Wright Stuff C

[lechassin]

I guess biplane usually means two wings, one above the other.

Can it also mean two stabilizers, one above the other? That would be VERY useful.

A biplane refers to two wings, and wings are defined as the main lifting surfaces. In any case supervisors have a "spirit of the rule" clause, and you should anticipate that any wild idea will be summarily disqualified. For the stabilizer's surface, the organizers want it small to cause instability that we have to overcome.

If you want to push the rules, you could have hinged tip fences that hang down vertically from the stab at rest, and as soon as air flows over them, the fences fold up, effectively enlarging the stab. As the plane stops, they hang down again and would technically survive a challenge. I would still expect that to be disqualified.

Luke had his second invitational two days ago and the three-bladed prop again caused mildly raised eyebrows. He was not directly challenged, but it's clear that the event supervisors have an image in their minds of what to expect, and any deviation causes pause. Luke brought an 8cm tin can into which the event supervisor could push the nose of the plane for easy measuring, but even that needed some mild defending.

[OpticsNerd]

I guess biplane usually means two wings, one above the other.

Can it also mean two stabilizers, one above the other? That would be VERY useful.

A biplane refers to two wings, and wings are defined as the main lifting surfaces. In any case supervisors have a "spirit of the rule" clause, and you should anticipate that any wild idea will be summarily disqualified. For the stabilizer's surface, the organizers want it small to cause instability that we have to overcome.

If you want to push the rules, you could have hinged tip fences that hang down vertically from the stab at rest, and as soon as air flows over them, the fences fold up, effectively enlarging the stab. As the plane stops, they hang down again and would technically survive a challenge. I would still expect that to be disqualified.

Luke had his second invitational two days ago and the three-bladed prop again caused mildly raised eyebrows. He was not directly challenged, but it's clear that the event supervisors have an image in their minds of what to expect, and any deviation causes pause. Luke brought an 8cm tin can into which the event supervisor could push the nose of the plane for easy measuring, but even that needed some mild defending.

Speaking of wild ideas... this weekend I saw a team use 2 helium balloons as wings. It didn't go so well at the inspection station...

[CrayolaCrayon]

Speaking of wild ideas... this weekend I saw a team use 2 helium balloons as wings. It didn't go so well at the inspection station...

200 IQ move

[Little-Acorn]

I guess biplane usually means two wings, one above the other.

Can it also mean two stabilizers, one above the other? That would be VERY useful.

A biplane refers to two wings, and wings are defined as the main lifting surfaces.

Not always. In my engineering classes way back when, the wing, stabilizer, and even the fin and rudder were referred to as "wings" because they all produced lift in some quantity and direction while the plane was flying.

In fact, a number of aircraft in the early days had biplane stabilizers. The Vickers Vimy bomber, a few Handley Page designs, and even the Wright Brothers' original powered design had two stabilizers, one above the other.

In any case supervisors have a "spirit of the rule" clause, and you should anticipate that any wild idea will be summarily disqualified.

I wondered about that. Has anyone actually heard a judge try to cite such a thing?

I wonder how they would react if they tried, and someone presented them with an 8x10 glossy of Orville cranking the front (biplane) stabilizer up for dear life shortly after launch on Dec. 17, 1903. Plus a banner displaying the name of our event as "the Wright Stuff"?

[lechassin]

You could certainly try to make that fly (nyuk, nyuk).

When the 2020 specs were posted last Fall, I wanted to make a "biplane" with tandem 30 cm wings and "no stabilizer" to maximize lifting surface. I suspected it might fail based on the spirit rule, but I was curious on what grounds. It was nixed because the definition SO uses for a biplane is the accepted definition in the airplane world: a biplane has two main lifting surfaces that are at least partially stacked. Ergo, a tandem wing design, even though it has two wings, is not a biplane.

I predict SO will summarily dismiss what you heard elsewhere. They use the commonly accepted definitions, they have the power to enforce them, and AFAIK you will have no recourse.

You can post your proposal(s) in the SciO FAQs and get an official ruling, but IMO it's late in the season to do that.

[nobodynobody]

Speaking of wild ideas... this weekend I saw a team use 2 helium balloons as wings. It didn't go so well at the inspection station...

200 IQ move

hahaha wouldn't that be legal if it was 8 grams anyway?

[CrayolaCrayon]

Speaking of wild ideas... this weekend I saw a team use 2 helium balloons as wings. It didn't go so well at the inspection station...

200 IQ move

hahaha wouldn't that be legal if it was 8 grams anyway?

I don't know if that's a plane anymore

[xiangyu]

200 IQ move

hahaha wouldn't that be legal if it was 8 grams anyway?

I don't know if that's a plane anymore

[OpticsNerd]

Speaking of wild ideas... this weekend I saw a team use 2 helium balloons as wings. It didn't go so well at the inspection station...

200 IQ move

hahaha wouldn't that be legal if it was 8 grams anyway?

Short answer: No.
Even if it was 8+ grams, the balloons wouldn't have passed the chord length limit(and possibly not even the wingspan limit), so you'd be tiered. If you somehow managed to get the balloons to be confined within the wing limits by restricting their shape while still filling them with just the right amount of helium such that the plane doesn't lift or descend, that'd be an achievement worth quite a bit of recognition. But even then it still wouldn't be legal. First off, I don't think it's hard at all to argue that two helium balloons attached to a stick of wood isn't a plane, and the rules do specify that you need to build a plane. Also, even if it did count, the event supervisors could easily argue that it goes against the spirit of the competition. Any of those things would get you tiered.
So, I advise you don't try it.

[bjt4888]

I guess biplane usually means two wings, one above the other.

Can it also mean two stabilizers, one above the other? That would be VERY useful.

A biplane refers to two wings, and wings are defined as the main lifting surfaces.

Not always. In my engineering classes way back when, the wing, stabilizer, and even the fin and rudder were referred to as "wings" because they all produced lift in some quantity and direction while the plane was flying.

In fact, a number of aircraft in the early days had biplane stabilizers. The Vickers Vimy bomber, a few Handley Page designs, and even the Wright Brothers' original powered design had two stabilizers, one above the other.

In any case supervisors have a "spirit of the rule" clause, and you should anticipate that any wild idea will be summarily disqualified.

I wondered about that. Has anyone actually heard a judge try to cite such a thing?

I wonder how they would react if they tried, and someone presented them with an 8x10 glossy of Orville cranking the front (biplane) stabilizer up for dear life shortly after launch on Dec. 17, 1903. Plus a banner displaying the name of our event as "the Wright Stuff"?

Wing and stabilizer, for the purposes of Wright Stuff rules were defined in the FAQ last year. I suspect that the same definitions would apply this year if the question was posed.

Brian T