Canards and long runways, why do we need them?

[CutieDarkFae]

I keep reading that people need what some people consider insanely long runways for their canard planes.

 

Ignoring the question of what constitutes 'insanely' here, why do they need such long runways?  Lack of acceleration?  Lack of deceleration?  What can we do to make this better?

[Kent Ashton]

It depends a lot on horsepower, prop and CG.  Personally, I don't like to operate in less than 2500' (160hp EZ + climb prop) or 3500' (180 hp Cozy + cruise prop).  Sometimes, 4500' for takeoff seemed barely enough in my Cozy IV heavy on a summer day with two people in front.

 

On takeoff with a level deck angle, canards do not have much AOA.  Lowering the elevators changes the chord line and increases canard AOA but the airplane won't fly until the canard develops the lift to rotate the nose.  Once the nose rotates, the canard's own AOA increases and tends to over-rotate the nose but that is easy to recognize and stop with the canard somewhere below the horizon.  So you roll until the canard will lift the nose, establish a takeoff attitude, then fly off a bit after that.  There is no "short field/soft field" takeoff procedure in a canard airplane.

 

For landing, a flying attitude is already established and can be maintained through touchdown if the pilot anticipates the touch so it's possible to land a bit slower than one can take off.

 

I am finding that my EZ has a lot of thrust at idle--1100 RPM compared to around 850 in my Cozy, although static idle rpm is about the same--and that makes it hard to slow down.  I try to remember that if I needed to stop short, kill the engine.

 

The Cozys have a further complication over the EZs in that two people in front moves the CG forward and the canard has to go faster to lift the nose.  That will also raise the landing speed slightly but the effect of forward CG is most noticeable on takeoff.

[Marc Zeitlin]

I keep reading that people need what some people consider insanely long runways for their canard planes.

 

Ignoring the question of what constitutes 'insanely' here, why do they need such long runways?  Lack of acceleration?  Lack of deceleration?  What can we do to make this better?

First, they don't need "insanely long runways", or even particularly long runways, so the rest of your questions are moot. I regularly go into 2300 ft. runways at SL with two people and half fuel in my COZY MKIV, and would have no compunction about going into 2100 ft. runways if that's all there was. Not at MGW, though. Density altitude and CG location make a large difference in takeoff roll.

 

I can get into almost every paved runway that I'd be interested in going to. The runway requirements are not particularly different from other low wing area, high performance aircraft such as Glasairs and Lancairs.

 

If you want to use shorter runways, you can add a lot of power (O-540) for getting out and a C-S prop, VG's on the wing and canard (not a lot of data on actual stall speed reduction, although a lot of claims), trailing edge fences (same comment) and very heavy duty brakes for getting in.

 

And the comments about needing "flat approaches" is incorrect as well - while many canardians fly their aircraft that way, it's hardly necessary - just poor training. These planes will come down fast if you know how to fly them and are willing to slip. I rarely fly my approaches at less than 5 degrees of glideslope (PAPI's and VASI's are generally 3 degrees), and I can do steeper than that if required.

 

And let me put in a request for actual names in signature files, so that we know who we're talking to.

[CutieDarkFae]

Why is my last question moot?  Is there nothing that can be done to improve this?

 

 

If you want to use shorter runways, you can add a lot of power (O-540) for getting out and a C-S prop, VG's on the wing and canard (not a lot of data on actual stall speed reduction, although a lot of claims), trailing edge fences (same comment) and very heavy duty brakes for getting in.

VG? (Sorry, sometimes I'm not up on the terminology, yet) But what you're saying does imply that it is acceleration and deceleration that are the key improvements that could be made.

 

And flying them better also.

 

 

 

How does my real name help you know who I am unless you already know me somehow?

Edited October 31, 2014 by CutieDarkFae

[Kent Ashton]

How does my real name help you know who I am unless you already know me somehow?

We would hope to recognize you some day as a canard friend. The net is full of no-name posters. I just like to know who i'm talking to.

[CutieDarkFae]

We would hope to recognize you some day as a canard friend. The net is full of no-name posters. I just like to know who i'm talking to.

I'm happy to be a canard friend, and is CutieDarkFae not enough of a name for you? I prefer to keep my actual self off the internet as much as possible, I just don't trust it.

[rviglierchio]

 I prefer to keep my actual self off the internet as much as possible, I just don't trust it.

 

Ditto here....

[Marc Zeitlin]

Why is my last question moot?  Is there nothing that can be done to improve this?

Sure - like with every airplane, there are things that can be done to improve one aspect of the aircraft's performance or another. It's always at the expense of something else, however. The objection was to the notion that these planes require more runway than other high performance aircraft, and that there's something wrong with them because of their runway requirements.

 

VG? (Sorry, sometimes I'm not up on the terminology, yet)

Vortex Generators.

 

But what you're saying does imply that it is acceleration and deceleration that are the key improvements that could be made.

Well, if you want to reduce runway usage, you can either get to speed faster or reduce the speed required. Since we're not going to be changing the basic aerodynamics of the aircraft, power and brakes are about what you've got.

 

And flying them better also.

Absolutely. Speed control is paramount - you can eat a lot of runway if you're 5 - 10 kt. too fast.

 

How does my real name help you know who I am unless you already know me somehow?

It makes you more of a person, and less of a troll. I respond far better to people that I know the name of than to anonymous nobodies. This is a religious issue on the net - we're not going to solve it here. It was a request, which you're free to ignore. What I will say is that on the COZY mailing list, everyone is required to use real names and provide addresses and phone #'s in order to join. This has tended, over the 19 years I've been running the list, to lead to far higher levels of civility than on most internet fora. Take from that what you will.

 

Lastly, if you don't trust the internet, why would you bother posting questions on it?

[Jon Matcho]

I created a post in the Forum Announcements section titled Personal Information, Privacy, Civility and Community that addresses the sidebar/thread-drift here.  Please read that and feel free to continue that conversation over there.

 

I also moved this topic here to the Education/Operations section.

[Jon Matcho]

Due to devolution, this topic is now closed.  Feel free to open a new topic as you like.