"T" tail question

[turbojoe]

I'm getting ready to build my 4th Mountain Models SwitchBack and want to make this one not look like all the other SwitchBacks lying around the house. (boy, I love this plane ;) ) I've already built it as a twin but I want to do something even more different by using a "T" tail. No reason other than to have something different. My question is this: The plane already flies awesome. Will basically just moving the horizontal stab to the top of the vert radically change the flight performance? If so will it be for better or for worse? Will I need to change the stab incedence or should I stay with it as designed? TIA for any help.


Joe

[jlk]

I am not an aeronautical engineer but here is what I think I know. Moving the horizontal stabilizer on an aerobatic plane will make a huge difference. The elevator will not act the same especially when inverted. The rudder will have more coupling in knife edge flight. A good place to look for info on this would be pattern flyers. They move the stabilizer up or down on the vertical fin based on how the model controls interact. They look for a neutral position where the elevator, aileron and rudder controls do not affect each other when deflected. I would leave it alone and work on a neat covering scheme instead.

Jordan

By the way Joe, I get to Tuscon every month or so, love it.

[turbojoe]

Jordan,

I'm pretty set on the "T" tail idea. I've gotta make it work. I'm not all that worried about inverted and aerobatics in general with this plane. I have plenty of others for that type of flying. I just want it to look "different". I have a wing with retracts and another with twin motors that I can use with this fuse. That's the beauty of the SwitchBack. It's so interchangeable.

I've been to Tucson four or five times. It's a bit cooler there than here in Phoenix. About 10 degrees or so. If you want to see the opposite end of the spectrum then make the drive to Flagstaff. It's so green and cool there. 20-30 degrees cooler than Phoenix. I was there Saturday morning and thought I was going to need a jacket! Also, I haven't seen so many pine trees since I lived in Georgia. If I ever retire it'll be in Flagstaff. ;)


Joe

[jlk]

Joe,

I am sure the T-tail will work. You may find that the incidence needs to change though. I can't guess how much but I am pretty sure it will need leading edge of the stabilizer lower (positive incidence). If you can just pin or tack glue the stab on and make a gentle cruise flight to see if the incidence is right.

I have been pretty much all over Arizona, from the Grand Canyon to Nogales, Lake Havasu to Yuma and I have been in the Show low and Pinetop area. I love AZ, I am building a house in Tucson and plan to retire there in several years.

Jordan

[gow589]

Watch it if you spin it. Many "T" tail airplanes are known for blanketing the tails in spins making spins un recoverable. Often in the models we have enough power to pull them out anyway but some times that is an issue. A short spin can be quite different from a "developed spin" too.

Gary

[raptor22]

The t-tail should also mate it more effecient; t-tails are commonly used on gliders, racers, etc because it does not get wing downwash and is easier to be effeciently trimmed.

--Alex

[turbojoe]

Jordan,

Yeah, it's a real nice place here. Hotter than Hell but I still prefer it to San Diego. I moved here about 2 years ago and would NEVER go back! California sucks. I'm almost ashamed to admit I was born there.

Well, I'm getting pros and cons on the "T" tail and that's exactly what I need to hear. I started building the fuse last night and it finally entered my mind that the vertical stab is going to have to be much more rigidly mounted because of the extra loads the horizontal stab will put on it. I'll have to do some mods to the fuse I guess. No biggie. Also I have to almost double the vertical stab size to make it large enough for the horizontal to be well enough supported. I may have to get creative with a little sculpting of the vert to make it look proportional. I'm not in a huge hurry on this as I have 3 other SwitchBacks I can fly in the meantime. I just want something "different".
Thanks for the input guys.


Joe

[turbojoe]

Oops! Hey Raptor: I just noticed you're in San Diego. Nothing personal buddy. ;)



Joe

[turbojoe]

Well shoot! I've been playing around with this and got most of it cut out but I'm more interested in getting the fuse built and flown with the retract wing this weekend. All the other SwitchBack fuses I have are the earlier design with the glued on landing gear and the fuse I'm building now has the plug in version.
I have a set of plans I bought for a "T" tail twin that I plan to scratch build soon. I guess that will have to satisfy me. All the hard work was already done by someone else on that one. :D


Joe

[raptor22]

Oops! Hey Raptor: I just noticed you're in San Diego. Nothing personal buddy. ;)



Joe

Your loss......

--Alex

[jlk]

So whats the turbo Joe?

Jordan