BALANCE WITH A CANARD LAYOUT

In Figure 12.4 the canard layout is shown. All the same principles apply. The centre of gravity and the lift are arranged to produce no moment, but since the mainplane is cambered, the foreplane must produce a balancing upload. (This is one of the claimed advantages of the canard, but to anticipate a later paragraph the arrangement shown in Figure 12.4 would be dangerously unstable, aerodynamically. It would need ‘fly by wire’ devices to fly safely.)

Since, here, the forewing is lifting, it produces downwash which affects the angle of attack of mainplane behind it, but if the forewing is relatively small and of high aspect ratio, this is not a large effect It is worth noting all the same that whenever two or more lifting surfaces are in proximity, they do have mutual downwash effects. The forewing also lies in the vortex-induced upwash of the rear plane, which is a significant point

As with the orthodox layout, the forewing must produce the required balancing load in all trimmable conditions. In a dive, the load on the foreplane will be up, to prevent the bunt