mstull
R.I.P.
As usual, I went through a lot of napkin drawings before stumbling upon something interesting for my next U/L design. It didn't come out like I expected at all. The parameters are: pusher; tricycle; easy to fly and land; quick and easy to build; light and simple; truly legal; leaning more towards a motor-glider.
The longer, under-cambered wings will use an ordinary, fabric covered, aluminum, ladder frame, with 34' span, 43" chord, supported by flying wires, and ordinary, notched in ailerons. I plan to use a 24 Hp CorsAir engine. It should climb and glide excellent with the long, efficient wings.
I'm planning to put the engine and prop under the wing, figuring on about a 50" prop. Moving the engine forward and the cockpit back, makes the fuselage structure come out compact and simple. I'll hang the fuel tank under the back of the cockpit.
The empennage structure is an open tripod, with one tube on top, and tubes coming from both sides of the lower fuselage. This will be my first design to have a true fuselage and just one rudder. The small wing chord will allow a short fuselage... short enough to fit in my trailer.
I wanted to mount the main gear directly on the cross tube at the bottom of the main fuselage triangle, but then the plane would be a tail dragger. So I had to add a second axle on trailing arms. It adds some weight and drag, but might solve another problem... getting the fuselage to fit through the door of my trailer. If I disconnect the trailing arm bungee loops, the plane will drop down 9".
With these long wings and closely spaced spars (because of the under-camber and small wing chord), the wing could easily twist adversely when the ailerons are deflected. So I added an extra set of flying wires for the outer part of the wings near the middle of the ailerons.
The ribs will be similar to the ones on my Lexan sheeted wings, using aluminum tubing for the bottom of the ribs, with styrofoam glued on top, and 1/32" plywood rib caps. I'll use a Gottingen 387 airfoil for the upper surface.
The bottom fabric will be unsupported, except for PK rivets into the rear spar, to give it the under-camber, like my biplane had in the center of its upper wing.
I'll use false ribs to minimize leading edge sheeting. The full ribs will be about 2' apart, with false ribs spaced about every 6".
I haven't worked out all the connections nor control systems. I like to solve some of that as I build. I wanted y'all to be the first to see and discus my design on these hallowed pages. Let me know if you see something amiss.
The longer, under-cambered wings will use an ordinary, fabric covered, aluminum, ladder frame, with 34' span, 43" chord, supported by flying wires, and ordinary, notched in ailerons. I plan to use a 24 Hp CorsAir engine. It should climb and glide excellent with the long, efficient wings.
I'm planning to put the engine and prop under the wing, figuring on about a 50" prop. Moving the engine forward and the cockpit back, makes the fuselage structure come out compact and simple. I'll hang the fuel tank under the back of the cockpit.
The empennage structure is an open tripod, with one tube on top, and tubes coming from both sides of the lower fuselage. This will be my first design to have a true fuselage and just one rudder. The small wing chord will allow a short fuselage... short enough to fit in my trailer.
I wanted to mount the main gear directly on the cross tube at the bottom of the main fuselage triangle, but then the plane would be a tail dragger. So I had to add a second axle on trailing arms. It adds some weight and drag, but might solve another problem... getting the fuselage to fit through the door of my trailer. If I disconnect the trailing arm bungee loops, the plane will drop down 9".
With these long wings and closely spaced spars (because of the under-camber and small wing chord), the wing could easily twist adversely when the ailerons are deflected. So I added an extra set of flying wires for the outer part of the wings near the middle of the ailerons.
The ribs will be similar to the ones on my Lexan sheeted wings, using aluminum tubing for the bottom of the ribs, with styrofoam glued on top, and 1/32" plywood rib caps. I'll use a Gottingen 387 airfoil for the upper surface.
The bottom fabric will be unsupported, except for PK rivets into the rear spar, to give it the under-camber, like my biplane had in the center of its upper wing.
I'll use false ribs to minimize leading edge sheeting. The full ribs will be about 2' apart, with false ribs spaced about every 6".
I haven't worked out all the connections nor control systems. I like to solve some of that as I build. I wanted y'all to be the first to see and discus my design on these hallowed pages. Let me know if you see something amiss.
