The 2026-2027 AMA Control Line Scale Rules have been published.
https://www.modelaircraft.org/sites/default/files/events/rule-books/2026/Control_Line_Scale_2026-2027.pdf

Per the revision log, the only change involves the static scoring of Fun Scale.

As I read, the new deal is 0 or 10 points. All or nothing.  Anything that is at all "scale" with documentation gets the full 10, otherwise, nothing.

Correct Paul - the revision states:

6.4.3. Fun Scale Static Scoring. Static score will be zero (0) or ten (10). Ten (10) static points will be awarded to contestants who show documentation of outline and color resembling the subject aircraft, or similar aircraft of the era. Published 3-views, with or without color or markings, or box top renditions, are acceptable for documentation. Color and markings do not have to be specific to the model presented. That is all that is required to receive the full ten (10) static points. 

Fun Scale is intended to provide a Scale event which, while requiring a realistic Scale flight, minimizes the Scale research and model construction efforts. 

We will see if this helps to encourage additional participation. And remember, the contestant is not required to be the builder of the model.

I view this as a positive fix to an issue that got me OUT  of fun scale.

I design and build my own models and get scores of 8-to-9 in Fun scale.  The competition uses RC ready-to-fly planes that are perfect scale in every way.  By the old rules these toys were correctly given 10 points.  With the generous way flight points are often awarded, the 2 points was a death penalty.

So now you can build a plane that passes for scale and compete on an equal basis with RC toys.

I like fun scale because I don't have time to build much and can fly scale without having to and will build some scale models at some point.

Quote from: Matt Curtis on May 03, 2026, 10:36:40 PMI like fun scale because I don't have time to build much and can fly scale without having to and will build some scale models at some point.

Great Matt - looking forward to you next Fun Scale Model. 

I've got mixed concerns over what will be acceptable for "Fun" scale. Seems like any Rabescale stunter would be legal for the full 10 points, while maximizing the flight points, vs, a simplified sport scale subject that might not be be capable of as many flight options. I'm not trying critize the event or rules, just looking for the edges of the box the event specifies.

I recall a sport scale event in Tucson decades ago where a profile bearcat stunter was entered. Did EXECELLENTLY in the flight portion. (may have been Mr JH himself)

Regarding the BOM rule, I truly understand not having the time to build but, speaking for myself, that doesn't satisfy the itch. Too much like showing up at an Iron Chef competition with a Domino's pizza.

I have ideas for the event next March, can pull'em off? Dunno. Gotta get the ringmaster finished and see if I can still fly .

Quote from: Michael LeGate on May 18, 2026, 08:57:37 AMI've got mixed concerns over what will be acceptable for "Fun" scale. Seems like any Rabescale stunter would be legal for the full 10 points, while maximizing the flight points, vs, a simplified sport scale subject that might not be be capable of as many flight options. I'm not trying critize the event or rules, just looking for the edges of the box the event specifies.

I recall a sport scale event in Tucson decades ago where a profile bearcat stunter was entered. Did EXECELLENTLY in the flight portion. (may have been Mr JH himself)

Regarding the BOM rule, I truly understand not having the time to build but, speaking for myself, that doesn't satisfy the itch. Too much like showing up at an Iron Chef competition with a Domino's pizza.

I have ideas for the event next March, can pull'em off? Dunno. Gotta get the ringmaster finished and see if I can still fly .

Michael - thanks for the feedback.  Fun Scale is intended to provide a Scale event which, while requiring a realistic Scale flight, minimizes the Scale research and model construction efforts. The idea is to encourage folks to fly a scale event without having to commit to building a "more scale" model.  My wife Kathy flies a profile Goldberg Shoestring in Fun Scale (3-line throttle). The throttle allows for plenty of flight options (touch & go, missed approach, taxi, engine control, etc.) and she is very competitive with it.  It would be great if folks with Rabescale stunters jumped into Fun Scale - I welcome them all.

And then if folks want to continue in scale events, there is 1/2a scale, profile scale, sport scale, team scale, authentic scale, and F4B scale (in order of increasing complexity).  Yes, some folks will grumble about ARFs (or Rabescale stunters) in Fun Scale, but it is all to encourage additional participation.

Am I reading the flight requirements for 1/2A correctly? Take off, 10 laps, landing and realism in flight only. No throttle or stunts?

yes 10 laps and land

Quote from: Michael LeGate on May 27, 2026, 11:04:47 PMAm I reading the flight requirements for 1/2A correctly? Take off, 10 laps, landing and realism in flight only. No throttle or stunts?

You are correct - Here is the 1/2a Flight Scoresheet...  Just get your 10 laps in and you are done.

That's the way it has been since they reduced the multi-engine bonus from 5 to 2.  Actually from 10 to 4 since the score is the total of two flights.

I usewd to fly a twin when the bonus was really overwhelming.  Maybe it still is.

I see it like this: Takeoff and level lap plus two judgement laps = four laps.
Level flight ten laps plus two judgement laps = twelve laps.
The engine could quit at this time after a total of 16 laps.
Maybe some judges start counting the ten laps from the moment of release, but I wouldn't bet on it.
I carry at least 16 laps worth of fuel.

After reading this the old DOC may have to dust off his Midwest ME-109 that I flew at St Louis years ago.  The killer was I could not get the engine to quit at the end of the flight which was the end of flight of taxi to stop.  Still have plane in the rafters with three line set up.  May have to move radio set from plane it is in to the 109.

Quote from: john e. holliday on May 29, 2026, 07:44:37 AMAfter reading this the old DOC may have to dust off his Midwest ME-109 that I flew at St Louis years ago.  The killer was I could not get the engine to quit at the end of the flight which was the end of flight of taxi to stop.  Still have plane in the rafters with three line set up.  May have to move radio set from plane it is in to the 109.

