Low aspect ratio sport plane ideas

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WonderousMountain

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Attached is a Martin H. Airfoil meant to be used on my custom propellor (4 blade). It is 18% with high camber, might be useable blended on centerline. The expanded thickness conducted by airfoil tool Routine.
Coordinate file has compatibility issues with forum, can direct message.
 

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nestofdragons

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Nice work. Yes, looks like you could go thinner on the wing, down to the knee and shoulder level. Maybe make the cockpit/canopy slightly wider at the shoulder level.

Just curious - what is your target MTOW, wing area and cruise speed?

Have you thought about moving the rudders further back, like the early Rutan designs, with the rudder aft of the trailing edge?View attachment 125843
My goal is FAR103. At this moment wing area is 14,2 m2. Cruise speed is not important to me. If it flies, it is ok. I like the idea of basic flying.
 

nestofdragons

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Nice work. Yes, looks like you could go thinner on the wing, down to the knee and shoulder level. Maybe make the cockpit/canopy slightly wider at the shoulder level.

Just curious - what is your target MTOW, wing area and cruise speed?

Have you thought about moving the rudders further back, like the early Rutan designs, with the rudder aft of the trailing edge?View attachment 125843
Also ... your remark about placing rudders more backwards: that would be interesting if i didn’t want to create something with small overal dimensions. Only if i cannot get pilot on CG of wing, i might consider leaving idea of straight trailing edge.
 

rotax618

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If you want the takeoff run like a Verhees Delta, use the same UC. The airplane should be able to accelerate in the lowest drag attitude and then rotate to best angle of climb when it reaches flying speed, landing should allow the aircraft to rotate to a high lift high drag attitude to flair without the tail touching first or the nosewheel wheelbarrowing.
 

nestofdragons

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If you want the takeoff run like a Verhees Delta, use the same UC. The airplane should be able to accelerate in the lowest drag attitude and then rotate to best angle of climb when it reaches flying speed, landing should allow the aircraft to rotate to a high lift high drag attitude to flair without the tail touching first or the nosewheel wheelbarrowing.
Makes sense
 

nestofdragons

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Another reason why not to choose for Verhees like landing gear is length of the legs. Little Bird of Hatfield landed at about 15 degrees AoA. I drew that angle for my idea and this was the result. I guess i would prefer short legs. And if i start using thin wings and a part of the fuselage under the wing, i might be able to create shorts and a easy system to retract the wheels inside the body. I take Opal Facet as inspiration for that.
 

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erkki67

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Koen, and the weight savings with a Verhees layout, have you considered this too?
Your leading edge and wing bottom is going to be glazed anyway, so the forward sight is still granted.
 

rotax618

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If you use the Verhees UC, i doubt that your design will have sufficient directional control without a central fin and rudder in the prop slipstream.
 

nestofdragons

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I started drawing the thin wing using the Marske M-35a airfoil. 12,7% thickness. So ... it should have less pilot inside the wing. A pod or fuselage is needed. So why not install some part of the pod at the underside of the wing just to make landing gear less long.
I was doing a quick draft. I only drew a single wheel at the back and ... then it hit me. Maaaaan, that rear leg will be very short if it should be central. And why not keep a central edition of a trigear. Small wheels at wingtip. As close as possible to the axle line to the rear wheel.
This way we get the lowest drag during take off run. We get short legs, which should be less heavy. And it is rather easy to retract it due to its central placement and short leg.
Ok, where is my idea going wrong? I am sure i forgot something.
I place a old draft to compare with the longer legs needed if there is no pod at the underside.
 

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cluttonfred

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I like the thin wing with the pod all on top of the wing better than this iteration. The sight lines for the pilot will be better the higher his/her eyes are above the wing, too low and all you’ll see is wing on takeoff and landing. The better visibility will also negate or reduce the need for transparent panels in the wing itself.
 

challenger_II

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Here's a thought: with the wing cell you have drawn, place the cockpit and engine underneath, similar to the arrangement on the Mitchell A10. May not be as "clean" a design as desired, but the arrangement would solve several issues that have been discussed, i.e: landing gear arrangement, ease of entry/exit, pilot visibility, etc.
 

nestofdragons

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Here's a thought: with the wing cell you have drawn, place the cockpit and engine underneath, similar to the arrangement on the Mitchell A10. May not be as "clean" a design as desired, but the arrangement would solve several issues that have been discussed, i.e: landing gear arrangement, ease of entry/exit, pilot visibility, etc.
True. I might try a mix of SWIFT-hangglider pod with my wingproposal. It can still be very low.
 

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