Brief:
Back in the mid-70s I was looking for an interesting D engine boost glider to build. During those years I was building rockets constantly so new and unique projects were always on my agenda. I had read something about a Bruce Blackistone design for a canard glider with a planform similar to the Air Force XB-70 bomber. His original design was sized for A through C engines although he may have recommended D engines. I thought it would be more fun to double the size and so this project came about. I flew the one I built back then 3 or 4 times until on one flight it flew through some high-power lines and shredded. About 3 years ago I figured it was time to build another and that is the basis for this review.

Construction:
The Valkyrie uses a bunch of balsa sheet. The primary materials you will need to begin construction are:

• (2) 4” wide x 3/16” thick x 36” balsa sheet
• 4” wide x 1/8” thick x 36” balsa sheet
• (3) 1/8” x 1/2” x 36” spruce strips
• 1/8” x 1” x 36” spruce strip
• 1/8" x 1/8" x 36” basswood strip
• BT-50 body tube
• EB-50 engine block (or substitute)
• BT-50 size nose cone
• Plans for the small model are online at The RocketShoppe.

The first step in building the Valkyrie is to build the main wings. Since I was scaling up the design, I had to determine a method to lay out the double size main wing onto the balsa. This was going to be a little difficult since the wing is so large and would require two separate pieces and a small triangle of the 4” wide balsa to be glued together. My solution was to take a large piece of scrap cardboard from a shipping box and to layout the planform on that using a ruler and doubling the sizes from the plans I had. Once this cardboard template was cut out, I lined up my two sheets of balsa such that, with minimal excess, I could trace the desired triangular templates onto the balsa sheet. The grain of the balsa needs to be aligned with the leading-edge sweep of the wing, so the template was positioned on the balsa to do this. After cutting each of the wing pieces for left and right wing the next step is to glue them together. I took a piece of wax paper the length of the joint and on our very flat kitchen countertop, I glued the wing pieces together with Titebond while keeping them perfectly flat using books as weights. Once the main wing panels have dried, I then took my Xacto knife and trimmed the leading and trailing edges. For this bird, I trimmed the leading edge with a rounded shape from top to bottom and reversed this on the trailing edge. Once I had cut the preliminary shape with the knife, I finished up by sanding a smooth curve on both edges. After this is done the tip on each wing is cut as per the plans. After separating the tips, the wing should be blocked up to the correct height and the wing tip should be reattached to the main wing creating the wing dihedral. I carefully sanding along the root edges of the main wing and tip to allow for a flush fit when joined. After finishing up the main wing I cut the upper and lower rudder pieces from the sheet balsa as well.

My next step was to build the fuselage. Bruce came up with a unique solution with his design of a T-boom. It adds little weight but significantly increases the strength of the boom. The small version uses a T-boom made from balsa, but I figured for my larger version spruce might work better. Since the boom is about 50 inches long it was going to require two strips of the spruce for both halves of the T. I used a full 36-inch length of spruce for each of the vertical and horizontal halves of the boom and then cut two 14 inch pieces to lengthen each half. For the lower half I glued these two lengths together and added a 1/16-inch-thick plywood doubler at the joint. For the upper half I did the same thing but added a plywood doubler to each side. After these had dried, I then aligned the upper half centered on the lower half and use CA glue at numerous locations down the length to glue to the two halves together to form a T. When attaching the upper to lower halves I reversed the location of the butted joints on the boom halves, so they were at opposite ends relative to each other, I didn’t want the joints to be at the same location. To finish up I then ran a thick bead of Titebond® glue along the joint for the entire length of the boom on both sides.

Next up was gluing the wing panels to the fuselage. For this glider that was very easy since the inverted dihedral of the wing tips sets the dihedral correctly. The wing root edge was sanded for a better fit into the T of the fuselage and then I glued the wings to the fuselage with Titebond. After the wings have dried, I drew the alignment lines on the wings for the outboard rudders and glued the rudders into place. I had previously sanded a symmetrical airfoil into the rudders. The small bottom fin was also airfoiled and glued to the bottom of the boom.

