Sterling Yak-9 Plans?

I'm curious why I can't find plans for the Sterling Yak-9. Was the airplane that bad of a performer? I kind of like the lines of it and was checking my Internet sources for plans, but can't find any so far.

What do you fellows think of the model? Does anyone have a source for plans? Thanks in advance, guys!

Keep-Em Flying!

Probably because the original Sterling kit had no full size plans as such, just a set of what might best be termed assembly instructions with a few small scale drawings.
Richards makes a repro Yak kit, that is supposed to be of decent quality, although I haven't seen one.
No one has bothered to draw up a set of full size plans for scratchbuilders, far as I know, probably because the kits are still about in fair numbers, and the demand vs the amount of work involved to do it makes it not worth the effort.

Bill: I'm presently flying two Sterling Yaks. Both have Fox 29s, one a Sandcast, and both are swap restorations.

This Sterling perennial, along with its companion P-51, are OK flyers. Nothing to create a seance with Matt Kania about. But just OK, in the sense that, you don't want to be stranded on a desert isle with this your single CL job (At least get a Ringmaster).

True, it has flaps. But the airfoil thickness is sparse (good term, because it's not much thicker than the spar ). So there are (ahem) limitations. Streak will fly rings around it.

But you're right: cool looking, in a P-51 sort of way. Like, who cares if Jennifer Lopez can't cook. You'll look good out there. Check out all the Rooooskie paint jobs and pick one. (One of mine is camo'ed so well that you'd almost step on it). Go completely nuts and put some Cyrillic on it (like, "Adoph Has Body Odor", or something similarly clever). But the real ones had something boring like "Hero of the Patriot War Ivan Ivanovitch" or some sort.

Motors: Fox Stunt. OS 25 FP would make a killer app. OS 20 FP, if you build lightly. Any baffle 29 or 35. Most Schnuerle 20 or 25s.

I'd say go for it. Currell

Currell: If you will check your controls, I will bet they are spongy. Hold the leadouts solid and you can move the flaps up and down. Hold the flaps and you might even be able to move the elevators up and down. I had one that did'nt fly well, either. Had nothing to do with the design, it was the controls. I cut into it and put in bulletproof joiner wires and pushrods (the pushrod from the belcrank to the flap horn flexed) and the plane became a solid performer. I will stack mine with its solid controls against your Flite Streak any day. Want to try an outside loop from eight feet off the ground. I've done it.

I didn't say my Streak, just a Streak. Anyway, congratulations on your Yak. You must have a light one, too.

Another subject: I can use the FP 35/40 tonque muffler on a Fox Stunt, right? Looks like the exhaust cutout matches.

The reason I am asking is that I have another one from you definitely for the Fox, with the over and under holes and the ears. Currell

Yup, the FP 35/40 hole spacing matches the Fox 35 on all but the 50th anniversary edition. Fox made the hole spacing on the muffler just a little narrower, which worked OK when the engine just had "ears". When they brought the muffler mount all the way to the exhaust they had to angle the holes in just slightly so they could continue to use the same muffler. Now everyone else who was doing it right has to do it wrong.

I'll take a Flite Streak over a Yak any day, flaps or no. No question that the Streak is the far superior design in all respects. The Yak has it's place, which is mostly nostalgia.
They can be made to fly decently, but they are no match for a FS, or any comparable design.

jake: I would agree with you. Len's assertion re his Yak astonished me. But, hey, I've learned a lot from these BBs. He wouldn't lie...man of the cloth and all that

Seriously, Len, please weigh that Yak and report back to us. Again, I think (thought) that the thin airfoil limited its turning ability.

Len: Not to keep belaboring the point, but I know you read the article that Wild Bill wrote, addressing what is in the title, above.

And he used real combat ships, too.

Maybe what you're talking about is a BiSlob type turn. Not really a loop. But how do you do this with a Yak?

But... if you insist...I've seen or heard of stranger stuff in this wonderful hobby of ours. Currell

I am talking about turning down and around. It may not be pretty, and the plane is going pretty fast (a lot faster than I would normally fly a "pattern" ship), but it does that type of turn. I guess I was just trying to say that with stiff (read that solid) controls, the plane will turn. With whimpy controls, it won't. Been there. Done that. And the way the kit is designed, you will usually get whimpy controls doing it "their way".

