Designs

Aircraft design has always been a big interest of mine. I've been studying on my own and have picked up enough to do some first order conceptual designs. That's usually enough to get good ballpark performance and weight estimates. Quite a bit can be learned by doing parametric studies of different airframe elements and I've spent hours and hours tinkering with different variables.

Here are a couple designs that made it far enough to sketch in CAD. None of these have been flown or ever will be built as drawn. There is too much missing detail and almost no stress analysis work. These are simply ideas that capture my interest. None of them are radical departures from existing designs. They each have one or two details that set them apart to make it interesting to me. As you can see, most are some form of glider.

VW Motorglider

Motorgliders are a big interest. This one is a 80hp VW touring motorglider configuration. It is inspired by the Fournier RF-4, but is constructed a bit differently. This one would be a steel tube fuselage with a composite wing. Another variation would be lighter and powered by a 1/2 VW with wings partially covered in fabric to save weight. With the right attention to drag details, this should easily accomplish a 20:1 glide ratio and possibly as high as 25:1.


Primary Glider

This one is on the other end of the scale in complexity (or lack thereof). This is a simple primary glider very much inspired by The GOAT series of airchair ultralight gliders. The only significant difference is a more traditional wing construction and more precise airfoil. The goal here is very low stall speeds in the low 20's, low minimum sink at a low speed and a glide ratio approaching 20:1 if possible. If it climbs well, the lower glide ratio would be less important.

The Super 26

This sailplane is intended to be in a similar performance class as a Russia Ac-4, but with a slightly lower glide ratio, but a flatter drag polar. It is also intended to climb better at a lower speed. This would give the glider an advantage in marginal or weak conditions without giving up too much on the high speed runs. Construction would be similar to traditional composite sailplanes, but probably all carbon fiber to minimize weight. The overall design goal is to create a glider that is as much fun and utility as a SGS 1-26, but with enough performance to keep it interesting.

AcroCassutt

This design actually got finished to a very high degree. It was a variation on the Cassutt pylon racer that was optimized for aerobatics instead of speed. The drawn engine is the seven cylinder HCI radial. The actual engine was going to be an O-200 or O-235. It has a much larger wing area than a racer and the tail volumes are larger as well. The gear sit much closer to the stall angle of attack at three point than the racer gear. I actually got as far as welding up the fuselage and building wing ribs before deciding to buy the Pitts. The fuselage is still sitting in the hangar having mostly served as a welding refresher.

FW-190A

This is an idea that I would love to see finished out. It's a scaled down (about 3/4) version of a FW-190A. The planned engine is one of the Rotec nine cylinder radials which are about 150hp. It would need retracts to really make it look right, but the rest of the construction could be very much like an RV. The tapered wing would be a pain because of all the rib fabrication, but the end result would be really fun. A good ship for chasing down some of those Titan TF-51's.

Microlift Sailplane

I've been intrigued with the microlift soaring techniques written about by Gary Osoba while flying the Carbon Dragon prototype. The Carbon Dragon is an incredible design, but requires several thousand hours to complete. I've drawn up several deriviative designs for microlift soaring. This is one of the more recent configurations. All up weight of the empty airframe would be around 150 pounds with a gross weight under 350. Stall speed should be less than 20 mph with the Vne at only 65-70 mph.

Pusher Motorglider

Another variation on the motorglider theme. This one benefits from possible lower drag and seating similar to a pure sailplane. It is complicated by the low wing and complex cooling problems as a pusher.

Ultralight Glider

This is another simple glider not much different than a primary glider. This would fall into the same performance category as the Superfloater.