[YEAGER007]

The canard also reduces air resistance because it creates positive lift unlike a conventional tailplane that produces downforce to pitch the nose up.

Conventional tailpanes don't work like that. Quite the reverse, they add a small measure of lift to keep the tail from dropping. But the main benefit is a 'steadying' effect, which is the entire point of adding one to your aeroplane.

As a matter of fact it works exactly like that when you pull back on the stick. We're talking about the tailplane in relation to the rest of the aircraft, not the ground. I’m obviously not suggesting that it constantly produces negative lift. Why would you think that?

A tailplane and its control surfaces are more than just a mere measure of stabilization; it is an airfoil that is capable of attaining both positive and negative lift thanks to the elevator. A rear horizontal tailplane is also not an absolute necessity for stability... There are many aircraft without rear horizontal tailplanes and many of them are very high performance aircraft.

The tail of an aircraft will also not just “drop” like a brick without a rear tailplane, because an aircraft is always balanced around the spar of its main wing. Aircraft are never designed to be “tail-heavy”. The tailplane is in actual fact not supposed to support the weight of the aircraft like the main wing. Its function is to provide control over the aircraft, not to keep the tail in the air. In fact, during cruise a tailplane shouldn’t provide lift, it should be as neutral as possible. This causes the least amount of induced drag.

When you pull back on the yoke the elevator is deflected up, causing the tailplane to act like an inverted wing, just like the wing on a F1 car is an inverted wing. There is no difference in basic concept between an elevator deflected upwards when you pull back on the yoke, and an F1 car’s rear wing. If you’re not convinced, just look at them in profile and notice the resemblance in the basic concept. Of course, unlike the car’s wing a tailplane is capable of both positive and negative lift.

When you pull back on the yoke, the elevator deflects up, creating negative lift on the tail. This negative lift does in fact, despite what you might believe, cause the tail to lower in relation the main wing (CoG). This puts the aircraft in a nose-up attitude, which increases the angle of attack on the main wing, resulting in an increase of lift on the main wing. When climbing, the negative lift created by the tailplane in relation to the main wing cancels out a certain percentage of the main wing's lift, increasing the total amount of induced drag and making the combination less efficient.

When you push the yoke down, the elevator deflects down, creating positive lift at the tail and raising the tail in relation to the main wings. This puts the nose in a downward attitude, decreasing the angle of attack on the main wings and reducing lift on the main wings. Again the tailplane works against the main wing, which decreases the combination’s aerodynamic efficiency.

Notice how maneuverable unlimited aerobatic aircraft are… When they pull up hard there is a HUGE amount of negative lift pulling the tail down in the opposite direction of the main wing’s lift, otherwise they would never be able to do the aerobatic maneuvers they are capable of.

In a canard design the canard produces positive lift during a climb in order to raise the nose, which added with the main wing's increased lift (due to the increased angle of attack) makes it more aerodynamically efficient.

Common sense, really. And one doesn’t need to be an aeronautical engineer to understand the concept either. 8)