Classic vs. Modern: A tale of short coupled ....

OK guys,
Expert (and non) opinions/knowledge wanted here.
Explain how a "Classic" ship like the Ares/Argus type plane with a shorter tail moment and small stab/elev set up can fly so well when the *new* designs have 1/2A wings for stabs and 18+ tail moments?
Is it a power thing? What else is going on? I have seen some really great flights from the older planes that seem to defy the current trends.
This especially struck home when I was flying my Geo Juno (*new* design) and my USA-1 along with Aaron's Ares. Seems to be very similar flight characteristics. Now, I am not an *expert* caliber flier, but do compete in Advanced ok, and have flown quite a number of different stunt planes.
What gives?
TIA
Bill

Hi Bill,

Just an opinion from a barely expert. The answer is, there probably isn't much improvement in flight characteristics other than personal taste. I've built classic planes that are short coupled as you note and the have flown quite well, generally. Mine have tended to be a little rough in level flight and had a tendency to be harder to fly in serious wind, but that could and probably is just me.

The idea with longer tail moments is to increase the smoothness and tracking. The big stab is (at least for me) more a need to abruptly stop a turn that anything else. The planes I've built with very long tail moments and very big tailplanes have tended to have a killer turn and very predictable flight characteristics. But then, I also snapped the fuselage in heavy wind at Portland this year on just such a plane, so there are some drawbacks.

Bill,

I think it has to do more with the modern powerplants in the older designs than anything else. I have an Intrepid X/L with a piped PA .51 and a Shark .45 (1961 version) with an ST .51. They both fly very very similarly. In fact my highest scoring flight is with the Shark. So I think that the power plant is the REAL determing factor in A/C performance. Of course you can build a dud with anyone's desing if you don't build carefully.

Ok, Where's the rest of the opinions?????
TIA
Bill

Great question!
This is something that I have thought quite a bit about. My feeling is that the guys way back yonder really knew what they were doing much more than we realize. What is important to remember, is that the pattern we do now is identical to the pattern decades earlier. The requirements we face today is essentially identical to the requirements they had to contend with. I happen to personallly know Tim Meeks who was intrumental in developing the Cobra stunt ship with the late Steve Wooley. Tim knows what he is doing! Bart Klapinsky, who developed the Tempest stunt ship and won the 1967 United States Nationals, can probably assess the flight characteristics of a stunt ship faster than just about anyone. We still have to fly at approximately the same speed so that the judges can see what we are doing, and we still have to deal with the same contraints of starting and stopping relatively violent maneuvers in a confined hemisphere. According to Bob Hunt, the primary difference between then and now is that the advent of better powerplants has greatly extended the competive careers of stunt flyers. The demands of putting earlier, relatively underpowered planes through precise manuevers put a strain on skills and reflexes such that, flyers had to "retire" relatively early. Now, flyers like Bill Werwage and Ted Fancher and Bob Hunt can remain competitive fairly late into their careers. It is much easier for me to put my Saito 72 Backfire through it's paces then when I flew my Fox 35 powered Magician. In certain respects, the Magician may be every bit as good as a Backfire, but the Fox cannot hold a candle to a Saito 72. It is my opinion that, the planes just evolved to maintain parity with the new powerplants.

>OK guys,
>Expert (and non) opinions/knowledge wanted here.
>Explain how a "Classic" ship like the Ares/Argus type plane
>with a shorter tail moment and small stab/elev set up can
>fly so well when the *new* designs have 1/2A wings for stabs
>and 18+ tail moments?
>Is it a power thing? What else is going on? I have seen
>some really great flights from the older planes that seem to
>defy the current trends.

This is the sort of question that starts arguments, and I am sick of arguing. So I won't really go into it.

But. at least one thing to remember is that *design* , no matter how much we like talking about it. is a very, very, tiny fraction of the various elements that go into making a good-flying system. Power, trim, control geometry, and on and on, are all such large factors that the typical "scatter" in these other factors is far larger than the difference between a 14.5" and a 17" tail moment. In other words, everything else has to be darn near perfect before you can even begin to tell the difference.

