Kindly define a “heavy” airplane.

[frank mccune]

     Hello All:

     I have been told that my planes are too heavy.  I am seeking a definition for too heavy.  It must be defined by the weight/number of square inches of wing area.  If so, what are some wing loading numbers that would indicate a light stunt airplane?

     Tia,

     Frank McCune

[Dwayne Donnelly]

If when you pull up into a wing over and the plane falls into the circle it's to heavy, ask me how I know. 

[Mike Alimov]

     Hello All:

     I have been told that my planes are too heavy.  I am seeking a definition for too heavy.  It must be defined by the weight/number of square inches of wing area.  If so, what are some wing loading numbers that would indicate a light stunt airplane?

     Tia,

     Frank McCune

Below 10 oz/sq.ft is too light; 12-13 is good; 14 is marginal; 15 and above is heavy. Notice, "heavy" doesn't mean totally unflyable, but the plane will demand extra power, and sharp cornering may lead to near stall conditions in low density air.
Just my opinion.

[Paul Walker]

Depends on power system. They are different.

My electrics work at about 13 oz/ft^2 with battery.

[GERALD WIMMER]

Hello I have a spreadsheet and record all our families models details including the wing-loading with a current range of a nice light 9.67 oz/sq-ft for my wife's Veco Chief to a very heavy 17.8 for my youngest son Max's stunt trainer (only good for big round loops and practicing takeoff and landings!).
Most models fly well up to 14-15oz/sq-ft if trimmed well and with plenty of power and often better then light models that have too much flex in surfaces or controls.
I update the spreadsheet as they all put on weight after crash repairs and with fuel soakage and it is common for a new model in the 12-13 range  to go up to the 14-15's with a hard life after a decade or so. Electric models normally stay lighter, need less refinishing and are easier to repair with out oil ingress.

Regards Gerald

[Paul Smith]

An airplane must be as light as possible but not much lighter.

[Ken Culbertson]

My target weight is 13 oz ft^2 in hopes of keeping it under 14.  With the power we have today 14 is not heavy.  Back in the 60's it was 11.  How things have changed.

Ken

[Gerald Arana]

An airplane must be as light as possible but not much lighter.

I disagree! See Ted Fancher's article on his "Tucker". Personally. I find "light' ships don't fly well in the wind.....but then again, I fly advanced.

Being an old glider flyer, lead is a good thing in the wind.

erry

[Paul Smith]

A lighter airplane can fly slower and turn tighter, which seem to be the accepted path to higher scores.  But then a plane falls apart gets no points at all.

[Ted Fancher]

I give up!

[John Park]

It varies with wing area - small models need a lower wing loading than bigger ones.

[Gary Dowler]

Wow, the Cobra I’m presently flying is 9.44oz per sq ft. 

Gary

[Dick Pacini]

What are these ounces you speak of?  I always measured mine in pounds. 

[Mike Griffin]

What Ted said.

Mike

[Ted Fancher]

I give up!

Everyone should seal their inflatable newly available sealed "Stunt Skins" and fill 'em with helium until they float and, ta da!, Nirvana and perfect patterns are at last the norm...winners determined solely by contributions to the judging staff.  And the really good news goes on as that once the ships weigh less than the air they displace there will be zero line tension and, thus, no more sore arms the day after the WCs are over!  Oh, yeah.  And because they float you won't need that pesky wingy thing anymore and the expense for the helium will be cut way down. oh...and shoot...you'll be able to fly the whole pattern on  a couple of rechargeable double AAs!  (I know, I know!  That last was a joke; even zero ounce stunters have drag.  Hmmm. Let me get back to you on that one.

Ted

p.s. This, I hope, is recognized as a joke...albeit a joke with intended underlying thought provocations.  I wish somebody had kept track of the weight of the last 50 or so Nats winners...say from the end of the Fox .35, 5.5second lap era.

p.p.s.  You're forgiven Bubba!  OH, and p.p.p.s.  Why was it you felt it advisable to utilize flaps (high/increased, lift devices) on those feather weight ships?  Wouldn't their adverse pitching moment restrict the ability for tighter corners?  Were you afraid the ships would stall without them?  I'm a little embarrassed that I don't recall ever knowing the weight of a new ship (except the low thirty or so oz Tucker addressed regularly on SH) until taking it to their first significant contest where they were weighed during check-in.

Oh and--what the heck-- if you were able to build a 20oz Super Stunter of modern dimensions would you be inclined to do so??  Is there a "any" point at which you would say it's too light?!

