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Author Topic: High aspect-ratio A6's  (Read 3582 times)
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Tmat
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« Reply #50 on: June 30, 2022, 10:33:24 AM »

Doesn't the over-riding rule also apply that :-
"Projected area of horizontal stabilizing surface(s) in excess of 50 percent of the projected area of the supporting surface (wing area) shall be considered as wing area."
2022-2023 rules say the following: The total maximum projected wing area shall be 30 square inches. There is no
restriction on the stabilizer area.  https://www.modelaircraft.org/sites/default/files/Indoor_Free_Flight_2022-2023.pdf

So a true tandem with 30 sqr/in in both "wings" is doable. I guess technically, you could make the stabilizer even bigger than the wing? Hmmmm....
Btw, nothing saya it has to be a monoplane. So a biplane is ok??

Tmat
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steve-de24
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« Reply #51 on: June 30, 2022, 01:16:47 PM »

Tmat, thanks for the link to the latest rules.

Paragraphs 1,2 & 3 are rules which apply to all the AMA classes of indoor model and para. 24 apply specifically to A6.
Para. 3 is the one that stipulates how a model's wing area is calculated and that's where it says "Projected area of horizontal stabilizing surface(s) in excess of 50 percent of the projected area of the supporting surface (wing area) shall be considered as wing area."

If I have a tandem model with two 30 sq.in. 'wings'.  The rear wing area is obviously greater than 50% of the front wing area so, according to para 3, some of its area must be considered as wing area - and then the model fails by having a wing area greater than 30 sq.in.

cvasecuk, I got to the max allowable area of two 22.5 sq.in. wings by saying :-

wing area = 30 = 22.5 +7.5
tail area    = 15 = 22.5 - 7.5
the 7.5 sq.in. is that part of the tailplane area considered as wing area under para 3 rule.





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Flyguy
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« Reply #52 on: June 30, 2022, 01:32:48 PM »

Yes, the rules on A6 refer to the 'wing area', it doesn't say 'wings', so it doesn't sound like a multiple wings argument will fly, so to speak. I wouldn't mind trying a biplane, but it doesn't seem legal for A6 (or a tandem A6).

I know I never bother to look at the general rules, but I believe Steve is correct that paragraph 3 says a general rule applying to all classes is that stab area over 50% is considered as wing area, which would mean that a tandem with two 30 sq inch wings is not allowed.
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cvasecuk
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« Reply #53 on: June 30, 2022, 02:11:15 PM »

Steve, If the wing is 22.5si then 50% of that 11.25si so if the stab is 22.5si then 11.25si must be added to the wing which would put it over 30si!
Note: It says 50% of wing area, not 50% of max wing area.
Ron

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Tmat
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« Reply #54 on: June 30, 2022, 02:59:15 PM »

See the attached plan. Both wings are 29.5 sqr/in projected. It's a tandem and apparently it's legal.

Tmat
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Re: High aspect-ratio A6's
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steve-de24
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« Reply #55 on: June 30, 2022, 03:38:12 PM »

Ron,
Rereading the the para 3 rule again tells me your way of calculating the allowed tandem wing size is correct, thanks for pointing it out.
Steve
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cvasecuk
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« Reply #56 on: June 30, 2022, 04:06:32 PM »

Tmat, According to Para 3 of the rules, it shouldn't be!
Ron
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Tmat
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« Reply #57 on: June 30, 2022, 04:57:51 PM »

I'm assuming that 24 supersedes the generic rules for indoor models?

Tmat
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Flyguy
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« Reply #58 on: June 30, 2022, 11:27:56 PM »

I'm assuming that 24 supersedes the generic rules for indoor models?

Tmat
Apparently, the indoor rules hold unless the category specifies otherwise, so for A6 I think you're OK because the rules specifically refer to the stabilizer:

24.3. The total maximum projected wing area shall be 30 square inches. There is no restriction on the stabilizer area.

So, for the tandem I guess one can argue that the wing is 30 sq. inches and the stabilizer area is 100% of the wing area. As Tmat noted, it does seem to open a can of worms because why can't the stab then be 150% of the wing, for example, if there's no limit on stab size? If the answer is no, it can't be, because the 'wing' is the surface with maximum area, then that implies that the 'stab' must have less area than the 'wing', which seems to rule out a tandem - doesn't a tandem then have two wings and not a wing and a stab?

Btw, nothing saya it has to be a monoplane. So a biplane is ok??

Tmat
I agree, it seems that an A6 biplane is acceptable because Pennyplane, for example, only specifies an 18" wing (singular) limit, yet biplanes are allowed, whereas limited pennyplane explicitly states monoplanes only. A6 only specifies a wing area limit, with no comments about monoplanes, so it seems that biplanes should be allowed. If biplanes are allowed, then one can also argue that tandems are allowed because they also have two wings (nothing says you have to have a stabilizer!)