I might also add that you picked modern airplanes that were as close as you could get to a continuous evolution with the older ones- having all been designed by Billy, who has been slightly evolving everything over a very long period, but with the same basic precepts all along. As opposed to something that's really very different with a different set of ideas - say, an Impact or a Trivial Pursuit.

I got something to say. I never seen or flew a CLASSIC plane until I joined the Control line club here in Portland.
The Question Differences between Classic and Modern? NOTING. The planes are, will, and always are designed from the OLD TIME PLANES. EVELUTION is the difference. NO brainer. With old time planes we (the flyer) had to work with what we had. Classic had new types of engines and fuel. Modern has Engines and Fuel and construction methods and builders with the knowledge from the makers of the first generation of flyers. So what’s my point? The “NOBLER” MOST of the planes out there that fly worth a damm have Nobler Numbers. If George had not made the NOBLER WORK I don’t know what would of happened. REMEMBER, Stunt is just a small part of control line flying. There are many other planes out there that fly well. HOWEVER, most are designed in the 50’s or early 60’s…Ringmaster, All American, Go-Devil, Wild Man, Smoothie, Firecat, Shark, Sky Dancer, Mars, and T-Bird. There are many others. But what makes Modern so neat is the designers are still here. Paul, Ted & David, Windy, Big JIM, and now Brad and Steve. Really, Nothings Changed…just time.

Scott (just happy to be here) Riese

Could ease of trimming have anything to do with it? One problem with the old short-coupled Combat designs (e.g. Warlord) was that the CG had to be spot on, within 1/8", I've been told. Extend the tail moment and use a bigger tail, and you have a much broader range of acceptable CG locations. Stunt trimming is a lot more finicky than Combat trimming, so perhaps the not-so-large difference between Classic and Modern designs might still be due to relative ease in trimming the modern ones.

>Could ease of trimming have anything to do with it? One
>problem with the old short-coupled Combat designs (e.g.
>Warlord) was that the CG had to be spot on, within 1/8",
>I've been told. Extend the tail moment and use a bigger
>tail, and you have a much broader range of acceptable CG
>locations. Stunt trimming is a lot more finicky than Combat
>trimming, so perhaps the not-so-large difference between
>Classic and Modern designs might still be due to relative
>ease in trimming the modern ones.

ISKY,

BINGO!

Ted, Isky

I think the modern planes can be trimmed more accurately than in days of old but easier? I don't think so. Think about it. There are at least eight things on modern planes used for trimming purposes.
Leadouts, Wing Tip weight, Rudder offset, Wing trim tabs, Tail weight, Nose weight sometimes, then all the engine stuff like props, pitches, head gaskets, venturi's and so forth. That's a lot more adjustments than were used in days of old when we tweaked the flaps and put a little more tip weight in when necessary or maby a different prop. I'm still in the process of getting my Intrepid trimmed and it's only been 4 years of working on it. In fact, I find that trim setups for one set of conditions don't work in other conditions and on and on -----Whew!

>Ted, Isky
>
>I think the modern planes can be trimmed more accurately
>than in days of old but easier? I don't think so. Think
>about it. There are at least eight things on modern planes
>used for trimming purposes.
>Leadouts, Wing Tip weight, Rudder offset, Wing trim tabs,
>Tail weight, Nose weight sometimes, then all the engine
>stuff like props, pitches, head gaskets, venturi's and so
>forth. That's a lot more adjustments than were used in days
>of old when we tweaked the flaps and put a little more tip
>weight in when necessary or maby a different prop. I'm
>still in the process of getting my Intrepid trimmed and it's
>only been 4 years of working on it. In fact, I find that
>trim setups for one set of conditions don't work in other
>conditions and on and on -----Whew!
>
>
>Jim Pollock

POINT REASONABLY WELL TAKEN, JIM.

LET'S JUST SAY THAT YOU "CAN" TRIM THE MODERN SHIPS!