Luv ya, Bubba!

[frank mccune]

      Thanks for all of the replies!

       Stay cool,

       Frank

[Ted Fancher]

Ah, Hang in there, Frank.  It's just starting to get good. 

Bubba (Bob Hunt) and I have been best buds for, quite literally, decades.  Two of my favorite things about us were:

1. When we sat in his car for a couple of hours late at night in front of my hotel in down town New York talking stunt and the world in general and;

2. When upon first meeting Bob when I was attending a decades ago first "modern" Nats for us with Bill Fitzgerald (David Fitz's late/great Dad).  Somehow, Bill and I and probably David were invited to Bob's hotel room to check out his stunt "stuff".  I will never forget Bill getting down on his knees at Bob's bed and picking up his competition ship (I don't now recall the ship's name but Bob will!) with a hand under each wing...turning his head to face me wide eyed...and declaring in obvious awe; "Ted, it don't weigh nothin!"

See, Frank.  Bubba was wrong decades ago! 

[Brett Buck]

I have been told that my planes are too heavy.

     From some perspectives that might be true, but given what I know about your situation, I doubt that any of them are heavy enough to make any significant difference. It is very rare indeed to find a stunt airplane that won't fly simply because it is too heavy, and I assure you that there are *many* lead sled models out there that are almost certainly heavier than yours.

   Usually, there are other issues along with heavy, and these other issues are typically fixable. Get the engine to run properly, get the trim and alignment correct, fix the control system to be free and sufficiently sturdy, and it will be plenty good enough for sport flying.

    Most of the arguments about weight are both demonstrably wrong, and/or applicable only to guys like Ted/Bob/Paul who are comparing details that only relevant to high-end competition. Unfortunately, this can lead people to weigh their airplanes and just give up without even trying to fix all the other issues.

    Brett

[Dick Pacini]

Back in the 60's when hobby shops had stacks of kits, Jack Sheeks told me to bring a baby scale when buying a kit.  Buying a Nobler, three kits on the shelf?  Buy the lightest one.

[PJ Rowland]

As far as Classic planes is concerned.

I broke the status quo by putting .61's into them. In a nice locked in deep 4 cycle on a 7" pitch prop 5.8 sec laps . Drive is amazing.. control is equally impressive.

When you have THAT sort of power to weight ratio my 54 oz Gieseke Nobler made Top 20.

It is what it is..

When you have Multiple people say weight isnt the issue of a modern plane, its because lightweight planes just DONT fly as well as 'folklore" claim.

Teds Tucker special, you could put a .75 in it and it would fly well.. heck I shoehorned an .81 into an ares just to fly it..

What you realise is once you have "sufficient" power to climb and regulate the speed, the only requirement of the wing is to maintain lift during the turn. 
And even IF the airflow rolls off the power makes up for it in bucket loads.

Why do you think the average wing area in the last 30 years has stayed the same but motors have gone UP.. thats where we went from 50 oz to 60 oz to 70oz its just power.

Not to mention airflow devices employed on most Top stunt ships.

[GERALD WIMMER]

As far as Classic planes is concerned.

Teds Tucker special, you could put a .75 in it and it would fly well.. heck I shoehorned an .81 into an ares just to fly it..

Hello More Power always the answer!
 Interesting when you get two F2D style combat wings and set one up  light with .15 and the other with a tuned pipe .36 with a long boom and bigger elevator it will turn tight and fly much faster.  The .15 enginened model feels nice and nippy but the .36 is exciting and pulls like crazy, but perhaps too much!

Regards Gerald

[Chris Wilson]

     Hello All:

     I have been told that my planes are too heavy.  I am seeking a definition for too heavy.  It must be defined by the weight/number of square inches of wing area.  If so, what are some wing loading numbers that would indicate a light stunt airplane?

     Tia,

     Frank McCune

Ask the person who told you for an answer.
Frank, don't take this the wrong way but over the years that I have been reading your posts you tend to ask extremely open ended questions that will similarly attract many and varied open answers.
This leads to infighting amongst those in the know and makes me wonder, is this intended?
Chris.

[peabody]

As I understand it, Bob Baron was US National Champion with a Patternmaster / ST 60 combo that was REALLY heavy for a plane that size....well over 70 oz.
Talent play in here too.

BUT, for the average builder/flyer Bob Hunt's suggestions (light, straight and properly powered being the three primary factor) are spot on.

Have fun.

