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10% rule is coming back, what the heck? Info please!

Old 03-01-2004, 11:52 PM
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dave_anderson
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Default 10% rule is coming back, what the heck? Info please!

Get ready for some multi-thousand dollar whining!

OK, I just had the displeasure of reading the content of Mike Hurley's article in Model Airplane regarding some of the upcoming rule changes for IMAC. Dont get me wrong, great article, just the part about the 10% rule coming back got me fired up. I am hoping someone "in the know" can shed a little more light on this.

A little background as to why I am perplexed (oooh, $10 word!)...
A good while back I put a post on RCU regarding the Colombo Anderson 31% Extra kit:

http://www.rcuniverse.com/forum/m_84.../tm.htm#849773

I was told and found out later through my own research that the IMAC rules at the time of starting this kit did not contain any 10% criteria. Verified further by the link to the thread above. Sooooooooooooooooooo, after a LOT of time, a LOT of effort and most importantly...a LOT of money, I finished my CA 31% Extra. YAHOO!!! I'm ready for IMAC. Imagine my suprise when I read this latest article.

My question to the "in the know" crowd is: OK, now what? I have a 31%, mutiple thousand dollar airplane that most likely doesn't meet the 10% rule (which again, was not in effect when I inquired about which kit to build). Will there be any kind of "grandfathering" for those in this particular situation? I admit to asssuming that the CA 31% Extra 300L wont meet the 10% rule due to length. Oh, I can hear the points a dockin now!

Oh, and yes, I had planned on using the airplane well into 2005 when the new rules are in cement.

How was that for some world class whining TJ?

Look forward to any and all discussion/ribbing regarding this post.

Dave
Old 03-02-2004, 07:14 AM
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Doug Cronkhite
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Default RE: 10% rule is coming back, what the heck? Info please!

I'd be very surprised to find someone not allowed to fly because of the 10% rule on the CA airplanes. To me they don't look much like an Extra 300L, but I think they're within the rules enough to qualify, and I seriously doubt any CD would not let you fly.
Old 03-02-2004, 08:53 AM
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rmh
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Default RE: 10% rule is coming back, what the heck? Info please!

Did you measure your model against certified factory dwawings?
Of course not.
Stop worrying
If it looks like an Extra-and it does -no one will complain--unless you win .
We went thru this with our EXTRA models
There was pi--ing and moaning about "it's a pattern plane - same on our early ZLINs.
Even tho the founder of IMAC said "absolutely, it is legal "
Most of the wailing is from those who just buy and fly and get trounced in competition.
I take that back-most of the wailing is from those who buy, fly (?) and never compete.

The 10% rule leaves lots of room for error or fudging or some super secret aerodynamic changes (boy, I have to see those!).
At some of the TOC events, I could hardly recognize a few models --but they passed the 10% rule.
You really have to scrw things up to fall out of a 10% rule, using almost any current ARF.
The narrowed fuselage (a dumb thing in the first place) is whre most failures of 10% will actually occur.
The old 20% fuselage rule was done for those who felt the model had to look like a 1950 's controline model.
Some imagined thing about "high drag".
Get that Columbo model out there and practice---Oh-sorry-- just one more thing .
We expect you to show up at the contests
Old 03-02-2004, 09:23 AM
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IanB
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Default RE: 10% rule is coming back, what the heck? Info please!

If we do not have rules we have chaos................if we have rules which we do not enforce we have EXPENSIVE WASTE OF TIME type chaos.

The IMAC body is right to have whatever rules they see fit to DEVELOP AND PROMOTE IMAC

The rules then need to be enforeced by the CONTEST CD's

If the real world experience then proves a rule to be unworkable then the rule ought to be changed............if not we are just kidding ourselves.

Look at the sound issue...............has anyone seen a flier be refused to fly.......few and far between I bet...........cheating by lowering the throttle in the test is well known to all and often advocated by the top pilots in IMAC. Judges and CD's know this too........

The 10% rule is an interesting one

How can you possibly enforce it?
Carry scale documentation to prove you are within limits? Imac produces a list of conforming and non conforming kits and arfs?

In Europe they just brought back a version of the 10% rule. ( there interpretation is rather more severe I believe)

Most Aeroworks, ALL CA's, ALL comp arf's, are all no longer allowed to fly unless the tail position is modified.

Now is this doing the hobby any good or not..........short term, absolutely not........longterm, debatable. In the UK I bet the numbers at comps will fall off OR they will be digging into their comp-arfs with a very sharp blade!!

We should be ENCOURAGING people to fly not PUTTING THEM OFF.



How should we stop the planes from degenerating into large pattern models.............thinking hats on gentlemen!!!!!
Old 03-02-2004, 09:39 AM
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dave_anderson
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Default RE: 10% rule is coming back, what the heck? Info please!

Mr. Hanson, I openly admit I have not checked this plane agaianst the factory dimensions. But it's painfully obvious its close, if not outa there on the 10%. I will check. I knew it sounded like I was over-reacting when I wrote it.

