It's about 2 meters span.

Full length D-tube, flat center section, a bit of dihedral on the tips.

Here is the top view, left out the last center sheet until I install the radio.

After I left Brasilia and sold my wing two weeks ago, I picked up where I left off on a project started in June. My friend Matt had mentioned an airfoil plotting program he was using to make templates for foam core cutting and I took a look at it one day. It not only plots airfoils, but it allows you to basically build the entire wing in 3D with all the cutouts for spars, webs, sheeting, te, le, etc. I just started screwing around with it until I had this sweet looking planform and I just had to build it.

Well the *free* trial of compufoil is sort of bs, as you will find the moment you click print. One sheet of ribs will print on the 100% scale, while the next is purposely skewed to prevent you from getting anything useful, especially on a tapered wing like this where every rib is different. It took quite a bit of time, but after a lot of print screen, save, print screen, resize, ......I finally manipulated the second page to print on the correct scale.

And that was the beginning: two sheets of paper with 15 airfoils for each wing half. I used airfoils that were in the compufoil database, RG15 at the root, transtioning to SD8000 at the tip. RG 15 is fairly common for thermal models, and is not at all pitch stable for a flying wing. SD 8000 is a symmetrical stabilizer airfoil, pitch neutral. I think I stretched them a little to make a thinner profile also. So the wing's stability will come entirely from twist, zero reflex. The wing was built flat but the twist will be added with the covering. My last flying wing was based on twist as well, so I should be a little closer with my twist guess this time.

Some of the simplest materials that are so easy to acquire in the states can be difficult or impossible to find here. First, at the hobby shop, which is actually a really decent store, I was only able to find balsa, no hardwood, and the balsa was only of the worst quality. It took an hour of digging through every sheet they had to pick a dozen pieces that would work. Second, I still don't know where to find epoxy. Although I know it's around, I just haven't worked out where it is sold. Number 11 Xacto blades...nope. My favorite building board, those suspended ceiling tiles used commonly in office buildings....not a chance. And finally, wax paper.....I would pay 50 bucks for a roll of wax paper right now. So the wing was built on a sheet of white styrofoam with a layer of some poly-whatever that was non stick and see through and held in place by seam pins...no T pins available. And, surprisingly it all worked great. Actually the total cost of materials to date is around R$55. $30 usd. Pretty incredible. So the entire wing has been built with only balsa and CA, not a stick of hardwood or a drop of epoxy. You get pretty creative trying to make things strong enough when you're limited. The D tube is key, but the vertical grain, full span shear webs do all the work that hardwood spars would have.

I plan on using 2 HS 56 servos in it, hitec feather receiver, and a tiny battery pack. I will ebay them back in AZ and bring them with me next time around. There are some beautiful places around here to huck this thing so it will be nice when it is finished.


Brasilia comp behind, next up Canoa

Just finished the comp in Brasilia that went pretty much perfectly except for a couple windy days. I was flying better than I ever have in a comp, although not every day. Some things clicked since the worlds and I don't even know what it is exactly except maybe I am making slightly cleaner decisions about when to top out, when to leave, how fast, left or right or straight, and I am trusting some of my own decisions more when the gaggle decides differently, and it is paying off huge. The conditions were flatlands, strong, light winds, clouds. These are my best conditions so I am still aware that I will struggle on odd days or in the mountains. The turbulence was mildly intimidating on a couple days but nothing crazy. On the worst day an Aeros pilot did an outside loop followed by a tailslide and multiple tumbles resulting in him going home the next day with a crooked glider bag full of broken shit. I was low in the same area but didn't experience that air, however I do remember having to glide with about 1/2 vg for a few miles to feel comfortable near there. Chris Smith got a front row seat and it seems that the parachute took a bit of time to open before finally popping cleanly and lowering him into the hills. Most other days were excellent with high cloudbase and good racing.

I just read a story from a blog where a pilot claims to have been climbing poorly, was advised to raise his sprogs as this would help him, and afterwards began climbing like a rocket! This and other misconceptions about how to tune a glider can have bad outcomes if taken to extremes. In this example, obviously he hasn't compromised his safety since he is raising his sprogs, but raising the sprogs and improving the climb are completely unrelated assuming he doesn't climb with full VG, just as lowering the sprogs beyond a certain level is completely unrelated to bar pressure. I see a lot of gliders with way low sprogs and questionable setups. Perhaps it is time for a compilation of the collective knowledge of comp pilots, designers, and manufacturers in a format understandable and useable by all pilots of comp wings. The wings are so similar now that almost all techniques can be transferred between different gliders. It would be great to see it on a cd with video from inside and outside the sail, all vg positions, tip wand positions, mid section concentric changes, cg changes, ballast, varying amounts of reflex/flaps, etc, all in a controlled condition with the same pilots on the same gliders, maybe gliding against each other after one makes a change and the other does nothing, and so on. I think an intelligently edited version of this would be a huge hit with people buying racing gliders.

Sold the wing here so I will be coming home with just a harness with clothes stuffed in it. That will be a nice change. I'm picking up the new wing, tuning it up, and heading down to the Ecuadorian coast for a week of ridge racing at one of the best coastal sites in the world. I think I could live there, the flying is so good. Sounds like the normal crew will be there plus a few other top pilots to spice up the racing event. I heard the launch was improved recently making the airflow up the dirt ramp much cleaner. Should be a great time.