[frank mccune]

     Hello Chris Wilson:

     If my questions appear to be open ended, it may have been influenced by my 33 years of being in the classroom. There is no dark reason behind the way that I present my questions.  I have learned that asking questions is superior to being ignorant.

     I continue to ask questions like, “Does  conscienceness (sp) exist throughout the multiverse or how does one get closer to a horizon?


     One of the people with whom I fly toy airplanes is a psychiatrist so I must be very careful as th what I say! Lol
     
      Do not be bound by reality.

       Stay well,

       Frank McCune

[John Lindberg]

A heavy airplane can be defined by anything I build!

[frank mccune]

     Hello Air Master:

      It is a a funny thing that you mentioned going to longer lines.  The last time that I flew my Magician, I went from 60’ lines to 55’ lines.  What a great improvement! The Magician flew perfectly. 

       The set up for Magician was OS .35S, 10-6 prop, 25% castor oil and 5% nitro.  I know that this is old school thinking, but the plane has been hanging in my attic for the last three decades waiting to be used so, why not? Lol. The engine performs like a dream and all is good.  A fun time was had by all. Lol

        Perhaps lines being too long was the cause of the loss of my last four stunt planes.  I was losing line tension up high resulting in the loss of the plane.  Of course, I can make my planes fly with more speed, but this action is for another time.  Let us match lap times with both lengths of lines before making more assumptions.  This may lead to more fun. Lol

      Stay cool,

      Frank

[Brett Buck]

This topic must be why people who advertise "expertly built" planes won't say how much they weigh.

   At the NATs, every airplane is weighed and you can look at the pull test values on the pit boss sheet and see how much they weigh within a few ounces. There are no real secrets among the actual players.

     For the record, at the NATs on the NATs scale, mine weighed 64.6 ounces. At home on my own scale, I get 62.4. The difference is irrelevant.

    Ted got frustrated with this topic, and I do too, because people are obsessed with the topic to the point that they simply give up if the scale says more than they wanted. It's like it gives everyone an excuse to not bother trimming or adjusting the engine. I absolutely, positively, guarantee that given two perfectly trimmed airplanes, one weighing 56 ounces, and another weighing 66 ounces, almost *no one here* would be able to tell the difference, and even the heavy one would be the greatest airplane they ever flew.

  Yes, they can be too heavy. They can also be too light. But for almost everyone, it won't make the slightest difference, because regardless of weight, the airplanes will be in terrible trim and have less-than-ideal engine setup. That is where everyone should be focusing, and it would do everyone a great deal of good to throw out their scales so they wouldn't even *know* what it weighs.

    Brett

[Ted Fancher]

"snip"
   
    Ted got frustrated with this topic, and I do too, because people are obsessed with the topic to the point that they simply give up if the scale says more than they wanted. It's like it gives everyone an excuse to not bother trimming or adjusting the engine. I absolutely, positively, guarantee that given two perfectly trimmed airplanes, one weighing 56 ounces, and another weighing 66 ounces, almost *no one here* would be able to tell the difference, and even the heavy one would be the greatest airplane they ever flew.

  Yes, they can be too heavy. They can also be too light. But for almost everyone, it won't make the slightest difference, because regardless of weight, the airplanes will be in terrible trim and have less-than-ideal engine setup. That is where everyone should be focusing, and it would do everyone a great deal of good to throw out their scales so they wouldn't even *know* what it weighs.

"snip"

Naw, Brett.  I actually get a kick out of the never ending debate...although I do agree with you about throwing out the shop scales!  I have one that measures in fractions of grams that I've kept atop the large cabinet over my (generally unoccupied of late) work bench for decades but, alas, due to my always modest and forever shrinking human ceiling, was almost never utilized as it required finding a stool or ladder to access.  I am, nonetheless, looking forward to Bob's answer with respect to the flapped, zero ounce nirvana stunt ship still somewhere over the horizon!  They can, after all, "never" be too light!

p.s. Watching that short video of this year's Walker Flyoff in the gale I couldn't help but harken back to the era of 40 ounce Noblers,etc. balanced at the then more or less standard 15% MAC of the era and wonder how many of the three predictably ever expanding consecutive loops would have been completed before impact despite 100% max control deflection as a result of being hung on the up/down line as each loop got bigger and bigger!

Ted

[Leonard Bourel]

I agree Toss the scale and get the plane trimmed the best you can and get the best motor and motor run you can I bet you will be happy . My Rojett 90 powered Tank is a real hand full at 88ozs but every now and again I pull it out for a few flights because I get an idea how to make it fly just a little bit better . I have moved on to lighter and better projects but even the heavy weights can be made better.