GO BACK AND REREAD MOST OF THE PRE MID '70S OR SO CONSTRUCTION ARTICLES AND THE TOTAL DISCUSSION OF "FLIGHT TRIM" PRETTY MUCH CONSISTED OF "... IF THE AIRPLANE IS TOO SENSITIVE ADD WEIGHT TO THE NOSE AND IF IT IS TOO SLOW TO RESPOND ADD WEIGHT TO THE TAIL".

>POINT REASONABLY WELL TAKEN, JIM.

>LET'S JUST SAY THAT YOU <"CAN"> TRIM THE MODERN SHIPS!

>TED

ABSOLUTELY!

Jim Pollock

I would agree that this is the real point. You can trim the new designs and with the old designs you just "lived" with it. If you can trim them, and trim them more accurately, then the new designs are going to fly better because of the more accurate trim. And if they have a greater range of trim, it does make it easier both to trim and to fly.

However, perhaps if you did build in all the adjustable things into an older design so you could trim it to modern standards, you'd find it harder to trim than the modern design.

"However, perhaps if you did build in all the adjustable things into an older design so you could trim it to modern standards, you'd find it harder to trim than the modern design. "

Isky, can you please elaborate? I've just completed a Brodak Smoothie, which is a design from the early 50's, and it has a tip weight box and adjustable leadouts. I'm using a Fox 35 for power. As far as I can tell, aside from the leadout guide and tip weight box, it's exactly like the Smoothie that Bob Palmer flew (aside from my obvious lack of building skill). Why would it be harder to trim than a modern design? Is it inherently less stable? Or is it because it's comparatively underpowered? I'm not being argumentative, I am interested in the answers to these questions, because I like to learn about this stuff...

>>Ted, Isky
>>
>>I think the modern planes can be trimmed more accurately
>>than in days of old but easier? I don't think so. Think
>>about it. There are at least eight things on modern planes
>>used for trimming purposes.
>>Leadouts, Wing Tip weight, Rudder offset, Wing trim tabs,
>>Tail weight, Nose weight sometimes, then all the engine
>>stuff like props, pitches, head gaskets, venturi's and so
>>forth. That's a lot more adjustments than were used in days
>>of old when we tweaked the flaps and put a little more tip
>>weight in when necessary or maby a different prop. I'm
>>still in the process of getting my Intrepid trimmed and it's
>>only been 4 years of working on it. In fact, I find that
>>trim setups for one set of conditions don't work in other
>>conditions and on and on -----Whew!
>>
>>
>>Jim Pollock
>
>POINT REASONABLY WELL TAKEN, JIM.
>
>LET'S JUST SAY THAT YOU "CAN" TRIM THE MODERN SHIPS!
>
>GO BACK AND REREAD MOST OF THE PRE MID '70S OR SO
>CONSTRUCTION ARTICLES AND THE TOTAL DISCUSSION OF "FLIGHT
>TRIM" PRETTY MUCH CONSISTED OF "... IF THE AIRPLANE IS TOO
>SENSITIVE ADD WEIGHT TO THE NOSE AND IF IT IS TOO SLOW TO
>RESPOND ADD WEIGHT TO THE TAIL".
>
>
>
>TED

you at a NASA Macintosh, Ted?

You were fasterthan me, but tht's it!

You CAN trim new design, and it (sorry Brett) doesn't take that much perfection to notice it.

I got a local design of a small stunter and gave it some more tail and Stab/elevator surface, and wow!

It became a LOT more *trimmable*...

God bless you!

In Christ,

I think Brett is exactly right. It has a lot more to do with the overall package, not just a particular element of a design. I think Billy Werwage once said that the design is important, then there's the other 3/4 of a good flying plane...the powertain.

I certainly think that the biggest advances have been in engines, props and fuel delivery systems. Much more so than airframe design. When I build a plane, or design one, I'm certainly trying to get to something; some idea or another. But I will say it's amazing how many less than sterling design ideas I've been able to overcome (at least to some extent) by a great running powertrain.

It seems to me that how moments are measured is more the concern here when you think about it. A Nobler has ten inch root as does a Geobolt wing. Where the CG and high point of the airfoil is in conjuction with these moments about the CG and the MAC has much to do with performance.

