The Crazy Canard
Canards are not your ordinary planes. They're rather different looking from conventional aircraft. Like any craft, they have their advantages and disadvantages. So for those that want to understand them better, here's information for you.
The History Of The Canard
Canard is french for "Duck." Kind of a strange name to use for a plane, but here we are. The name appears to have originated in France (go figure) when people described the appearance of the Santos-Dumont 14-bis. Modern canards such as the Cozy do have a slight duck-like appearance with the main landing gear fixed in position. Whatever the case, the name stuck and has shown up in various places from the first airplane made by the Wright Bros to recent military jets. Despite this, they're still not very common as standard tail aircraft have taken over the airport scene.
Burt Rutan is probably the single largest influence on the canard's presence in modern days. His unique vision of aerodynamics and desires for safer aircraft that could be built with simple tools lead to many creations that have made places in history. The Voyager project used a canard wing to fly around the world while his Long EZ takes on the form that most people understand as a canard. His designs were influenced down this path from a desire to make aviation safer. One area that pilots would get in trouble from were stalling and spinning an aircraft especially in the landing phase. This is where the canard really shines.
The rotational force comes from the main wing. As it generates lift, it creates a nose down rotational moment. The tail of a conventional aircraft is used to create the opposite rotational moment to counter the main wing. That is why canards are more efficient as all surfaces lift in the same direction. To prevent stalls and spins, the canard is intentionally designed to stall before the main wing does. This drops the nose and makes the craft speed up, so in essence the whole craft never stalls (again, with proper CG). If you never stall, you never spin. One pilot tested this by doing a power on stall. The nose would drop, pick up speed, drop again, and continue bobbing the nose but the craft continued to climb at 200 fpm!
Burt's design using fiberglass made a structure that was very aerodynamic, could achieve perfect contour, and was fully supported across every inch of space making it very strong. These planes are able to do a lot with very little. With a similar engine, the canard is able to fly twice as fast while using less fuel and can carry more weight. That is why these planes are touted as having high efficiency.
However, if you read enough, you will come across some sources that talk about how canards are less efficient. As Einstein said, "It's all relative." The argument comes from the fact that the main wing on a canard cannot use the full angle of attack that it's capable of doing. The canard will stall before the main wing reaches it's full lift performance, so the main wing is under utilized. So yes, it's not as efficient from that stand point, but when you look at how much of the space on the plane is used compared to that big empty tail section on a standard plane (needed to balance out the craft) and you see the performance numbers that come on a canard using similar engines, it's hard to say they're not more efficient. Pick your battles I guess.
The main drawback of the canard design is takeoff and landing. These craft cannot have flaps as a change in lift profile on the main wing would throw off the balance with the canard that you have to have. So you have a plane that takes off and lands at 70 to 80 knots. This isn't necessarily a bad thing but does dictate two things. One is that you have to have enough runway to comfortably use (no STOL here). Second, you have to think a bit more on your approaches. It's harder to cheat your way onto the ground. The other consideration is that these craft must have paved runways for normal landings. With the propeller in the back, any loose items could kick up into the prop and ruin it.
Burt saw these things, so he did what he could to minimize the issue and came up with some neat ideas. One, the rudders are found on both winglets. These are independent of each other so you can deploy one or both. By deploying both, you effectively create a speed brake. The other innovation was the belly mounted speed brake that can be deployed on final to help increase the sink rate. Both of these help to bring the plane down easier. The speed brake also acts as a debris deflector. Anything kicked up by the front wheel that might hit the prop could be deflected by the brake when it was down.
One of Burt's most popular designs has been the Long EZ. This is a two seat craft designed for efficiency and lightness and has been a favorite among canard enthusiasts. The co-pilot sits behind the pilot to stream line the craft. It featured the belly mounted speed brake, independent rudders, and strakes that came to the instrument panel to offer some needed space. The craft is still being built by people today.
Nat Puffer, a 3M engineer, took the Long EZ design and decided to modify it to allow more space. Though you can simplify the magnitude of his efforts and say he just widened a Long EZ to create the Cozy, it would skip over the amount of work he did in engineering the plane. The final product was presented to Burt who wasn't happy that someone had modified his plane, but was impressed with the design and engineering that he officially endorsed the design (something all other canard designs never got). The Cozy became a favorite of people that needed more than two seats either for people or lots of luggage for two people. It followed Burt's example of easy to build (relatively), well written plans that go in a good progressive flow, and can be done by anyone willing to take on the task.
Many canards exist. To date, no structural failures have occurred on canards that were built correctly to plans (and that's a lot of canards, over 1000). Accidents tend to happen from pilot error or other non structural component or unapproved change. This is a testament to the composite structure and well thought out designs. They have a unique and instantly recognized profile and as long as they are operated within their intended limits they can provide function, enjoyment, and lasting memories.