IanB, I am all for enforcing rules, but how often are "EXPENSIVE" rules going to change? If the 10% rule was STILL in effect when I got into this, I would have built a different plane. But, living overseas in the military, this was the best 30%+ kit I could get shipped over there.

I present these points as mine only. I'm done whining. For now anyway, hehe.

Does anyone know where I can get the factory specs on an Extra 300L? I'm gonna lop the tail off and make a 31% fun-fly out of it, hehe

I do plan on competing this year! Hope to see you out there fells!

Dave
Old 03-02-2004, 09:52 PM
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Default RE: 10% rule is coming back, what the heck? Info please!

Are there so many people showing up at contests that IMAC organizers need to find ways to exclude people?

10 percent?!?!?! I challenge any one having the ability to verify this. Rules that promote safety, fairness and enjoyment are needed. Rules just to make everyones life hard are a step backwards. If I lower the stab on my CAP 1.5 inches, will I get sent home? Will that make the difference in the final standings? That is the sort of mod that makes the plane fly better. Take a look at how F**K*D up the giant scale racing has gotten because of the never ending ambiguous rules. Here is a good rule for IMAC (or SCAT)......

1) It should look like a scale aerobatic airplane with the wingspan to fuse length ratio within 10% of scale. (No funky spinners or rudders)
Old 03-03-2004, 07:10 AM
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Default RE: 10% rule is coming back, what the heck? Info please!

The 10% rule is pretty easy to verify-and leaves LOTS of play room.
It is there to keep things looking reasonably scale like.
Lowering the stab is of questionable value -for IMAC.
Been there - but as long as the change is within 10% of scale go ahead.
Do you enter IMAC or SCAT contests?
Old 03-03-2004, 11:42 AM
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mithrandir
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Default RE: 10% rule is coming back, what the heck? Info please!

After my divorce, I hope to have time for entering some variety of Scale Aerobatics Competition...
In my area, SCAT seams to be most prevalent. I must admit that the level of seriousness on my part will be rather limited. Mostly I anticipate this being somewhat of a social event and fact finding mission!!! Attached is the sort of plane I am inclined to use... not too much of an investment, and also included is the next project I will more then likely use... a 10 pound, 78" span, OS 160 powered YAK 55.... I am in process of defining the surface model via CAD. After I get it final, I will CNC cut fuselage masters and make molds. After I settle on a good wing, I will mold that also.
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Old 03-04-2004, 11:40 AM
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Default RE: 10% rule is coming back, what the heck? Info please!

Dave,

If you give me your wingspan and length and tell me what model it is (300, S, or L) I can do the calculation and tell you if your plane is legal. It most likely is legal, 10% is a pretty big margin.

IMO I completely agree with the new rule and believe it is necessary. The rules give manufacturers and scratch builders some guidelines and keeps the segment true to it's value of flying planes that look scale but are still built like a model (and not museum piece like top gun or scale masters). But, yes I know IMAC cannot keep changing the rule every cycle. The way the rule was worded in the last cycle was IMO a mistake and should never have gone through. Dick is right about the 20% fuse rule and that big of a margin was not needed either. The 10% rule gives all of us as builders and designers plenty of room to play while keeping the planes true to our scale intentions. 10% is needed and it's fair.

The 10% rule should work more at the drawing board than at the contest. The point I’m trying to make here is that unless your plane is grossly exaggerated I doubt anyone would give it a second look, just go fly and don’t worry about it.

Dave, If you want to check your plane just give me the numbers. PM me and I can do it back channel if you like.
Old 03-09-2004, 07:51 AM
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Tom Wheeler
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Default RE: 10% rule is coming back, what the heck? Info please!

Dave,

Not to worry, I don't know of any current manufactured aircraft that do not meet the proposed 2005 10% rule. One thing to remember is that the 10% has to do with the outline of the aircraft with scale determined by the wingspan. Unlike the rules for the former TOC, there is no rule about the vertical placement of the horizontal stab. In your case of a CA 31% Extra 300L, if the wingspan is around 97" ( full scale 300L is 26.25ft so 31% is 97.65" ) your fuse can be between 77" - 93.5" long and still be considered scale ( full scale is 22.83ft so 31% is 84.92" )

Tom Wheeler
IMAC President
Old 03-09-2004, 09:14 AM
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rmh
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Default RE: 10% rule is coming back, what the heck? Info please!

