I agree, sequences have gotten only larger. Once a few years back I was out practicing IMAC our site was overflown by a CHP patrol airplane. He sent a couple ground units to come talk to us because we were breaking 2,000 ft on the uplines. We have a freeway about 400 yards across the field, during rollers we have accidentally overflown the freeway. Sequence commities need to pay attention to this.

Dave Platt may have started the myth, but repeating this certainly doesn't bust it. Myth's are often started by famous people who don't think they have to prove themselves giving out tidbits as advice or trueism's. They may be true or not. To bust a myth you have to show proof, such as wind tunnel data, other lab data, calculations, or experments.

How about model deltas and flying wings need special airfoils with built in reflex to fly at their optimum speed and efficiency...?

Context is important. What 'works' or holds true in one modelling discipline may be completely different in another. This leads to misapplications...

The windmilling prop debate is an example. Stopping the prop is less draggy in most RC stuff. Yet in Free flight Rubber it's less draggy to to let it freewheel. So the 'rules' have to be correctly applied to the specific model or aerodynamic task in hand.

About elevator chord design consideration.
How thick is the airfoil...?
Do you want more or less built in sensitivity around neutral...?

I used to fly C/L slow combat with a guy who had planes with little nubby elevators [1/2" chord x 12" span] and typical thick wings. He liked the lack of sensitivity around neutral, it contributed to him being able to fly without looking at his plane so much and paying more attention to the other guy. Problem was even with the plane set with a typical CG the elevator was pretty ineffective for manuevering unless it was at full crank like a speed brake. His models couldn't consecutive loop at all, there were mostly wallowing messes on the verge of stalling whenever he tried to do anything aggressive.
He was never talked into trying more chord for many years. Years later he resurfaced with Russian built RTF planes [like a Mezjslik or a Yuvenko] that employ a good amount of elevator chord and these planes are World class flyers with just average power.

Could be, but probably hard to prove either way.

IMAC is not Pattern

Build a lightweight delta with a fast, symetric airfoil and give it better than 1:1 power to weight. 3 pounds with a strong .45 engine and roughly 500 sq inches, for example.
Get the model trimmed and balanced for hands off flight wherever it's pointed at full speed, then land it and take note of where your elevon trim is.
If everything goes to plan [in this example] the amount of up trim in the elevons will hardly be measurable.

To back up what CP just said about flying wings and deltas needing reflex...
I just built and flew a hybrid delta/flying wing how much reflex 0.0, how much up trim again zero.

A symmetric airfoil maybe but one with camber will need reflex.

No it isn't
However the current FAI sequences eat up far more sky than I ever supposed they would.
At the last WC ,this size was the "right" one -That is -what the judges wanted to see.
My son is completing a new f3A electric and will be flying the same sequences -at these same distances and lengths - Unless something changes - it is where you fly if you want to score .
If were up to me, the size would be reduced by 50%.

I'm not sure which number this is, but how about:

There is no force more powerful than WRONG rudder........

That doesn't prove anything about speed or efficiency.

Why would CHP be enforcing FAA rules for? BTW even the AC will be void if prez signs bill.

He was on patrol 500' above the freeway located 1/2 mile from our runway. When we exceeded his altitude he called it in as a near miss, then filed a near miss report with the FAA the following day.

How close was you?  A near miss at 500 feet isn't the same as a near miss in controlled airspace.    When seperated by conrollers its 5 miles or maybe less.  VFR I think its 2,000 feet.  Not sure about helicopters flying in their corridors, but see them at less than 2,000 feet all the time. 

Difficult to judge but I would say 2,000 to 3,000</p>

Well I would certainly avoid flying over the freeway, but I would challange it if this became a further issue.

I would recommend working with the controllers instead of challenging them. In San Marcos, Ca. we had a glider field just south of the 78 freeway and it was on the approach for the Carlsbad class D airport. We had a deal to stay south of the freeway and they would tell incoming aircraft to stay north. This worked for years until the city kicked us off for other reasons. You will find most people in aviation are reasonable, but the ones that aren't can make it miserable.

This was a helicopter pilot, not a controller.

But he filed with the controllers and they can warn traffic of the models, even though he is a cop to the FAA he is just another pilot.

You can't do much better than zero trim on a symmetric airfoil for speed.

The club prez is a full scale pilot and all the local small aircraft facilities know we are there. For the most part we don't have full scale traffic. For some reason a couple weeks prior to this incedent he started to overfly our field at 500' and for a few weeks after. Immediatly following the incedent, the club prez mandated that no models be flown over 400'. This was in effect for a couple months and then we went back to normal. I assume he did some behind the scenes lobbying and rectified the issue as the CHP pilot has not been seen again.



OK so lets get back to the Myths.............

An airplane on a conveyor can't take off


Run with it

Yes it can, the wheels will just be spinning twice as fast.