Time to build and fly!
Canard is french for "Duck." Kind of a strange name to use for a plane, but here we are. The name appears to have originated in France (go figure) when people described the appearance of the Santos-Dumont 14-bis. Modern canards such as the Cozy do have a slight duck-like appearance with the main landing gear fixed in position. Whatever the case, the name stuck and has shown up in various places from the first airplane made by the Wright Bros to recent military jets. Despite this, they're still not very common as standard tail aircraft have taken over the airport scene.
Burt Rutan is probably the single largest influence on the canard's presence in modern days. His unique vision of aerodynamics and desires for safer aircraft that could be built with simple tools lead to many creations that have made places in history. The Voyager project used a canard wing to fly around the world while his Long EZ takes on the form that most people understand as a canard. His designs were influenced down this path from a desire to make aviation safer. One area that pilots would get in trouble from were stalling and spinning an aircraft especially in the landing phase. This is where the canard really shines.
The rotational force comes from the main wing. As it generates lift, it creates a nose down rotational moment. The tail of a conventional aircraft is used to create the opposite rotational moment to counter the main wing. That is why canards are more efficient as all surfaces lift in the same direction. To prevent stalls and spins, the canard is intentionally designed to stall before the main wing does. This drops the nose and makes the craft speed up, so in essence the whole craft never stalls (again, with proper CG). If you never stall, you never spin. One pilot tested this by doing a power on stall. The nose would drop, pick up speed, drop again, and continue bobbing the nose but the craft continued to climb at 200 fpm!
Burt's design using fiberglass made a structure that was very aerodynamic, could achieve perfect contour, and was fully supported across every inch of space making it very strong. These planes are able to do a lot with very little. With a similar engine, the canard is able to fly twice as fast while using less fuel and can carry more weight. That is why these planes are touted as having high efficiency.
However, if you read enough, you will come across some sources that talk about how canards are less efficient. As Einstein said, "It's all relative." The argument comes from the fact that the main wing on a canard cannot use the full angle of attack that it's capable of doing. The canard will stall before the main wing reaches it's full lift performance, so the main wing is under utilized. So yes, it's not as efficient from that stand point, but when you look at how much of the space on the plane is used compared to that big empty tail section on a standard plane (needed to balance out the craft) and you see the performance numbers that come on a canard using similar engines, it's hard to say they're not more efficient. Pick your battles I guess.
The main drawback of the canard design is takeoff and landing. These craft cannot have flaps as a change in lift profile on the main wing would throw off the balance with the canard that you have to have. So you have a plane that takes off and lands at 70 to 80 knots. This isn't necessarily a bad thing but does dictate two things. One is that you have to have enough runway to comfortably use (no STOL here). Second, you have to think a bit more on your approaches. It's harder to cheat your way onto the ground. The other consideration is that these craft must have paved runways for normal landings. With the propeller in the back, any loose items could kick up into the prop and ruin it.
Burt saw these things, so he did what he could to minimize the issue and came up with some neat ideas. One, the rudders are found on both winglets. These are independent of each other so you can deploy one or both. By deploying both, you effectively create a speed brake. The other innovation was the belly mounted speed brake that can be deployed on final to help increase the sink rate. Both of these help to bring the plane down easier. The speed brake also acts as a debris deflector. Anything kicked up by the front wheel that might hit the prop could be deflected by the brake when it was down.
One of Burt's most popular designs has been the Long EZ. This is a two seat craft designed for efficiency and lightness and has been a favorite among canard enthusiasts. The co-pilot sits behind the pilot to stream line the craft. It featured the belly mounted speed brake, independent rudders, and strakes that came to the instrument panel to offer some needed space. The craft is still being built by people today.
Nat Puffer, a 3M engineer, took the Long EZ design and decided to modify it to allow more space. Though you can simplify the magnitude of his efforts and say he just widened a Long EZ to create the Cozy, it would skip over the amount of work he did in engineering the plane. The final product was presented to Burt who wasn't happy that someone had modified his plane, but was impressed with the design and engineering that he officially endorsed the design (something all other canard designs never got). The Cozy became a favorite of people that needed more than two seats either for people or lots of luggage for two people. It followed Burt's example of easy to build (relatively), well written plans that go in a good progressive flow, and can be done by anyone willing to take on the task.
Many canards exist. To date, no structural failures have occurred on canards that were built correctly to plans (and that's a lot of canards, over 1000). Accidents tend to happen from pilot error or other non structural component or unapproved change. This is a testament to the composite structure and well thought out designs. They have a unique and instantly recognized profile and as long as they are operated within their intended limits they can provide function, enjoyment, and lasting memories.
Time to build and fly!
