The first set of plans for review in this issue is on theLaird Super Solution from Dr. Lyle (Jim) Pepino of Greensboro, NC. There is also a press release of the Solution in the GIANT Marketplace column of this issue.
The plans are on three sheets - First Sheet: is the fuselage, fin/rudder and landing gear. The Fuselage is constructed as noted with a crutch... made from quarter inch sheet balsa with formers and stringers attached. The front of the crutch is from hard sheet balsa and the rear is light sheet.
This airplane has a very short nose mount and all equipment installed must be kept as far forward as possible. The fuselage back to the cockpit is covered with one eighth inch sheet balsa, firewall is seven ply quarter inch plywood. The plan shows a Super Tigre S-2000 installed and it is lost in that huge cowling. Landing gear is from 3/16" music wire and is bolted to a plywood plate in the fuselage. I should think that some sort of shock arrangement should be installed to keep those beautiful landing gear fairings and wheelpants on the airplane. This airplane just drools sex... if you think real airplanes have two wings and a round engine, this is for you!
Load bearing stringers are from Sitka spruce. There is also a very good three-views and a cut-a-way drawing right on the plan sheet. Second Sheet: Wing span is 63 inch (top wing) with a cord of 12 inches - constant... lower wing spans 56 inches and has a cord of 9 3/4 inches, giving a total wing area of 1302 square inches and a wing loading of 31.85 ounces at a projected weight of 18 pounds, which should be easy enough to reach. Airfoil section is Clark "Y" and there is a 1 1/2 inch dihedral in the lower wing only. There are 38 ribs in the top wing and 34 in the bottom wing. Tips are built up. The single spar in the top wing is from 1" x 1/4" spruce. The main spar in the lower wing is 3/4" x 1/4" spruce. The rear spar on the lower wing is full depth, from 3/4" x 1/4" balsa and also forms the aileron cutouts. Ailerons are built up and are operated by a single servo operating a short 1/8" music wire Torque rod. Hinging is typical model building practice with aileron leading edges slanted rearward on the bottom and hinging at the top.
Here is where I differ with most of today's designers... both kit and plans. This kind of an arrangement on the ailerons is fine for low powered slow flying airplanes designed in the 1960's or Trainer type aircraft, but as more powerful engines are developed and marketed, I for one began to develop aileron flutter, sometimes at a disastrous cost! In the last few years I have changed almost all airplanes I have built from 60 size on up, to Frieze type ailerons.
It is a little more work, but worth it, in the fact that flutter has disappeared. The ailerons are more effective and it is easy to get differential throw. With Frieze ailerons I move the pivot point back and bush each end rib on the inside with a flanged wheel collar fastened to the rib of the fox type. Torque rod runs clear through the aileron and is installed through the wing tip, the hole being covered after final installation with a small piece of lithoplate hot stuffed on and indented in several places to simulate screws. The Torque Rod itself is usually from 5/32 inch music wire bushed in several places with outer nyrod tubing. On the inboard side I use a wheel collar with a 6-32 socket head screw as long as possible with a plastic strip aileron connector bracket drilled out to take the 6-32 screw. If you drill it out to 15/64 you can thread the 6-32 bolt in it, and adjust it to get the throw ' you want. After final adjustment, locktite the screw and the wheel collar. If you have access to some ball bearings of the proper size as I have, or had (Burroughs computers use lots of them, all sizes) you can really get smooth acting controls. Damn they're nice. Now you can adjust your ailerons either on the inboard or aileron itself, by a small hole in the bottom of the aileron through the covering and loosen the screw in- the wheel collars on the inside of the end ribs. When the final adjustment is made, again locktite the screw. With this type of aileron, when the aileron goes up the bottom of the leading edge of it is sticking out in the airstream... reducing the chance of flutter and increasing effectiveness. If you don't quite get what I am taking about, take a trip to the airport and really look at an airplane closely. Really examine it, you'll be amazed! One more thing, bush the torque rod with plastic tubing. I have found that steel and aluminum will bind up and steel and brass tubing will rust or corrode. A couple of years ago I bought a Precedent Kit of a Stampe SV4d from Hobby Lobby and it had typical designed ailerons. Recently I attended a local Dawn Patrol and low and behold a full size Stampe showed up. On checking it out, I found it had the same type of aileron arrangement I have just described. I think this is the reason the full sized jobs don't need as much control movement as our models do, anyway, it has worked for me, so you might give it some thought. Now I am no draftsman or aeronautical engineer, just a modeler looking for a logical solution to a problem and I mean no fault with Jim Pepino's plan, but in my experience, for this design to fly like the original, it should be fast, and if it is fast, I think I would have aileron flutter as presently designed. Every model we build is in the experimental class anyway, isn't it?
Jim sent along a packet of color photos, 10 in all, of the Super Solution that was restored by the EAA. The photos are great and will aid a lot in color and detail when building this airplane. It's worth the price quoted $15.00. Now if someone will design a BIG Lockheed Vega, Orion or Sirrus!
(To see the product review, click on the Giant Marketplace link at the
beginning of this article)