Getting back to Pennyplane, it appears that there is no exception in the rules for stabilizer size, and so the indoor rules apply and the stabilizer is limited to 50% of the wing area. I went back and decreased my stabilizer size a bit so that it's slightly under 50%, I'm glad this came up!
« Last Edit: June 30, 2022, 11:45:05 PM by Flyguy » Logged
cvasecuk
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« Reply #59 on: July 01, 2022, 05:46:08 AM »

All of this just goes to show that it is very difficult to write rules which are simple, clear and unambiguous!
Ron
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steve-de24
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« Reply #60 on: July 01, 2022, 09:18:40 AM »

Ron, I'll second that!
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Olbill
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« Reply #61 on: July 03, 2022, 09:44:05 AM »

Specific rules always over ride general rules. A6 has a specific rule that says:

24.3.
The total maximum projected wing area shall be 30 square inches. There is no
restriction on the stabilizer area.

My interpretation is that if the surfaces are different sizes then the larger surface would be considered the wing. If anyone wants to stretch that interpretation then they should be prepared for a protest.

Actually I think this should be proposed as a rules clarification in the next round of rules changes.
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Olbill
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« Reply #62 on: July 03, 2022, 10:02:04 AM »

I haven't seen the final A6 results from the Johnson City event. I heard that Rey Mazzocco and Tom Sova both had 9:45's. I couldn't really compete because all of my new 5/99 motors broke while winding. I finally got a 9:06 flying a 5 year old motor that came down with a broken strand.
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Flyguy
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« Reply #63 on: July 03, 2022, 02:25:09 PM »

My interpretation is that if the surfaces are different sizes then the larger surface would be considered the wing. If anyone wants to stretch that interpretation then they should be prepared for a protest.

Actually I think this should be proposed as a rules clarification in the next round of rules changes.

I think the tandem situation is still not clear with that rule, is one arguing that the 'stab' is 100% of the wing (seems confusing) or is it two wings? I think the better argument is that the A6 rules do not say that it must be a monoplane, so two wings, as in a biplane or tandem, are acceptable. Agreed that some rules clarification is necessary.

Getting back to Pennyplane, it appears that there is no exception in the rules for stabilizer size, and so the indoor rules apply and the stabilizer is limited to 50% of the wing area. I went back and decreased my stabilizer size a bit so that it's slightly under 50%, I'm glad this came up!

I read that wrong, here's the rule: "Projected area of horizontal stabilizing surface(s) in excess of 50 percent of the projected area of the supporting surface (wing area) shall be considered as wing area."

So, the rule doesn't limit the stab size to 50%, it simply says that any area over that is considered wing area. Given that there is no wing area limitation in PP, the stab size shouldn't be limited.


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Olbill
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« Reply #64 on: July 03, 2022, 09:09:15 PM »

If you made an A6 biplane then the total of the two wings would be limited to 30si.
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Flyguy
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« Reply #65 on: July 03, 2022, 11:42:16 PM »

I don't see why. Are you saying that you can't use two 30 sq. inch wings in an A6 biplane, but you can use two 30 sq. inch wings in a tandem, with the workaround that it's a '100% stab'? Not sure that makes sense.

I'd argue that you can do an A6 biplane, here's why. Cutting and pasting from the rulebook for Pennyplane, the wing specification is:

"21.2.3. The projected wingspan, measured perpendicular to the motor stick, shall not exceed 18 inches (45.72 centimeters)."

Biplanes that do not exceed the 18 inch limit have been allowed for years. That's probably why the limited PP rules explicitly say it's limited to monoplanes.

The A6 wing specification rules say:

"24.3. The total maximum projected wing area shall be 30 square inches. There is no restriction on the stabilizer area."

So the only difference from the PP rule is that the projected wing area is limited to 30 square inches, instead of limiting the wingspan. So it seems that biplanes that meet the wing limitation, as in PP, should be allowed, why not? That also solves the tandem problem (two wings are allowed) rather than arguing that a 100% stab isn't really just another wing!




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Olbill
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« Reply #66 on: July 20, 2022, 06:25:56 PM »

I thought my experience at the Van Dover contest at the ETSU Minidome might be interesting. It was a rough contest for me. I took 7 new 5/99 motors along with a number of old motors. When I started flying A6 my motors were all breaking at something on the order of 60-70% of what I needed. I haven't figured out exactly how many broke but I used most of the A6/LPP time slot breaking motors. I finally decided that it was no use continuing with this process so pulled out a 5 year old motor that was close to what I needed. I managed to get a full torque wind on this motor and launched what would be my last attempt at A6. The flight was very nice but landed at a little over 9 minutes. When I removed the motor I found one strand was broken in the middle which obviously cost some time in the cruise and descent.

I also evidently picked the wrong one of my two models for the high ceiling Minidome. On an early attempt at close to a full torque launch the model turned right and spent about half the flight turning right. It finally changed to turning left and landed in the grand stands. From that point on I used my old trick of twisting the fuse for 15 seconds before launching.

Thanks very much to Dave Lindley for making the trek to retrieve my errant flight!

My take away from what was a disappointing outcome is that my model is not quite outclassed yet. I wound up in third place behind a nice 9:47 by Rey Mazzocco and 9:45 by Tom Sova. Young Alex Welter took the 4th spot with a very nice 8:05 and another Senior record. Alex flew a copy of my model. The last time I flew at this site was in 2012 when I set the Cat 4 record at 11:02. Until the new models get close to that time I'll probably keep my models the way they are.
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