Villa

Back in February 2008 I posted my new Twin Tail SPAD. I want to add the latest experience to it but the original post was cluttered with other info so I have decided to bring it back fresh.

Last year I totaled my Twin Tail SPAD. It was about 4 years old and had originally been my Pusher Puller. After the two .28 Magnum engines wore out I converted it to a single engine with an OS 46 AX engine, keeping the original twin booms and tail feathers. This version is a better match for a single engine configuration with all new fuselage, tail booms, and tail feathers. Symmetrical 48" wing with 13" cord including 2"ailerons; rear of engine to LE=6-3/8"; TE to end of booms =16-11/16"; booms on 16" centers; CG = 3-1/2 inch but will soon move back a little; AUW = 5LBS; extreme duty 5/32 dia torsion bar main gear with simplified mounting; 6 servos with four inside wing; receiver and battery also inside wing. Currently will not snap roll so I may reduce the vertical stab areas to do some experimenting. Spar has three hard points made from 1/4" aircraft plywood and 1/4-20NC blind nuts to support the front of the 1" X 1/16"square aluminum fuselage and the front of the two 1/16" X 3/4" X 3/4" aluminum boom angles. The ailerons are from the booms out. Between the booms are two 4MM dia carbon rods inserted into two flutes of the rigid portion of the aileron section to provide stiffness.

Villa

About 6 months ago I drove the plane into the ground at full speed when I took my eyes off for a second to look behind me. Broke the engine mount. I used the radio on a Gyrocopter that I recently abandoned due to many crashes while learning to fly it. A few weeks ago I made a new engine mount out of cutting board and put my SPAD Twin Tail up in the air. To get it to snap roll I was forced to reduce the area of the two vertical stabs. Now it snap rolls like a demon. It does super great hammerheads. The hammerhead is one of my favorite maneuvers. It does them with out a hint of roll as is common on most of my other planes. Two days ago I was doing hammerheads and noticed that the plane easily rotated more than 180 degrees. Now we all know that a hammerhead is 180 degree rudder turn about the yaw axis, from a vertical start. So on the next hammerhead I held full rudder longer than usual and made a HAMMERHEAD 540, which is 1-1/2 full turns. For me that is a new maneuver, and HAMMERHEAD 540 is my name for it. I'm sure others have done it before me, but I have not seen or heard of one in my 36 years of flying RC. The next day I went to the same field and could not do my new hammerhead. Today I tried again 3-4 times and again, I could not do it. Apparently I was not paying enough attention the time I did do it, and now I'm not sure how to repeat it. I'll get it again, and this time I will take notes. I have heard that old people have to do that. I'm only 73, but I'll take the notes anyway. I'll take some new photos this week to show the smaller vertical stabs and post them here. I would like to point out that I have 4 servos inside the wing, plus the battery and the receiver. Access is from the bottom of the wing thru hinged doors in the 4mm Coroplast. The top of the symmetrical wing is completely clean.

draftman1

it sounds cool Villa. I need to do a twin tail sometime, one of my favorites! looking good!

jaav

I like the use of the torsion type set up on the UC..What size is the piano wire?

I have a 52 4stroker and 61 2c dont know witch one yet...See how the build goes.

The plans I was searching must be from the mad Russian...Sorry Vorna.

Villa

Hi jaav
The piano wire is 5/32 inch in diameter. I always bend it cold. Occasionally one would break in the vice and leave a horrible jagged break. I used a grinder to cut a groove in the top of the vice jaws into which the wire fits, and rounded the bottom of the groove so that the inside radius of the bend was at least 5/32 inch. I have never broken a wire since. I do use a heavy leather glove on my hand nearest the wire when bending the wire. Note that one cutting board support must be installed on the wire before the last bend is made in the wire. An improvement I recently made replaces the hole in the cutting board with a 5/32 inch wide vertical groove into which the wire goes. A hole below the groove can now be used to tie the gear in place with heavy string or a plastic tie wrap. The improvement I just described makes better sense if you are looking at one of my photos showing the landing gear with the plane up-side-down. You will be the first to use this change since I have not yet used it. Twice when I was making the last gear I forgot to insert the cutting board gear support while bending the wire. Let me know how it works. Ask me here for any other information you need to build this Twin Tail SPAD. Have you seen the plans for the two SPAD plans I did post here, a Flying Lawnmower and a pusher prop Canard, both 46 size planes? I would love to see those two flying in Australia. Only one has been built in the USA that I am aware of. My drawing plans are very detailed and I wonder if that has turned off some builders. The planes are very easy to build and are extremely strong. Each lasted me about 5 years. Go for it!

draftman1

I need to build at least the canard, Villa, I will someday. I have been engulfed in the SSC warbirds and havnt looked at anything else. plus it has been combat season. ee gads, too many planes to build

jaav

5 years! il lucky to get 6 months before I do some thing stupid and plant it. Must admit the Balsa plane Im a lot gental with but dont fly them often, they dont grow! Hail the spad.

jaav

New motor, controls cables and the corro has landed..Just awaiting the ally angle and the tortion wire.

jaav

Doing #2 wing, the scale up was a little to big, that wing will go on the modified USS..