For example a forward CG Nobler has a longer tail moment than a simple measured 14.5 inches from TE to TE or whatever and a Geobolt wing with an aft CG and larger tail surfaces are not miles off in moments if you consider the nose moment is only as long as required to fit in a motor and fuel tank in most cases and the tail moment only long enough to get the airplane to balance at a desired point for a particular airfoil. Old birds arent as short coupled as you might think but the cord of most old birds is a tad wider for the span and thinner than a most modern planes.

>>OK guys,
>>Expert (and non) opinions/knowledge wanted here.
>>Explain how a "Classic" ship like the Ares/Argus type plane
>>with a shorter tail moment and small stab/elev set up can
>>fly so well when the *new* designs have 1/2A wings for stabs
>>and 18+ tail moments?
>>Is it a power thing? What else is going on? I have seen
>>some really great flights from the older planes that seem to
>>defy the current trends.

> This is the sort of question that starts arguments, and I
>am sick of arguing. So I won't really go into it.

Hi Brett, The *argument* was/is not my intention.

> But. at least one thing to remember is that *design* , no
>matter how much we like talking about it. is a very, very,
>tiny fraction of the various elements that go into making a
>good-flying system. Power, trim, control geometry, and on
>and on, are all such large factors that the typical
>"scatter" in these other factors is far larger than the
>difference between a 14.5" and a 17" tail moment. In other
>words, everything else has to be darn near perfect before
>you can even begin to tell the difference.

ok. I can understand that.

> I might also add that you picked modern airplanes that
>were as close as you could get to a continuous evolution
>with the older ones- having all been designed by Billy, who
>has been slightly evolving everything over a very long
>period, but with the same basic precepts all along. As
>opposed to something that's really very different with a
>different set of ideas - say, an Impact or a Trivial
>Pursuit.

>Brett

Well, the USA-1 and Ares are Billy's, but the Geo Juno is based on the Saturn. However I didn't consider your point when I was asking the question. I guess the *evolution* segment is a great big point to consider.
However, I have used a SV-11 (ST 51) and a '92 Cardinal (OS46VF-pipe)
And saw the aspects I am asking about.
Thanks for your input!
Bill

All I have to add:
WOW, what a great "discussion"--KEEP it up. You fellows really hit your stride. Better than BOM or AMA or not AMA Thanks-R3C-2 Dave S

I have seen Marvin Dinny flying an "All American"with a Fox 35 (of course),and Jim Lee flying a "Hummingbird" powered by a OS FP15, and both of those planes were short coupled. I believe Jim won Expert with his one year at our Tulsa contest, and Marvin usually places high also.
Both of those airplanes cut a corner tighter than a modern stunt ship.
The only disadvantage I could see was they both are twitchey and fly like a combat ship. They are both excellent pilots and have lots of handle time, which I am sure makes a substantial difference.

Or an "Infinity"...

God bless you Brett!

In Christ,

I'll have my two cents worth here too.

If you took the 50 best flyers, put them in the one contest, then at the end of Round 1 you would have a top-ten list. THEN, for the second round, each flyer has to fly another competitor's model. Oh My! I guarantee that the Round 2 top-ten would include at least 7 of the Round 1 top-ten !!!!

All the airplane can do by itself is sit on the ground and look pretty. The PILOT wins a competition! Why? - the winner has the best attitude - the nerves, the concentration, and obviously the ability where reflexes, timing, eyesight, and judgement are concerned.

A good attitude can win with an average airplane, but a poor attitude will never win even with the very "best" airplane, if there is such a thing.

Where individual designs are concerned - consider, for example, that there are 1000 different design elements. We stick our arm into the barrel and pull out a package of 20 or so that we think/hope will work. Not one single element will ever make a huge difference. It's how that element works in conjunction with the other 19 that makes either a flyable airplane or a high-powered truck. When you look closely at the requirements for a true 45 degree pattern, what is needed is a sprightly sports car rather than a big Mack.

When Bob Palmer was in Sydney Aust in 2000, he commented that "the models of today don't suit the pattern, so change either the model or the pattern". I believe there's a lot of truth in that statement.