Norman

[Norman]

I'm thinkig of buildig a modified Ibis type canard. Single seat. Is it best to have ailerons on the canard? Or have the whole canard controlable? Norm

[Len Evansic]

You don't want your ailerons on the canard, because it is so highly loaded and designed to stall first. If you had ailerons there, instead of on the main wing, you would have a very difficult time controlling the plane in even the slightest bank, with unintentional and almost uncontrollable pitching.

 

Think of the canard as a forward tail. Outside of V-tail Bonanzas with rudder-vators, no other plane uses the horizontal stabilizer for bank control. Even on the Bonanzas, the ailerons are still on the wings, and the V-tail combines the rudder and elevator actions. The horizontal stabilizer and elevators are for pitch control and balancing the CG with respect to the center of pressure of the main wing. Likewise, the canard and the elevators on the canard are for pitch control and provide lift to balance the CG load with the main wing.

 

-- Len

[Marc Zeitlin]

.... If you had ailerons there, instead of on the main wing, you would have a very difficult time controlling the plane in even the slightest bank, with unintentional and almost uncontrollable pitching.

You might want to read the "Canard Pusher" newsletters #6, 7, 8 (and maybe a few more). The original VARIEZE had combination elevator/ailerons (Burt called them elevons) on the canard. Testing of this aircraft went reasonably well, and although Burt later changed the design to a more conventional layout, it exhibited none of the "unintentional and almost uncontrollable pitching" that you postulate.

 

For many reasons, a full flying canard or ailerons on the canard isn't a particularly good idea, but "unintentional and almost uncontrollable pitching" isn't one of them.

[Len Evansic]

I stand corrected, but still think it is a bad idea. My reasoning was based on what others have told me about changing the canard configuration, and I was not aware of the elevons in the early Vari-EZE. I need to read more of the historical info out there.

 

-- Len

[Norman]

Ah Len. Thanks for the reply and interesting reading. I have to apologize. I ment elevators, not ailerons. I have dislexia and miss some of these things. I am wondering if it is best to use elevators on the canard of have the whole wing moveable. Maybe I can get some input on the appropriate question. Norm

[Len Evansic]

I wondered that before as well. I know that the Beech Starship's canards change sweep in flight, but I suspect you mean like a stabilator. I proposed this once to counter impending stalls, and was basically told that it was too much of a change to be done without extensive testing. I was also proposing a secondary fly-by-wire system to activate the moveable canard, so in hindsight, I admit that I was adding unneeded complexity.

 

Quite often the response from people much more experienced and wiser than myself is to "Build it to plans, first" and worry about modifications later. This can be frustrating and it may seem that they are trying to stifle innovation, but their concern is for the safety of the community and protecting us from innovating an untimely end.

 

-- Len

[deronjthomas]

Do you have a ling for the Beech Starship's canard? This sound interesting. I would like to know more about this.

[bwiedenbeck]

I am brand new to this forum - but I have spent a little time reviewing the Starship as well - too bad there were so few made! Way to $$$ for me to ever consider.

 

Here is a link to a couple (of many) sites:

www.starshipdiaries.com/starship.html

www.bobscherer.com/Pages/Starship.htm

 

Bob Sherer's site is impressive... but the diary looks worth the expense as well.

[Jon Matcho]

Do you have a ling for the Beech Starship's canard?

This link at the US Patent Office will give you all you wanted to know. You can order a PDF, with drawings, for $3.00.