Villa

As can be seen in the photos at the top of this subject, I mount four servos plus the receiver, battery, and switch inside the wing. The servos are mounted as shown on the attached photo, using three drops of CA glue and a plastic tie wrap. The door hatch is cut into the bottom of the wing as shown. The hatch is held closed with bamboo skewers inserted into the bottom wing flutes. Sometimes I use electric tape to hold the hatches closed. The attached photos is of my Pusher/Puller plane.

jaav

A pic of the 2nd wing in progress..A little heavy..This plane is going to be used as a heavy lifter..Have a couple of foamys that will have rockets mounted on them and fired from the SPAD..one of them is a B29 that never flew it will now..

the wing is now compleat...
Villa, I like the the door hatch latch....

jaav

Ok some more build pics.

Villa

Hi jaav
What is the wing span on your Twin Tail plane? What size engine are you planning? The torsion bar main gear I use should work on yours. I have an idea for simplifying the torsion bar mounting that I can give you if you are interested. I forget if I already mentioned it above.

jaav

Villa,

The wing span is 55 inch, 13 inch chord, 16 inch from TE to LE on tail. 61 2 stroke.

1/2 way through the UC but Ill have a look.

Villa

I am very happy to see you building the Twin Tail. I suggest you start your own build thread rather than use mine. You have some excellent ideas and that deserves a separate thread. I asked you about your main gear in my last post. Do you have that firmed up? Just as a point of interest, my Twin Tail started as a Pusher/Puller. I flew it that way for about 3-4 years until I wore out the two .28 Magnum engines.

Villa

Hi jaav
I have been looking every day for posts showing your twin tail plane. It is summer in your Australia now, so you must be flying all of the time. Anything new to show us? I have always flown year round, but last year, and especially this year, the cold is brutal on me. We had our yearly chili fly-in last Saturday and had a good turn out even though the temperature was 30 degrees F. I flew my SPAD Twin Tail yesterday and today. The attached photo shows my latest version, sitting on the Engine Starting Safety Stand I designed/copied/improved. We have ten of them at our field. I can send you the free plans if you are interested. The temperature got up to 50 degrees F. today so it was perfect.

PatrickCurry

My Feedback: (20)

Hey, there's Villa!  Nice pic.  And I like that the uprights are shorter on your safety stand.  I'm only 5'8" and although I've never done it myself, I've seen folks eat the uprights when they were moving their plane out of the safety stand.  I guess the ones at our field are the "standard" measurement safety benches but the uprights just seem a little high to me.  Anyway....  What about it there Jaav, how's it going on the build?  

jaav

Yep the twin flys every weekend...I am doing vids.

jaav

Still having a lot of problems with rudder flutter. keeps breaking the support wires. total AUW 3.8kgs.

rolls like there is no tomorrow, and still bends the front UC at landing..Have just got some more piano wire for a new type of UC..

What sort of winds do you fly it in? 2 weeks ago it was gusting to 35kts. A few old vids of it.

http://www.youtube.com/watch?v=WaSWhraK7fU

http://www.youtube.com/watch?v=nL36kor8bu4

http://www.youtube.com/watch?v=yuRkShWwYQE

Villa

Please scroll back to the beginning of this post to see what I am referring to. Two days ago I totaled my SPAD Twin Tail. I was 2-3 mistakes high and diving at full throttle. When still safely high I gave it up elevator and the response was very slow. I wondered why and took no positive action. Hit the soft ground at full throttle at about 70 degrees. This morning I finally inspected it and found the probable reason for the crash, other than pilot error. I expected the elevator servo to be partially stripped. It was in perfect condition. I held the rod to stall it and it felt strong. It stalled, then kept working when it could move again. I inspected the elevator and all seemed good. I then moved the elevator with my hand and was surprised how stiff it was. I then recalled a few times in the air noting that the elevator was not responding in proportion to my stick movement. I never did anything about it. Forgot. Getting old. Next time I will add some slots to the Coroplast elevator hinge, like I have done to many of my other Coroplast hinges. I could have saved it if I had throttled down. I think I will scrap the Twin Tail and rebuild my SPAD Flying Lawnmower.

jaav

Its the simple things that get you!!!