The wheel of the main landing gear is lost due to a heavy landing. This plane is used for air cargo competition. The maximum take-off weight is about 15~16 kg. The take-off distance should be less than 60 m. The plane is powered by an O.S. .91 engine according to the rules of competition.
Gary:
A static margin of 10 to 30% MAC is reasonable. The more stable the aircraft is statically, the more control deflection is needed to maneuver or change flight condition. You can't really compare, in terms of mass distribution, the electric RC model pictured to the Velocity experimental aircraft which has piston engine and wing-integrated fuel tanks.
First to the pros:
The RC Plane would appear to support a lower landing speed, and decreased wing-tip stall risk on landing - due to ground effect: The rear position of the main wings permits the wings to be closer to the ground on landing (and TO).
With the Main Wings swept, they act a good bit like tail-feathers. In a high-speed pitch-up, the end-bits will push the nose down: in a slow-speed stall, it's important that the stall speed of the forward wing is higher than the rear wing - in which case, it is like impossible to stall the main wing.
So in what flight mode is the plane least statically stable?
I think above makes an argument against dual wings (or a canard with equally-performing wings).
Maybe you could explain that some more, stable is quite good in this world. My next project is likely to be a canard so quite interested in your thoughts
Judging based only on this picture, it seems this airplane has a serious design issue. A canard configuration with rear-swept wing results in a neutral point location too far behind the CG, making the aircraft too statically-stable in pitch. This will limit severely the (payload) weight you can place in the forward section of the fuselage. You could fix this by increasing the size of the canard surface to bring the NP forward, or by redesigning the fuselage to get the CG further back.
Comments
A static margin of 10 to 30% MAC is reasonable. The more stable the aircraft is statically, the more control deflection is needed to maneuver or change flight condition. You can't really compare, in terms of mass distribution, the electric RC model pictured to the Velocity experimental aircraft which has piston engine and wing-integrated fuel tanks.
First to the pros:
The RC Plane would appear to support a lower landing speed, and decreased wing-tip stall risk on landing - due to ground effect: The rear position of the main wings permits the wings to be closer to the ground on landing (and TO).
With the Main Wings swept, they act a good bit like tail-feathers. In a high-speed pitch-up, the end-bits will push the nose down: in a slow-speed stall, it's important that the stall speed of the forward wing is higher than the rear wing - in which case, it is like impossible to stall the main wing.
So in what flight mode is the plane least statically stable?
I think above makes an argument against dual wings (or a canard with equally-performing wings).