20-09-2013, 06:23 PM
I'm procrastinating so I might take a crack at it as well 
Spoilerons are the opposite of flaperons. The ailerons will jointly move upward to dump ("spoil") lift, while still maintaining a (reduced) capacity to generate roll through opposite displacement.
The choice of whether to use spoilerons or flaperons - or neither - is dependent on the characteristics of the airframe. Flaperons increase lift and thereby potentially reduce the stall speed of the plane, but there is a trap. Being farther outboard on the wing than "real" flaps, flaperons (ailerons) are more prone to sudden laminar flow separation - a sudden stall. Since the condition is almost invariably asymmetric, the result is a "tip" stall, an uneven collapse of lift which causes one wing to dip far more than the other, thus inducing roll and a change of flight direction. This of course tends to happen on the final approach when airspeeds and altitude are already low, and there may be insufficient time and space to correct.
Spoilerons make no attempt to improve lift. On the contrary, they purposefully reduce the wing's efficiency, in order to increase the glide slope. That is a legitimate means of shortening the landing if the plane has adequate lift in reserve, and if the landing gear and structure can absorb the impulse. The advantage is that the tendency to tip stall is reduced or eliminated, since laminar flow separation is not being threatened. The disadvantage is that landing speed is not inherently reduced by spoilerons. Another disadvantage, again depending on the airframe characteristics, is the reduced aileron throw. Once both ailerons are flicked upward, their capacity to induce roll is correspondingly decreased.
On a "full house" wing with flaps, ailerons, and individual "addressability" through having four separate servos driven through four radio channels, the options multiply:
Reflex: slight raising of both the flaps and ailerons to get as close as possible to a symmetric wing profile and thus reduce drag. Done to increase speed at the cost of losing lift.
Camber: slight lowering of both ailerons and flaps, to achieve the exact opposite of Reflex.
Crow: spoilerons deployed (upward) at the same time as the flaps go down. The intention is to kill lift without pitching up or down. The downward force vector of the spoilerons should be precisely counteracted by the flaps. If not, the elevator(s) can be programmed to compensate.
With all of these configurations it can be useful to employ the transmitter's "slow" servo deployment option, or (rarer) a separate electronic unit in the plane to delay servo travel over a say 5 second period. The intention is twofold. First is to prevent sudden jerky movement of the plane after control surface displacement. Having both ailerons trip upward in ~20deg spoileron can make the plane fall out of the sky like a brick. The other reason to slow down the servos is to reduce the likelihood of overpowering the BEC and thereby causing an Rx brownout. This is particularly important with reflex/camber/crow when up to five or six servos can all experience transient current spikes when a switch is flicked on the transmitter. By slowing down the deployment of the control surfaces, current peaks are reduced as well.
Or the short version... depends on the plane. Try it high up and see
Spoilerons are the opposite of flaperons. The ailerons will jointly move upward to dump ("spoil") lift, while still maintaining a (reduced) capacity to generate roll through opposite displacement.
The choice of whether to use spoilerons or flaperons - or neither - is dependent on the characteristics of the airframe. Flaperons increase lift and thereby potentially reduce the stall speed of the plane, but there is a trap. Being farther outboard on the wing than "real" flaps, flaperons (ailerons) are more prone to sudden laminar flow separation - a sudden stall. Since the condition is almost invariably asymmetric, the result is a "tip" stall, an uneven collapse of lift which causes one wing to dip far more than the other, thus inducing roll and a change of flight direction. This of course tends to happen on the final approach when airspeeds and altitude are already low, and there may be insufficient time and space to correct.
Spoilerons make no attempt to improve lift. On the contrary, they purposefully reduce the wing's efficiency, in order to increase the glide slope. That is a legitimate means of shortening the landing if the plane has adequate lift in reserve, and if the landing gear and structure can absorb the impulse. The advantage is that the tendency to tip stall is reduced or eliminated, since laminar flow separation is not being threatened. The disadvantage is that landing speed is not inherently reduced by spoilerons. Another disadvantage, again depending on the airframe characteristics, is the reduced aileron throw. Once both ailerons are flicked upward, their capacity to induce roll is correspondingly decreased.
On a "full house" wing with flaps, ailerons, and individual "addressability" through having four separate servos driven through four radio channels, the options multiply:
Reflex: slight raising of both the flaps and ailerons to get as close as possible to a symmetric wing profile and thus reduce drag. Done to increase speed at the cost of losing lift.
Camber: slight lowering of both ailerons and flaps, to achieve the exact opposite of Reflex.
Crow: spoilerons deployed (upward) at the same time as the flaps go down. The intention is to kill lift without pitching up or down. The downward force vector of the spoilerons should be precisely counteracted by the flaps. If not, the elevator(s) can be programmed to compensate.
With all of these configurations it can be useful to employ the transmitter's "slow" servo deployment option, or (rarer) a separate electronic unit in the plane to delay servo travel over a say 5 second period. The intention is twofold. First is to prevent sudden jerky movement of the plane after control surface displacement. Having both ailerons trip upward in ~20deg spoileron can make the plane fall out of the sky like a brick. The other reason to slow down the servos is to reduce the likelihood of overpowering the BEC and thereby causing an Rx brownout. This is particularly important with reflex/camber/crow when up to five or six servos can all experience transient current spikes when a switch is flicked on the transmitter. By slowing down the deployment of the control surfaces, current peaks are reduced as well.
Or the short version... depends on the plane. Try it high up and see