Great - looking forward to seeing the ME-109 flying again

Take a look at page 12.
If somebody has some pull with AMA, please try to make it so 1/2A is not shown as a subset of Fun.  This is just correcting an admonistrative oversight, not a rules change,

If I did the page layout it would be:

6.4.4 1/2A Scale Static Scoring

5.4. Mufflers.
The engine must be equipped with a muffler to limit noise output except
for ½ A engines.

Just nitpicking on the definition of "muffler". How effective does it need to be? I've seen many that didn't do much for noise and some that weren't much more than a piece of lightweight tubing deflecting the exhaust rearwards.

Quote from: Michael LeGate on June 11, 2026, 02:07:19 PM5.4. Mufflers.
The engine must be equipped with a muffler to limit noise output except
for ½ A engines.

Just nitpicking on the definition of "muffler". How effective does it need to be? I've seen many that didn't do much for noise and some that weren't much more than a piece of lightweight tubing deflecting the exhaust rearwards.

I think it best to not arouse the monster to define what a muffler for CL Scale should be.  Right now, it just says that a muffler is to "limit noise output".  That should be fine.  There should be no need to define what a muffler should look like or to define any kind of noise limit.  Right now, the rules do not require what a muffler should look like or how much noise the the engine should be limited to.  Contests for these things are not being flown next to a church on a Sunday morning.

I flew a model in the Precision Scale event at a Nationals several years ago.  After I had run the engine in the pit area, a competitor filed a formal protest that my model did not have a muffler.  My model had an OS 60H and had what could be called a "tongue muffler" on it.  I countered that the rules do not specify what a muffler should/must look like.  Neither did the rules specify any noise level limit (and they still do not).  Essentially, the Contest Director asked if I would agree to noise test, which I agreed to.  The CD brought equipment and operators from the RC area and set up for the test.  I ran the engine at full speed, then at low speed, I was able to remove the muffler, then opened the throttle to match the RPM previously set so that noise measurements were made with the engine operating at the same speed, with and without the muffler.  I do not remember what the dB difference was, but it was several points.  The CD remarked that if there was only 1 dB difference, then the muffler requirement was satisfied.  I was allowed to continue with that model in that competition.

Yes, that model with that "muffler" was LOUD, but the muffler satisfied the rule.  The "muffler" was an exhaust extension with a plate bolted on the end of the muffler that was flush with the cowl surface and had multiple holes drilled into it.  Really, it was not more that a very short tongue muffler.  But it did offer some reduction in noise and was deemed that it met the rule requirement to reduce noise though no dB or noise limits had been set.

I think the only person who objected to the CD's decision was the person who submitted the protest.  This is the same person (person #1) who was a victim of a protest at an earlier contest where another person (person #2) had protested person #1's electric powered B-29 when it did not have "mufflers".  This is when the rules were later changed that CL scale electrics were exempt from the muffler requirement.

There is more to the story if anyone is interested.

Keith

Thanks Keith. We're on the same page on that rules interpetation

Quote from: Michael LeGate on June 11, 2026, 02:07:19 PM5.4. Mufflers.
The engine must be equipped with a muffler to limit noise output except
for ½ A engines.

Just nitpicking on the definition of "muffler". How effective does it need to be? I've seen many that didn't do much for noise and some that weren't much more than a piece of lightweight tubing deflecting the exhaust rearwards.

Muffler rules have been around since the early 1970's.  At first I was afraid that they would lead to decibel limits and testing with meters.  But in practice, anything more than a wide open exhaust qualifies as a legal muffler in stunt and scale.  F2D is the only event I know of that has volume and exhaust hole specification.

Tongue mufflers are a token joke of a muffler, but they have been accepted for a long time.  With no expansion volume and enough holes to equal the engine exhaust, the damaging shock waves zoom right through with minimal loss of impact.

I don't judge Scale, but if I did I would not downgrade a score due to an exposed muffler that actually works, or award a premium to a hidden muffler that barely reduces noise.

In reality, the events that require mufflers, stunt & scale, were the least noisely CL events, even without mufflers.

Quote from: Paul Smith on June 12, 2026, 06:52:38 AMI don't judge Scale, but if I did I would not downgrade a score due to an exposed muffler that actually works, or award a premium to a hidden muffler that barely reduces noise.
In reality, the events that require mufflers, stunt & scale, were the least noisely CL events, even without mufflers.

A psuedo-tongue muffler will probably work on my current contemplated project. A Dr Zarkov Fox spaceship muf totally destroys the visual appeal of said subject. Electric would be great but I don't have the smarts/parts for it yet.

There is not any definition of a muffler in the rules and let's keep it that way.

Additionally, the rules clearly state that no scoring penalty will be applied for exposed engines/mufflers in Sport, Profile, and Team Scale...

No scoring penalty will be applied by the judges when part of the engine(s)/motor(s) must be exposed or non-scale openings are made for engine(s)/motor(s) cooling for Sport, Profile, and Team Scale. Typical configurations include uncowled radial engines or aircraft whose shape does not provide sufficient space, such as the Spitfire or P-63. Other causes are nose or cowling sizes dictated by the scale to which the model has been built, which cannot conceal a standard type model engine(s)/motor(s). No scoring penalty will be applied by the judges for a protruding or fully exposed muffler or for the hole in the cowl or fuselage, necessary for attachment of muffler(s) to the engine(s).
For Authentic Scale, judges will assess scoring penalties for exposed engine(s)/motor(s) or non-scale openings which are made for engine cooling or exhaust and exposed controls.