Carbon..almost in a Spitfire in 1940 !

http://www.wingsmagazine.com/content/view/900/38/ I'll have small amounts of this wonder material.

Structure revisited...

There are still folks that think I have riveted panels. No I got rid of that thinking..there has to be really smooth surface..new glues ( epoxies ) won't give a way any slack..the rivets were to make it look a bit like a metal plane..they are totally unnecessary. I could add the rivets there ( just for the looks ), but they only mark the edges of the panels then...and possibly nearly invisible after surface smoothing and paint job. The system is pretty clever..it utilizes foam and thin plywood and carbon in 80%,15%,5% of the volume..this is a bit secret as for now..there are several details that allow this to happen in very lite and durable way.

17 points where I think the efficiency of IO excels !

I try to state few things about my design. Not only to get this idea public, but also to memorize them myself.

1. Prop disc aft fuselage is really clean ( notissably so ).

2. All tail feathers are all moving ( rudder and elevator ).

3. Fuselage aerodynamical shape has no extra bulges ( not even the canopy does not make an extra interference )..its like a fish.

4. Airfoils are designed for this aeroplane to give better performance ( XFRL5 program shows this clearly ).

5. Size is very small for a 193 cm person...length is 3740 mm ( fuse just 3303 mm long and 3033 from firewall to the end ).

6. Plane's undergear is a "trademark" design ...extra narrow....for this aeroplane...extra short too, yet suspended.

7. Plane's exhaust is buried so that the only outlet is also pushing the exhaust behind and under..no drag that is.

8. Large spinner sorta shadows the engine with its reduction gear ( no flat plate to the wind ). Still it breathes and cools down ok !

9. Air flow around wing and fuse attachment is managed so that the poor man's area ruling happens ( AR-5 site by Bruce Carmichael ). Some extra features to this added.

10. Fairly large spinner itself is big part of the drag reducing.

11. Weight through the ( volume ) 85% foam and 10% plywood and 5% carbon fibre structure has been kept phenomenally low ( 55-60 kilos ).

12. Wing does several tasks..its mild arrow shape and yet high lift with wash out and reflected ailerons ensures second to none stall spin free caracteristics and higher top speed at very low engine power.It has been also structurally optimised for very low weight and strong structure.

13. Wing tanks ( inside the wing ) add another dimesion to the planes long distance ability making it heavier and harder to cope in small size..this has been taken care with extra stability of the wingfoil and fairly large elevator area ( CG range enermous ).

14. Design sports also a clever hand rest for the long flights( I mean really long..since this flies at 0.75 liter/hr consumption too around 55 mph ).

15. The small engines ( either 150 cc 4-stroke or 175 cc 2-stroke )give second to none performance with lite weight and low consumtion ( Bailey's 175 just 1,5 liter/hr in Swift ) at moderate price. Even Radne Raket burns only 2,5 l/hr.

16. The landing gears collars work as fences when the fuselage and prop wash with increasing airspeed will make the area between collars as a ground effect generator that will rapidly ease the rolling resistance of the wheels and create lift at take off.

17. The span efficiency is not the same as with gliders, but AR 8 is normal yet the Prandtl wing adaption ought to make some difference in efficiency too compared to other similar AR wings.

Thinking the wing structure...

I have been figuring out how to approach the wing structure so that it will be easy to build and lite yet strong. My initial weight calculations made me think a half a kilo possibly should be saved still in material...and used in glue instead etc. The main problem that I have been eyeballing and thinking is the strong camber/curvature of the top side of the foil...and how to cope with that knowing that +6/-4 G as a goal ( minimum +3.8/-2). also the thickest point is hard to define in the foil and it causes headache due to the spar and spar caps...and attaching the ribs to it within my system. I have a solution to this...I have to draw it now.

FINALLY..

...GOT THE GEAR WORKING !

...AND SOME MODS ! ..for clarification..there is a box kinda bracing fork made inbetween ribs to house that system and absorber with the wheel is inside the green casing..the carbon "fork " is connected to the spar and ribs.

...and the wheel is NYLON not plastic. I have to correct it.

Corrected sketch of it !

Does IO have optimal foil ?

Someone suggested me a study for better foil; http://oddjob.utias.utoronto.ca/dwz/Miscellaneous/reno06driver.pdf and another program to study them; http://www.hanleyinnovations.com/ I just want to spend a brief moment in explaining the idea behind my foil. I interpolated the foil from existing Wortmann, Eppler, Göe, and Drela foils. Goal was to save time and use the XFRL5 program to do it. It is a compromise also in order to gain light and strong wing that is easy to build and less allergic to separation bubbles due to moisture and bugs. XFRL5 indicated that this has much more lift and less Cm than FX63-137 for instance. It has thickest point at 28% of the chord...and I claim it is still laminar...not in the sense like the 40% laminars are, but like a bird wing is. If you want to bring a NLF foil to compare...be sure it has 0,853 Cl at 0 AoA...and then I am convinced !!! Furthermore the "normal" foils that have -o.02 - o.03 Cm and 0.004 cd create Cl at around 0.23..this plane is optimised to fly at 120 km ( due to prop that is fixed ) and will gain nothing from speedier foils ( wing )in fact won't even get airborne since the great flap use will deteriorate the Cd totally in weak powered flight.

LG in Chilton DW1 style !

This ought to be the 1600 grams I anticipated. Simple and robust and only 7 cm thin !

http://www.rjmitchell-spitfire.co.uk/spitfire/images/g_type224gullwing.jpg Also SUpermarine model 224 had it ! Here is a remake after good nite sleep !

EDIT: THIS DOES NOT WORK YET !