HS on Dominator

[Randall]

I have a partial Dominator that came with what appears to be a plans-built HS. It has an inverted airfoil which I assume is to counter the forces of the pod and windscreen as opposed to the symetrical HS of the nose pod Dominator. Is this correct or should both Dominators have the symetrical HS?

Thanks!

Randall

[MikeBoyette]

Randall,
That's how Dad used to build them. I am not sure if the metal tails are the same way or not. He also used to twist one wing one way and the other the opposite way. This was to counteract the tourque roll. This worked pretty well with the original composite tails, but I don't think it can be done with the newer metal tails.

[Randall]

Thanks! The tail that I have appears to be a wood, fiberglass, and possibly foam tail. I'm going to drill out a couple of rivets to to make sure what I have. I just wanted to make sure that the inverted airfoil woudn't be a problem.

Thanks again!

Randall

[MikeBoyette]

Randall,
If it is a plans built tail then it is wood on the verical section and fiberglass on the horizonal section. If this is true then there should not be any rivets. The all metal tails Dad sells now has many rivets. I am confused.

[Doug Riley]

I can't speak for the designer, but in general a machine with thrust line below the CG (such as the Dominator) doesn't need the inverted-airfoil HS (or negative incidence on the HS, which is the equivalent). Prop thrust pushing below the CG performs a similar function as long as the prop is making significant thrust. A symmetrical airfoil with zero incidence works fine in this case.

The inverted airfoil would simply add to the nose-up bias that the engine already creates. It might even cause the nose to swing more than you want it to as you change power settings.

[Randall]

Maybe it is all aluminum because of the rivets. It's smothered in primer which I've been hesitant to remove chemically and too lazy at this stage to sand through. I"ll chip some off to make sure. It does have the inverted airfoil and rivets, though.

I'm temped to drill out the rivets holding the HS on and building up a symmetrical one to add back to the existing rudder.

Thanks guys!

[GyroRon]

Take a picture and post it Randall.

[Jonvee]

I took Ernie’s plans and stretched it to 64 inches to fit my prop. I really did not want to work with fiberglass so I made a second tail and cut it in half for the horizontal. Sorry I don’t have any pictures of the spar I made to hold it together. But it is based on the plans. Ernie’s method of building is real easy and makes a strong tail. 15lbs. I just recently added the anti-servo tab. Makes all the difference.

[Randall]

Sorry it's been a while, but the jury's back in. It's an aluminum HS. I'm tempted at this point to srtip the bondo and primer and remove the HS and build a symmetrical version partly because I'm not sure whether I'm going to reinstall the nose pod or not. I'm inclined to leave it open.

[CLS447]

John V.,

I am so glad you have started posting. I have been impressed with the workmanship of your machine since the first time I met you at the convention in Waxahachie TX. Since my new machine is powered by an Ea81 I have become even more interested in your machine. Is there any chance you are going to Mentone?

I would love to have the opportunity to pick your brain and take a new perspective of your machine. If not, I would like to do it openly on this forum. Thanks.

[Jonvee]

Hey Chris,

I will not make it to Mentone this year. Feel free to ask about anything. I love the EA-81. Mine is not hopped up very much. It does have a two barrel carb I purchased from Helicopter Ed.

[CLS447]

Ok Jonathan V. Is Jon Alright? How about I move my line of questioning under "engines- EA-81" heading? I'll see you over there.