handle to the top of the handle?

[jander14indoor]

I'm a bit confused on what this trial event is looking for. <SNIP>

The 'event' isn't looking for anything. The writers are expecting you to solve the problem of how to make the longest flying elastic glider. Yes you will have to solve the problem of strength for launch vs weight, but that's an exercise left to the student. Hint though, the answer changes with the height of the flying site!!!

In the rules when it says the longest length of the launching mechanism must not exceed a certain length. Would the longest length be from the tip of a horn to the base of the handle or the base of the handle to the top of the handle?

If you haven't already seen this caveat, read and understand. This site is NOT the place for rules clarification. Anything you read hear is unofficial and opinion only. Even when written by one of the rules writers like me. I'm only ONE writer and my fellow writers may disagree with my opinion.

In addition, these are draft rules, VERY likely to be edited before next year. And I guarantee comments like yours will help us write better rules.

All that said, your second choice (length of just the 'handle') is the usual interpretation in AMA. But AMA interpretations aren't binding on SO, so lets be careful with that. Now to see if we can write a rule that is so clear the last minute event supervisor will always get it right.

Jeff Anderson
Livonia, MI

[chalker7]

I'm a bit confused on what this trial event is looking for. <SNIP>

The 'event' isn't looking for anything. The writers are expecting you to solve the problem of how to make the longest flying elastic glider. Yes you will have to solve the problem of strength for launch vs weight, but that's an exercise left to the student. Hint though, the answer changes with the height of the flying site!!!

In the rules when it says the longest length of the launching mechanism must not exceed a certain length. Would the longest length be from the tip of a horn to the base of the handle or the base of the handle to the top of the handle?

If you haven't already seen this caveat, read and understand. This site is NOT the place for rules clarification. Anything you read hear is unofficial and opinion only. Even when written by one of the rules writers like me. I'm only ONE writer and my fellow writers may disagree with my opinion.

In addition, these are draft rules, VERY likely to be edited before next year. And I guarantee comments like yours will help us write better rules.

All that said, your second choice (length of just the 'handle') is the usual interpretation in AMA. But AMA interpretations aren't binding on SO, so lets be careful with that. Now to see if we can write a rule that is so clear the last minute event supervisor will always get it right.

Jeff Anderson
Livonia, MI

As usual, I agree with everything Jeff says above.

[Orange714]

I'm a little confused how the simple simon plan would be at a 0-0 incidence. From what I understand incidence is if the Wing and the Stab/Tail are on the same imaginary line which is usually the fuselage right? I just assumed that the rounding down near the end of the fuselage prevented it from having a 0-0 incidence, since the Stab was lower than the Wing. So I rebuilt the glider with a straight fuselage and didn't round down the way it did in the plan. When I launch it it goes up nice and then nosedives...which means that the glider has negative incidence? Also how would positive or negative incidence be fixed? And what's a "pylon" that the article (http://legacy.amaglider.com/assets/gene ... ecret.html) refers to? Thank you so much!

[jander14indoor]

The Simple Simon fuselage starts as a simple rectangular strip. Then its cut away on TOP behind the wing. The wing is glued directly on top, the horizontal stab on bottom. If the fuse is truely straight, then the wing and horizontal stab (some call it the elevator, but technically that's only part of the stab) are parallel when viewed from the side, thus at a 0-0 incidence.

IF you glued your stab on top, yeah, you have a 0-plus something incidence (I'm too lazy to do the trig today and figure out just how much), not good. Rebuild.

If you glued it right and it looks fairly straight, and the weight is right, and the cg is right, this is where subtle trimming comes in. Being wood, things are never quite true, so you have to tweak to get that nice transition.

Fixing incidence. Rebuild, or break, adjust and reglue, or bend. Rebuild if its really bad. Break and adjust the fuse if you are at a contest and don't have time to rebuild. Skill in that used to be important to success in Wright Stuff. Bend. This is good for small changes, those tweaks I mentioned. You can bend the fuse to straighten or curve as needed if you don't try to go to far. If you are close though, a little is all that should be needed. You can also bend your stab. Curling it up or down at the rear (that elevator part of the stab) as needed.

Oh, and as you do all this, watch your center of gravity. If to far aft you stall and dive, are you sure that isn't what your glider is doing at the top of its flight? If to far forward you'll dive without the stall. And that 0-0 incidence means the cg location is more sensitive. Leaving that tail fat (not tapering as shown in the plan) has a strong rearward move to the cg, not good.

Pylon. Its a piece of wood that spaces the wing above the main fuselage. Many of the plans on the AMA site have one, the Simple Simon doesn't. The most obvious is the Slo-Cat plan, its even labeled.

Oh, and be careful on incidence. I list it as two numbers because the wing and stab each has its own. The glider as a whole doesn't have a negative or positive incidence. What makes it fly right is the relative incidence between the wing and stab AND the location of the cg. To make things even more complicated, properly incidence should be measured for a given surface against the local air stream. Worse still, the wing when generating lift deflects the airstream that hits the rear stab so the relative incidence isn't really what the drawing shows! Two more things. For a wing to lift, especially a flat plate wing like the Simple Simon, it MUST be at a positive incidence relative to the air flow. When it glides correctly, the Simple Simon will be nose high giving the wing a positive incidence. The stab being in the down wash from the wing will be less positive than it appears.

Jeff Anderson
Livonia, MI

[Orange714]

So what you're saying is according to the plan (Simple Simon) In order to get 0-0 incidence, the Wing has to be glued on TOP of the fuselage and the Stab has to be glued on the bottom of the fuselage??

[thsom]

So what you're saying is according to the plan (Simple Simon) In order to get 0-0 incidence, the Wing has to be glued on TOP of the fuselage and the Stab has to be glued on the bottom of the fuselage??

yes. Look at the picture, this is clearly shown in it.

[jander14indoor]

thsom said it right

Jeff

[thsom]

So what you're saying is according to the plan (Simple Simon) In order to get 0-0 incidence, the Wing has to be glued on TOP of the fuselage and the Stab has to be glued on the bottom of the fuselage??

yes. Look at the picture, this is clearly shown in it.

I just re-read my post and it seemed to me that I was very rude. Please don't take any offense to this, It was certainly unintentional. Sorry!