[Ken Culbertson]

oh, and p.s.: although, as you suggest, the actual gross weight seldom is a game killer issue...where the weight is concentrated (fore/aft CG location) can very well be.

Thank you for injecting or reinjecting that truth into the discussion.  It is like being 180 lbs with a beer belly(in my case it was potato chips) is fat where 220 and in shape is not. 

Ken

[Chris Wilson]

     Hello Chris Wilson:

     If my questions appear to be open ended, it may have been influenced by my 33 years of being in the classroom. There is no dark reason behind the way that I present my questions.  I have learned that asking questions is superior to being ignorant.

     I continue to ask questions like, “Does  conscienceness (sp) exist throughout the multiverse or how does one get closer to a horizon?


     One of the people with whom I fly toy airplanes is a psychiatrist so I must be very careful as th what I say! Lol
     
      Do not be bound by reality.

       Stay well,

       Frank McCune

Thanks Frank,
So I gather there is no real question that needs to be answered but rather it's more " Open your textbooks to page 25 and discuss."
Not a fan of that technique in an open forum.

[Craig Beswick]

I think it is a relevant question and topic. Regardless of how it is asked.

When you have people of the ilk of Brett Buck, Ted Fancher and Paul Walker, along with notable others, chiming in with information, that would suggest to me a reasonably successful topic?

As a novice there is an enormous amount of information on the forum and sometimes it is difficult to see the forest for the trees.

I was astounded at the recent Nats weights! The top guys all seemed to be around 64oz +/- 2oz. I thought that was on the heavy side but clearly not.

Having watched enough of Roberts videos I was of the opinion that lighter is always better and under 60oz was the goal. Perhaps yes perhaps no. But probably not critical for someone in my situation.

Reading all this helps when my plane weight blows out. Sure, if I ever get good enough, it will become a lot more critical, but, as another poster mentioned, I'm not going to just hang up a plane because it ends up being 4 to 6 oz over weight.

So, Frank, keep asking your questions buddy. This thread has been enormously helpful to me and I thank you for it.

Craig Beswick

[PJ Rowland]

Brett is spot on. The trim of the plane has always been the single most important factor you CAN control.

This question would be much better asked if we replaced the word weight with trim..

Hello All:

     I have been told that my planes are not in trim.  I am seeking a definition for "in trim".  It must be defined by the factors that constitute trim..  If so, what are some trim loading numbers that would indicate a well trimmed stunt airplane?


See my point ?

[Matt Colan]

I have two airplanes, both very similar in design, same wing/tail/power plant, but with a different fuselage shape. The first one weighs 59 ounces, and the second one weighed 69 ounces at this years NATS. The heavier airplane flies better than the light one, but not due to weight. Near as I can tell, I can’t tell a bit of difference over the weight being a direct correlation to the performance of the airplane. The heavier plane flies better due to me learning how important linear, and butter smooth controls are thanks to Brett and Dave Fitzgerald.

I am in full agreement with Brett that proper trim and proper power are going to determine the final performance of the airplane. Don’t build a brick but weight isn’t going to determine everything when it comes to airplane performance

[Chris Wilson]

I agree, an ideal is always a range.
What has been quoted by Brett, Ted and Paul probably relates to their own high end F2B models.
What models is the author relating too?
An acceptable wing loading can be dependent on Reynolds numbers, can my Cox 049 20" span model carry the same loading as a Discovery 60 powered Yatesenko?
It can be dependent on air foil effeciency, does my flat plate stunt trainer carry as much wing loading as my Peacemaker?
The wind conditions, adding weight helps with penetration.
Altitude, adding wing area regains lost lift in thin air.
Configuration, take the common tractor monoplane with one lifting surface, spin it around into a canard that now recognises two lifting surfaces, can it now carry more weight because a formula tells you so?
I suppose my answer to when is a model too light is when that lack of mass gives unpredictable control and adding it regains it.
Classic case is tip weight, it depends.
Chris.

