My understanding is that this is due to vibration from the engine, and less rigidity from a profile fuselage.

Single-cylinder engines cannot be 100% balanced without doing oddball things like using contra-rotating shafts.  Electric engines can be fully mechanically balanced, and consequently will only vibrate in torque, and then much less bad than a piston engine.

Beyond that -- I dunno.

Hi Motorman ...
Wait a minute! That ain't your given name. What do we call you? Handles don't cut it here, we all should know each others' names, even if you log on with a handle.
Sorry, but it's one of my foibles. Please sign your name. There ... I have discharged my duty as moderator ...

Keith's point about twisty tails causing problems especially in wind and turbulence is right.
The age old thing about IC and profiles was all about vibration and fuel foaming; though electrics can suffer from flexy motormounts that allow the prop disc to tilt.
Twist on the other hand is no problem.

hope that hepled,
  Dean Pappas

I think the Sr and Jr records for endurance were set with the old rules and are no longer valid.

So we really just need a teenager or two of the right ages who are willing to build models.  "Hey kid, stick with me and you'll set a national record!"

I don't mind screen names because, I don't know that person, never going to meet them anyway so, they can call themselves anything they want what's the difference? All I care about is their knowledge and good cheer. Besides, a screen name can look like a real name and not be that persons real name so, you never really know anyway. I was Gene Simmons for a while over on SS until Len figured out the bass player from Kiss doesn't fly planes. Have you seen Second Life? this is the internet, people create entire worlds for themselves. You can be a cat or a dog or an airplane with a girls head if you want. The thing that you might understand is that some people are a little nervous about putting their real name out there in this crazy world.

Gif

I've been reading your posts for quite a while and finally had to put in my two cents. Boy, have you got the wrong attitude. If all the people on this forum thought the same way you do, we would not have the good friends in this hobby as we do.  I've been in this hobby over 30 years and it's a great feeling to meet the people you converse with over the internet. That's why it's important to know peoples names.  You have asked questions on different topics and one time somebody gave you some good advice, and your response was, I have a mentor and he doesn't agree with you.
My advise to you is stick with your mentor and don't ask anybody's advice. He seems to know it all!!!
and if you keep this attitude, don't be surprised if nobody responds to your questions.
 

Just look at any of my posts and you will see how to get in touch with this grumpy old man if you don't want to use the PM.   Will have to look myself to see if my cell phone is there.   By the way I am getting grumpier each day and have decided if there are those that don't like my posts, too bad.