Sure looks like the 10% rule caused a flurry--more of a tempest in a teapot.
I just found out that a Cassut was flown last year in competition (Giles Henderson ), so I gues it is a legal craft to fly a a model in competition??
The "catch" is that the Cassut is -in actuality - available -in plans, with a 15 ft wing or a 17 ft wing.
Further , it has been used in competition now -in racing with tapered and straight wings!
Some one will ask ? why use one of those?
If you look at it , you will see that it is really very close in layout to an Extra .
The big changes tho are that it already is "stretched, has relatively huge side area etc..
For Edge lovers,
it is also a straight LE setup (typical Cassut.)
I am including pics of two versions
now tell me which one is not a Cassut.
Note that the 3 view is of the commonly seen version- which is available as 15' wing /17'wing --16'fuselage.
Also note the airfoils in the pics.
As airfoils are not part of the 10% rule - either is fair game?
FWIW -I have one almost built -in a small size - just to see how well it really works.
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Old 03-09-2004, 09:27 AM
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rmh
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Default RE: 10% rule is coming back, what the heck? Info please!

One more thing -- for those who believe that these are only racers - guess again -although Giles Henderson flew in the primary class last year - the full scale is stressed - in one kit version 8+ 5-
I did a very small Cassut looong ago and was very pleased at how well it did transitional stuff (rolls).
As bad as it seems, one could make a big one from a Giant Stinger ----
Old 03-09-2004, 10:41 AM
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Default RE: 10% rule is coming back, what the heck? Info please!

I am not sure I understand you Dick. If the aircraft is used in speed racing competition, it does not make it legal for IMAC. A legal plane for IMAC must be used in IAC, not in any other competition.

But again, I am not sure to understang you on this one
Old 03-09-2004, 10:52 AM
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Default RE: 10% rule is coming back, what the heck? Info please!

The plane was ALSO flown at the Henry Haigh Challange last year in Primary class - second place finish
This is an IAC event - look it up.
A bit confusing -I admit
Old 03-09-2004, 10:56 AM
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Default RE: 10% rule is coming back, what the heck? Info please!

Thanks Tom,

Actually the Extra I have has a 92" Span. But I believe it's 90" long. I'll have to quickly crunch the numbers.

Mr. Hanson, interesting stuff! Can you actually use a Cassut in IMAC?

Wierd question...was Art Scholl's Super Chipmunk ever flown in IAC? Not that I am building one, I just wonder if THAT plane would be IMAC legal....hmmmm

Thanks for the interesting conversation.
Dave
Old 03-09-2004, 11:01 AM
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Default RE: 10% rule is coming back, what the heck? Info please!

Tom,
Looks like I'm in there! Thanks, hopefully we'll see you in the Southwest this year!
Old 03-09-2004, 11:06 AM
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Default RE: 10% rule is coming back, what the heck? Info please!

Flown in anIAC event- Ithought that was a criteria -but I know of several models used routinely in IMAC-which never met that criteria.
BUT-- some were flown in other aerobatic events and some were simply scale -
Does anyone actually have a guideline for which -if any full scale competitions are considered a desireable/legal basis for the plane used?
Old 03-09-2004, 11:58 AM
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Tom Wheeler
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Default RE: 10% rule is coming back, what the heck? Info please!

Here is the official rule:

3.1. The events accommodate aerobatic monoplanes and biplanes which are replicas of types known to have competed in International Aerobatic Club (IAC) competition, or replicas of types known to be capable of aerobatic competition within the airspace known as the “Box.”

At one time ( prior to 2000 ) the aircraft in question did indeed have to have flown in an IAC event in order for it to be legal in IMAC. That rule change back in 2000 I think, to include aircraft that are known to be capable of aerobatic competition within a box. One of the main drivers of this rule change back then was to include then new aircraft like the Edge 540T that were made available as a scale model before the full scale prototype flew in competition. Also it becomes a real pain in the neck to know all of the aircraft type that have flown in IAC competitions.

Tom Wheeler
IMAC President
Old 03-09-2004, 01:27 PM
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Default RE: 10% rule is coming back, what the heck? Info please!

Thanks for nice the clarification-I know that a fair bit of speculation keeps cropping up.
My Dalotel -which is SCALE - never entered any full scale competition -but was designed/flown and hawked as an aerobatic plane .
That is an example of "capable of"-
The Cassut-on the other hand looks like it can't fly aerobatics very well but it DID enter and placed in IAC last year
That is of course ,the primary qualification.
W Matt has a new bird that looks like a pattern plane -
The full scale, was built for competition -but as far as I know ,never has competed in full scale .
That fits in how the Edge540T was accepted.
In my book all of this is good -
more diversification and still all in keping with the primary intent of IMAC
Guess I better send in my lapsed renewal---
Sorry about that ---
Old 03-10-2004, 05:45 PM
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Default RE: 10% rule is coming back, what the heck? Info please!

Tom,

You missed the scale by one generation. The 300 is 26.25 ft or 315 inches. A 300L is 25.25ft or 303 inches wingspan. 31% of that is about 94". A 300L is 274 inches long so 31% would be 85 inches thus a scale 31% 300L would span 94" and length 85", 10% of 85 is 8.5 giving you up to 93.5 inches in length to be legal. I looked on the CA website. Their plane is 93" span and 88" long... Well within the rules. Now we can all stop worrying

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