The canard surface was the next step. It was cut from 1/8-inch-thick balsa with the grain running parallel to the trailing edge. I simply doubled the dimensions on the plans and drew that planform onto the balsa sheet. The canard is in two pieces, the primary surface and the moving trailing edge. I sanded the leading edge symmetrical and sanded a slight rounded shape to the trailing edge. For the elevator surface I slightly rounded the leading edge and sanded a symmetrical shape into the trailing edge. I then gave both surfaces a good coat of clear dope to seal the balsa and after it dried, I lightly sanded the surfaces smooth. The elevator was then attached to the fixed surface of the canard with silver mylar tape on the bottom and top while leaving a gap in the upper top tape for gluing the canard to the boom. The canard was then located on the boom and glued into place on the bottom of the boom per the drawing. Finally, a piece of the 1/8-inch square basswood 14 inches long was glued to the moving canard surface so that it extended from the trailing edge of the canard forward and parallel to the fuselage about 1/32 inch to the side of the fuselage. This basswood strip forces the canard trailing edge flat during boost being locked down with a tab from the pop pod. The final step in the glider build was to form two small hooks from music wire and glue to the bottom of the canard, one on the fixed surface and one on the elevator, using CA glue strengthened with epoxy. A rubber band will be stretched between these two hooks to actuate the canard elevator after pod ejection.

Pod construction was next in the buildup. The pod is a basic pop pod design and relatively simple to build. First cut a 7.5-inch length of spruce from the 1/8” by 1” spruce strip. Cut an 11” piece of BT-50 body tube. Align the spruce directly lengthwise with the body tube and glue into place with CA glue and then fillet with Titebond. The next step was to cut the pod hooks from an excess piece of 3/16” x 1/8” spruce strip. They are cut long enough to be positioned at a 45-degree angle from the T-boom joint to the bottom of the pod. Four are required and two on each side are glued to the boom with a mating face glued to each side of the pod. For this large a bird I also glued two spruce pieces to the pod near the forward end that were similar to the hook pieces but were perpendicular to the boom to act as guides to keep the pod centered and stabilized on the fuselage. I then glued two short pieces of 3/16” launch lug slightly off the wood standoff of the pod. These should be separated about 5” for the launch rod to provide good stability to the glider on the pad. Finally, the pod to boom assembly should be carefully sanded at all the mating locations so that the pod easily falls off the glider. During boost the aerodynamic forces will keep the pod attached but as soon as the chute pops out it will separate. A shock cord and 12” parachute should be installed in the pod.

Finishing:
Since this model should be as light weight as possible keep finishing to a minimum. I have seen some people simply paint the bottom surface with a fluorescent color. For my model I sprayed clear butyrate dope on the balsa surfaces and after it had dried, I sanded it lightly. This would help to protect the balsa against any water that might get on it.

Flight:
Because of the large size of this model, I launch off a kludged together pad. I took a spare piece of 1” PVC tube I had lying around and cut off a 5-foot piece. I cut one end at a 45-degree angle so I could easily push it into the ground. At the field I simply tape a 3/16” diameter rod to the flat end of the PVC and push the assembly into the dirt. The Valkyrie is then provided a long enough rod assembly to be completely suspended a few inches off the ground. A long set of electric leads is also necessary, and I usually bring a lead extension to provide for the distance needed from the launch system to my glider. It is also a good idea to secure the leads so they will not hook the glider as it leaves the pad.

I fly my Valkyrie on Estes D12s and may someday put an E9 in it. A friend also has one he flies more frequently than me and he has used E9s successfully. His glider is somewhat heavier than mine. I have even used it two or three times in competition.

Recovery:
Since the primary use of the Valkyrie is as a glider a little effort should be made in trimming it for flight. The trick to trimming a Valkyrie is that a pin is pushed through the fuselage about 1.5” forward of the trailing edge of the fixed canard surface. A rubber band is attached to the hooks on the bottom of the canard to cause the trailing edge to drop once the pod ejects. The canard trailing edge usually droops between 10 and 25 degrees as required to adjust your glider for a flat glide. Carefully toss the glider with the pin adjusted as best you can guess and see how flat the glide is. Continue this process, pushing the pin through the spruce boom is not easy, until you think you have a good, flat glide. I will admit that trimming a Valkyrie is not too easy since you cannot really get a good toss for an extended glide. However, you can usually get something reasonable doing this and after each flight you can move the pin to refine the glide. My results with this Valkyrie have been very good and I typically get 1.5 minute plus flights in dead air. Hopefully there will have been an inherent turn built into the glider, so it does not simply fly straight away from you. All of the models built here in Florida tend to have a natural turn, if not you will need to tweak a rudder or use some other method to get your Valkyrie to turn.

Summary:
The Valkyrie is a great sport bird and is what I would call a “true” rocket lofted glider. It looks more like the type of glider you would expect to be flown with a rocket engine than the more competitive but more typical competition gliders. It is also fairly straight forward to build and easier to get a reasonable glide from as well as being somewhat more robust during boost due to the design. Mine has always boosted almost perfectly vertical, even in a 10-mph breeze, and the pod separation is extremely reliable. Finally, a rocket glider on the field of this size always attracts attention, even from the HPR guys and everyone enjoys watching the flight.