F&B vs Brodak Viking

Hi Guys,

I'm not trying to start any kind of controversy here, but I do have a questions that would seem to need answering.

Question:

The F&B Plans I have show the Viking wing as a pretty normal "old time" type of construction with the spar in the center of the wing and an unsheeted leading edge that is somewhere between blunt and pointed. The ribs are made from 1/16 balsa and are uncapped. The Brodak Viking Kit has a rather pointed leading edge that is sheeted and constructed as a "C" tube wing. The ribs are shown as cap stripped behind the leading edge sheeting. Was both of these types of wing constructions used on Vikings before 12-31-52? I could use the F&B plans to construct the wing if the leading edges sheeted version is questionable as to having a pre 12-31-52 origin.

The reason i'm asking is that I really want a plane that is legal in both PAMPA and GSCB old time rules.

Thanks guys!

Jim I have seen a lot of Vikings but none ever had the leading edge sheeted. The old plans that show the Fox 59 in the plane use three spars in the center of the wing. I have seen the wing bend on some of them but they never broke. I built two vikings and I put a 3/16 spar top and bottom 1&1/2 in from the leading edge and built it like a C tube but It looked like a large leading edge. I flew it at Lincoln Park in 2001 and won first in Old time and Classic and no one had a problem with it. I used a Fox 59 in mine and it flew very well in the wind.How wide is the sheeting on the Brodak kit?

Hi Ed,

It's about 2 & 3/4" wide.

Hi Jim Here is a picture of the Viking and you can see the leading edge sheeting and cap strips. I gave this plane to Eric V in the Tampa bay line flyers and he is on here all the time so maybe he can measure the planking for us. It looks wider than 1&1/2 in. to me.

Ed,

The sheeting on Brodak's looks about 5/8" wider + or - a little. So I suppose the wing planform doesn't change any with just a little more sheeting? Of course I could reduce the width of the sheeting to match yours exactly!

a little more sheeting makes the wing stronger and has no effect on flyability. Shouldn't make any difference under either rules.

Adding sheeting and ribcaps to a OTS that was not Designed that way would be in violation of the rules. Example Ringmaster S-1 vs. S1A

Scott(just what I've been told)Riese

However, it makes a better flying plane!!!

Jim I got out two sets of plans that I have and I found the plywood rib pattern that I used. The leading edge is 1/2 inch thick on one and 3/4 inch on the other. The ribs are 1/16 on one set and 1/8 on the other. The landing gear exits the body at the leading edge of the wing but the gear sweeps forward so the wheels are 2 inches in front of the wing on one and 3&1/2 inches on the other.Also the stab and elevator is almost square at the tips on one and very round on the other. Also some plans show half ribs.???????
Also here is a picture of my second Viking that I only used in one contest and sold it. It was heavy and didn't fly as well as the first one. I also made a mistake on both of them and never caught it until later. When I built them I used 48 inch balsa and added tips but the plans show 47 Inches plus tips.I was one inch over on the span. I think most planes are built this way.On both of my planes the sheeting is 1&1/2 inches wide.I have a picture of Mr Z plane and it has half ribs.I have a Zilch x with internal spars but some people are flying a version with spars on the surface. If some one makes a mistake take away his appearance points!Maybe thats why I never got any.

The only set of Viking plans I have seen were those with the Control Line Classics kit I built. So that's all I know about how it should be. PAMPA OTS rules specifically allow (3.1.4) Structural changes to strengthen the aircraft. PAMPA rules specifically do not allow, among other things, (3.2) . . . change of airfoil. . .

The argument some would have is that sheeting the leading edge changes the airfoil.

It seems to me that any kit sold as OTS, or Classic, legal, should have a statement documenting its authenticity on the plans. If this were done, this kind of question would not come up.

It seems to me that any kit sold as OTS, or Classic, legal, should have a statement documenting its authenticity on the plans. If this were done, this kind of question would not come up.

That's up to the builder to get it right. Control line clasic IS OTS legal and is the F&B Plans

Scott(Built two of them)Riese

Ah, well...

Let's keep in mnind that OTS is NOT an Official AMA Event (Good Lord forbid!)...

I somehow got drafted into PAMPA's first OT Rules Committee, and we had a grand old time with many parts of the thing. STRUCTURAL enhancements which did not change the exterior form of the original were condoned, and in some cases, encouraged -- BUT...

Adding LE sheeting DOES change the exterior form; it does 'clean up' the airfoil --usually to the high point of the section, not so in the case of the Brodak VIKING, apparently --

...Ah, but, as an UNofficial event, there is no actual RULE which such a mod violates. It then becomes a matter of the event director at each individual meet. Some will allow the sheeted LE, some will not. And, the entrant (or potential entrant) has no recourse in appealing for his sheeted LE VIKING, or protesting against someone else's sheeted LE VIKING.

The idea, back in the earlu '80's, as it should be today, is to enjoy flying models which we spent the past 50 years learning to do better than <...grammar...?> They ARE fun, and with a few touches which do not appreciably violate the intent of recreating that benighted era, they can do well... It is the nut at the back of the handle which makes more difference than a few ounces of LE sheeting...

The original F&B kit Viking did not have LE sheeting. Regarding the "legality" of those that do, draw your own conclusion.

That said, I am in complete agreement that OTS should remain a "fun" pasttime and not fall victim to the rule-bending and nitpicking that has ruined a number of other "fun" events over the years.

All,

Well from the replies here is how I see it. Eddy's were in fact OTS legal in both PAMPA and GSCB rules because his sheeted leading edge ended well before the high point of the wing. The covering still had some sag in between the ribs as an original would have had. How much difference the sag was really is a moot point in the spirit that Mike Keville was talking about. You can use modern coverings on the wing that will mitigate how much the covering sags - and I do intend to use polyspan on the plane for durability purposes. If the minimal cap strips are used, like I intend to do, then there won't be any difference there either. So I believe that using the same amount of planking that Eddy used will result in the airplane having pretty much identical flying characteristics as an original Viking and should be relatively acceptable in both PAMPA and GSCB. I guess the CD will have the final say in the matter anyway.

Thanks for the replies!

Jim (Try Hard) Pollock