[Doug Moon]

I have been building and flying basically the same plane for 20 years. The lightest one was the first one I had in 2002.  It was 59oz I think right off the board.  I also build that one in 12 weeks from start to initial flight. Or something like that. It was fast for me and the plane turned out to be a great model I flew for may years. From there the planes got progressively heavier. The last one was 72 oz with a 75.  I feel that was the too heavy. How do I know?  With proper trim and good solid speed for consistent maneuvers in hot conditions like we normally fly in the plane would "slide" into the intersections and "slide" through corners.  It was way way worse in high humidity conditions. After exhausting many different avenues with this model I retired it.  Interestingly enough the plane that brought me my most success weighed 66oz. I was told the wing I use "will never fly" if it is above 63oz.  "It wont carry the weight" they said. It did really well.  In the end it really is about trimming to your personal preference and making the plane work for what will work for that model.  If what will work for that model wont work for you then you have to make decision...

[Mike Griffin]

It was like chasing the 18 ounce Ringmaster.  Maybe Dee Rice built one, my memory fails me, but I know some wings folded.  Bob beat me to it, you can fly a brick if you put a big enough engine on it.  There was a thread not to long ago on here somewhere about boring lighting holes on profiles and if that should be done and if it made any difference in performance. 

When did being lighter than air become such and obsession in building toy planes?  Some people are just too damn anal about it.

Listen to Brett and Ted.  Trim the model correctly and worry less about what doesnt matter all that much.

Mike

[Ken Culbertson]

It was like chasing the 18 ounce Ringmaster.  Maybe Dee Rice built one, my memory fails me, but I know some wings folded.  Bob beat me to it, you can fly a brick if you put a big enough engine on it.  There was a thread not to long ago on here somewhere about boring lighting holes on profiles and if that should be done and if it made any difference in performance. 

When did being lighter than air become such and obsession in building toy planes?  Some people are just too damn anal about it.

Listen to Brett and Ted.  Trim the model correctly and worry less about what doesnt matter all that much.

Mike

Miss Piggy would be proud! 
Anybody that has ever built a Sterling kit knows that heavy airplanes can fly quite well.
Ken

[Mike Griffin]

Good point Ken.

Mike

[944_Jim]

If when you pull up into a wing over and the plane falls into the circle it's to heavy, ask me how I know. 

As a fledgling pilot I know what too heavy looks like...pancaking out of the bottom third of a loop that started well behaved! Wingovers were good enough. However,  I trashed an attractive 1/2A model because it just couldn't create enough lift. It did rotate to level, but just kept dropping like a rock on the backside. Too much engine, too much solder on the tailskid! I do plan on attacking a reproduction of that kit, but with a smaller, lighter engine and construction!

[M Spencer]

A heavy aeroplane is one that wont get off the ground .

Bought a completed scale Fairy Gannet , trike gear in 70s .
It flew / out a tank with one lap airborne & a 30 foot hop to two feet ( maybe ? ) a few laps later . Mustve been 50 laps plus . Either it was to heavy or to underpowered . 



You can see how he's aged , and dosnt look to happy . After He's tried to fly it . 

[Shorts,David]

I have some experience in too heavy.

1. When a plane is too heavy, it stalls in corners, especially the 4th corner of the inside square, or 2nd corner of outside, bottom corner of hourglass and triangle, when gravity is working against your obese aircraft. If it doesn't stall in the 4th corner, it is not too heavy, assuming you have sufficient power.

[Ted Fancher]

I have some experience in too heavy.

1. When a plane is too heavy, it stalls in corners, especially the 4th corner of the inside square, or 2nd corner of outside, bottom corner of hourglass and triangle, when gravity is working against your obese aircraft. If it doesn't stall in the 4th corner, it is not too heavy, assuming you have sufficient power.

Wrong!  Short David!  It means it is incapable in its current state of trim to support the demands you're making of it.  Lots of variables available before the funeral is arranged!  Yes...it may ultimately be found to be incapable but merely pointing a finger at the scale is an insufficient examination...unless, of course, it's a 50 oz 1/2A with a sheet wing and no flaps...or even with flaps, for that matter!

Give us some info/data and we can "discuss" it!

Ted

[Shorts,David]

Wrong!  Short David!  It means it is incapable in its current state of trim to support the demands you're making of it.  Lots of variables available before the funeral is arranged!  Yes...it may ultimately be found to be incapable but merely pointing a finger at the scale is an insufficient examination...unless, of course, it's a 50 oz 1/2A with a sheet wing and no flaps...or even with flaps, for that matter!

Give us some info/data and we can "discuss" it!