On a related subject, I have an original design (well, just slapped together back in my "formative years") that has no flaps and an elevator that goes up and down about 80 degrees. If you give it full up, it will do a stall loop, or whatever you want to call it (I call it a "dipsy-do") in that it seems to just stop and rotate on the lines. Take it up to about 45 degrees and give it full up and it will rotate that way losing a little altitude each time. You can get about 10 or 12 of them before you have to straighten it out. If you neutralize the controls when the plane gets the nose aimed up, it will just fly itself out and be on its way again.

Strange things these airplanes. Those are "crowd pleaser" maneuvers, but won't win any stunt contest today.

>Currell: If you will check
>your controls, I will bet
>they are spongy. Hold the
>leadouts solid and you can
>move the flaps up and
>down. Hold the flaps
>and you might even be
>able to move the elevators
>up and down. I
>had one that did'nt fly
>well, either. Had nothing
>to do with the design,
>it was the controls.
>I cut into it and
>put in bulletproof joiner wires
>and pushrods (the pushrod from
>the belcrank to the flap
>horn flexed) and the plane
>became a solid performer.
>I will stack mine with
>its solid controls against your
>Flite Streak any day.
>Want to try an outside
>loop from eight feet off
>the ground. I've done
>it.
>

Hi Leonard,

That's impressive if you started rightside up. Not quite so neat if you were inverted! (VBG)

All fun aside, I built Yaks as a kid because my brother Gary built Mustangs and, as in everything else, we had to compete with each other. I can't remember if they were any good or not. What I do remember is that we had a good time.

Ted
>Leonard Neumann

The Sterling Yak-9 plans are available from Bill Schmidt,
4647 Krueger, Wichita KS 67220 $8.00 P.P.
He advertises in PAMPA. The May/June issue on page 30.
These plans are the type you can build from . not the isometric type that were original.
Bigiron

If you keep the weight down to 30 oz. or less the Yak with a Fox 35 is an excellent flyer. The only problem is that the judges tend not to take it too seriously. I believe that this is because it is a small plane and does not present itself as well in the air as some of the larger models. But for pure flying enjoyment, it's hard to beat.

Bigiron,

Thanks for the tip and directions. Just like you said it was on page 30 in May/June Stunt News. I must have looked right at it and didn't see it. Jeez, I guess I had better clean my classes...again!

I appreciate all the tips from the other builders and will keep them in mind. Later...

Have fun and keep-em flying!

> The Sterling Yak-9 plans
>are available from Bill Schmidt, 4647 Krueger, Wichita KS 67220
>$8.00 P.P. He advertises in PAMPA. The May/June issue on page 30.
---------

I received the Yak-9 plans from Bill Schmidt in the mail on Saturday. I mentioned in the letter/order that I had been helped by you and this forum. Bill was very prompt and the plans are great. He has high praises for you, Bigiron!

Thanks for the help!

It seems I have seen this and the Mustang in old hobby shops that have gone pure r/c, but they always seem to have these two planes,with dust on them, in the back corner. As to a four foot loop, I had a profile combat plane, WW One combat, a Fokker Triplane with Voss paint scheme, that flew very slow, but would literaly flip over on it's back and not stall. Tight turns, not loops actually. Drove everyone including me nuts.

Anyone want a mint kit for $80? Friend has one. currell

I've got a kit of the Yak-9. I've heard people say that it was only marginal in performance. I was going to redesign the wing using a NACA 0018 airfoil (18% thick). Seems like this should improve the performance quite a bit. Has anyone ever tried something similar, and if so, how did it work out.

I had both the Mustang and the Yak. One look at those thin wings and I built three Magicians. We did use them in what we at the time called slow WW2 combat. Profile of a WW2 fighter, .35 stunt engine (no BB or pressure), 60 foot lines. I did use a voodoo wing in one once. Flew fast and had more manueverability. I guess that is how it's spelled.

My guess is that it would help quite a bit.