Canard Wing Aircraft
Canard type airplane is an airplane which the horizontal stabilizer is placed in front of the wing. The term “canard” may be used to describe both the aircraft itself, the wing configuration, or the foreplane. This fixed-wing aircraft that feature a small foreplane or forewing located in front of the main wing. This unconventional design, often described as “backward,” offers some advantages besides disadventages over traditional tail-mounted horizontal stabilizers.
Notable Examples
Several notable aircraft utilize canard wing designs, including:
- Gripen fighter jet
- Saab 37 Viggen
- Rutan Voyager ultralight aircraft
According to Peter Kämpf in aviation.stackexchange.
Pros and cons of a canard wing design are:
Pros
- The force to effect flight path changes works the right way, so pitch response times of canards are slightly better than those of a conventional configuration.
- The wing can be further aft, so in short business jets the cabin might not interfere with the wing spar.
Cons
- The induced drag at off-design points is higher than that of a comparable conventional configuration.
- The bigger lifting surface must keep some stall margin, so the total lift coefficient will be smaller than that of a comparable conventional configuration. In the end, a canard will need more wing area.
- Control surface deflections will add to the already high lift coefficient of the canard plane, increasing lift demands on the surface with the smallest margins.
- The highest lift coefficient is needed at the surface with the smaller Reynolds number. Normally, the reverse would be better.
- If the engines are mounted below and ahead of the wing, they will be hit by the wake of the canard, reducing intake efficiency and compressor stall margins.
- To make sure that the control surface will be the last thing on the plane to run into compressibility problems, it should have less lift coefficient and more sweep than the wing. In the end, a statically stable canard will have a lower cruise Mach number than a comparable conventional configuration.
- The landing gear must be made to retract into the fuselage, because the wing is too far behind the center of gravity to allow the gear to retract into the wing.
For more articles click.