Ted

Well, I am very curious. I'm speaking of my tri-motor Strega. Now, Jimby and Brett both say the problem may be with Strega aerodynamics, and not the obscene amount of weight. I may agree, because my plane only stalls on inside corners, not on outside corners, so there is some aerodynamic problem occurring. But, Strega's have 770sq in I believe. And mine weighed in at 91oz with battery at Golden State 2 years ago. The nice thing is, it has so much thrust that it recovers instantly from stalls. The bad thing is, it used to be an arc, so I get no appearance points (or perhaps half appearance points for covering depending on the CD), so I'm not too passionate about making it work, except to prove that 91 oz is not too heavy...but it might be.
  That is a video of the maiden flight. No stalling on my tight loops, but the outboard wing dips significantly on square insides.

[phil c]

Wow, the Cobra I’m presently flying is 9.44oz per sq ft. 

Gary

Gary, that's only a bit under the "10 oz/sq.ft. limit".  A few grams won't matter either way, iight or heavy.

If you like how it flies just make sure it has plenty of power to keep it overhead.

Phil C

[Mark wood]

An airplane has to weight what it weighs to do what it needs to do no more, no less. Airplanes that are built too light and need weight to fix CG issues are not built right. Airplanes built too light and wiggle don't do what they need to do. Airplanes built with stuff to make them stronger "because they need it" are too heavy. If the airplane is strong enough to survive what it needs then it is good enough. Adding carbon fiber, a fad favorite of many, doesn't do anything but add fancy and weight for bragging rights. Manage the needs and when it's finished it will weight what it needs to and that is that. I very rarely weigh my airplanes unless there is a minimum weight requirement for the class. What they weigh is basically irrelevant provided the CG is correct and they are strong enough for the mission. 

[Gerald Arana]

Even a brick will fly. But a light brick will fly better than a heavy one...

Bob Hunt

It depends on how hard you throw it Bobby! 


Jerry


PS: Most contests I've flown in have a thing called "wind" and a balloon doesn't fly well in it!

[phil c]

......From some perspectives that might be true, but given what I know about your situation, I doubt that any of them are heavy enough to make any significant difference. It is very rare indeed to find a stunt airplane that won't fly simply because it is too heavy.......
[/quote

I've judged stunt a fair amount over the years.  The one telling factor of a "too heavy" plane is that they require excellent pilots.  I saw more crashes from an overweight plane falling out of the sky in any maneuver that includes "overhead" time( above 45deg) than anything.

The other issue, particularly for newer flyers, is over controlling when the plane is up over 45deg.  Make a mistake, and instead of whipping the plane through, damn the score, they way over control the plane to try to make it go somewhere it can't go.
Seeing a plane crash because it stops flying from over control is pitiful.

You've gotta know when to  quit and sacrifice what will obviously going to get a lousy maneuver score.

[Ken Culbertson]

......From some perspectives that might be true, but given what I know about your situation, I doubt that any of them are heavy enough to make any significant difference. It is very rare indeed to find a stunt airplane that won't fly simply because it is too heavy.......
[/quote
The other issue, particularly for newer flyers, is over controlling when the plane is up over 45deg.  Make a mistake, and instead of whipping the plane through, damn the score, they way over control the plane to try to make it go somewhere it can't go.

You've gotta know when to  quit and sacrifice what will obviously going to get a lousy maneuver score.

This is really overlooked by a lot on fliers.  You have to know the limits of your plane, and the only way to know it is to push it to it's limits at a safe altitude.  I rarely see anybody, even our other local experts do that anymore. I cringe when I see a flier try and save the shape of a maneuver when the plane is already outside it's envelope and the OH8 is the worst.

Ken

[Avaiojet]

An airplane has to weight what it weighs to do what it needs to do no more, no less. Airplanes that are built too light and need weight to fix CG issues are not built right. Airplanes built too light and wiggle don't do what they need to do. Airplanes built with stuff to make them stronger "because they need it" are too heavy. If the airplane is strong enough to survive what it needs then it is good enough. Adding carbon fiber, a fad favorite of many, doesn't do anything but add fancy and weight for bragging rights. Manage the needs and when it's finished it will weight what it needs to and that is that. I very rarely weigh my airplanes unless there is a minimum weight requirement for the class. What they weigh is basically irrelevant provided the CG is correct and they are strong enough for the mission.

Yes, build the model for the purpose. Absolutely.

I know of a model at 42" in span and weighs 82 ounces. No, not one of mine.

That certainly sounds heavy, however, without seeing the model and the building efforts, plus the many functions which the model has, full blown scale BTW, 82 ounces can be considered "reasonable" for this particular model.

I don't care about weight either. Choose wood correctly.

I have no models over 55 ounces, and it's just the way they came out. One, the first one I sold, was a bit heavier, the buyer will only use it for static display.