Canard Aerodynamics: Why You Might Not Want a Canard Airplane

Your videos are just way more interesting bro...easier to watch.. it doesnt feel like a classroom

Interesting video. My buddy in an early Velocity during testing did stall the rear wing. He went to full right aileron, full right rudder, full nose down, and full power. Eventually the plane started dropping off to the right and into a knife edge, gained speed and started flying again. Took 5000 feet tho. But even with the rear wing stalled the plane is dropping at a slow decent rate and likely survivable.

Just like with your montage clarification video I have huge respect for you Scott that you strive to rather have the correct info out rather than ego boost. Kudos

As a total fan of the canard design airplanes I appreciate this video 📸 excellent work ty 🛬🛬🛬

Great job on making such a detailed follow up video with multiple rounds of corrections. The world would be a far better place if more people were a like you.

The whole thing with the swept wing and aspect ratio comes down to one simple concept...spanwise flow is inefficient so avoid it if at all possible. Higher aspect ratio wings have less chord so spanwise flow is reduced and thus provides a higher lift:drag ratio. Sweeping the wings back increases spanwise flow because even at zero AOA, there is spanwise flow equivalent to the angle of the sweep. The more sweep or AOA you give it, the more spanwise flow you'll get. Take it to the extreme and imagine a 100% swept wing, basically folded all the way back like a kitfox in transit. In that configuration, you have 100% spanwise flow and your wings are almost useless (they'll still make some lift, but not much). The other extreme is AOA with a low aspect ratio (imagine a wing with the same chord as its span), keep increasing AOA of this wing all the way to 90deg, the air will hit the center of the wing and flow in all directions....forward to the leading edge, back to the trailing edge, and out to the wingtip all at the same time, this could also be considered 100% spanwise flow as the air simply radiates outward from the center of the wing. Your wing is useless as anything but an airbrake at this point. Decrease the AOA of this wing to say 45deg and you'll notice that all the air is flowing rearward and spanwise at around 45deg, tons of air spilling over the wingtip which is very inefficient but making some lift. Swap that wing with a high aspect glider wing at 45deg and you'll see that the air is still traveling out at 45deg but very little of it is actually able to spill over the wingtip, now you're making the same lift but with far less drag. This is how aspect ratio and swept wings affect aerodynamic efficiency. Swept wings are only an efficient gambit when you're talking transonic and supersonic flight regimes, and it's not because spanwise flow reduces at those speeds, it's because the shape delays transonic flow and shock waves from being created. It becomes less important to gain efficiency from aspect ratio and more important to gain efficiency by reducing shockwave buildup the faster you go. As you mentioned, swept wings in slower speed canard aircraft are only there to get the vertical and rudder far enough back to effect a positive change and inherent stability in that axis. As for canards not being able to use flaps...well that's not entirely true. If you could aerodynamically balance the flaps with leading edge slats then there would be no change in pitch moment and no need for elevator input. You'd gain considerable lift and the flaps wouldn't act like elevators that pushed the nose down, giving you either slower stall speeds or more efficiency by not needing as big of a wing.

I appreciate the effort you put into making sure your facts were right.

Unfortunately the propeller is also flying through disturbed air causing a lot of stress and inefficiency. It's also prone to damage from rocks and debris.

In my case you are talking to a non-pilot of limited technical background. I found it to be informative in a manner I was able to follow. Anytime you have alternatives you will find people telling everyone why this new idea is the greatest thing since sliced bread. Probably the most significant thing you said in the whole video is "there is no free lunch." I want speed and efficient fuel use. You pointed out where the lunch is paid for, higher takeoff and landing speeds and a longer runway needed. I am not going to be trying to land in little back-country meadows. I also liked how you mentioned to not try to compare this plane with a Cessna 172. All in all, a great presentation.

I had a Varieze and sold it and I have been kicking myself ever since. Perhaps a velocity or a standard cozy is in my future. Canards aren’t popular because of its configuration but if a standard pilot could fly one for 5-10 hours opinions would change. Very safe efficient airframe.

Great information!!!! I enjoy still learning new things about things thought i thoroughly understood. I work on my friends velocity from time to time and i have a never ending joke of "It goes through the prop." Loose cowling screw?... "It goes the prop". FOD? "it goes through the prop". Money? "it goes through the prop". I have seen some battle scars of canard planes and things pinging off the props too. Anyways, nice videos thanks for another one.

I respect that you admit your mistakes. I think others would go on the defensive and get into attack mode.

Very interesting to hear your corrections, thanks for including the original takes. Hearing the misconceptions said out loud and then the explanation of why they're incorrect is actually a lot more information than just hearing correct facts

Because you seem to like the technical details - that 'optimal wing shape is an ellipse' thing has a whole lot of assumptions baked in, its not merely an aerodynamic argument, its how to maximise efficiency with a mechanical spar with weight and stress limitations such that the extra lift at tips doesnt disproportionately add to bending moments at the root. Different spar designs and overall weight distributions have very different optimal wing shapes.

Great explanation of the pros and cons of a canard.

Thank you for uploading this. I was excited to hear what he shared with you!

The rear stabilizer in a conventionally configured aircraft is an upside-down wing. Inverted. It's lift component is downwards. It counteracts the CofG which is forward of the Main wings centre of pressure.

IDK how I came across this vid, but glad I did. Absolutely fascinating comparisons. I'm not a pilot (wish I was) but have a keen interest in fluid dynamics & aviation. Can't wait to watch ur other vids!

Double bonus points for putting out a correction video! But now you have to make another one. You can have a vortex or vorticies, but not a vorticie :(

I own a canard and I think that every airplane is a compromise in design. These aircraft are designed to optimize for good cruise performance, that pilots really like. This optimization results in choices that reduce drag like less wing area and less frontal area. I think if they had more wing area the takeoff and landing speed they could be more comparable to other light aircraft but that would also increase weight and drag and also reduce cruise speed. Another factor is weight growth. Since these are homebuilt people can add items that add weight like avionics and upholstery and really nice paints that can make them heavier also reducing their takeoff performance. One plus of these is the overall simplicity of the design. I had a instructor once show me how you can make a steeper final approach at a slightly reduced power and on landing flair the speed can be bleed off faster making a shorter landing distance. It works but you have to make sure you keep your speed up to a safe level to avoid a hard landing. Overall the increased speed is very impressive and perhaps worth the tradeoffs.