V-TAIL OR CANARD LSA/BURT RUTAN.

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CharlieTango
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Re: V-TAIL OR CANARD LSA/BURT RUTAN.

Postby CharlieTango » Tue May 07, 2013 3:11 pm

Image

PERFORMANCE
VNE 180 m.p.h.
Vc 75% Power 165 m.p.h.
Va 120 m.p.h.
Vs 48 m.p.h.
Rate of Climb 850 f.p.m.
Service Ceiling 18500 ft.
Takeoff, 50 ft. obs 1200 ft.
Landing, 50 ft. ob 2000 ft.
Range, 75% pow 500 mi.
Fuel Capacity 15.0 gal.
Wing Loading 11.4 lb./sq. ft.
Power Loading 19.2 lb/hp
G load + 4.4
G load - 2.0
WEIGHTS
Gross 1150 lb.
Payload 545 lb.
Baggage Limit 20/70 lb.

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CharlieTango
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Re: V-TAIL OR CANARD LSA/BURT RUTAN.

Postby CharlieTango » Tue May 07, 2013 3:21 pm

Image

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4-cylinder, 4-stroke aircraft engine that runs on Avgas

or

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Spacious comfort in a cockpit with conventional stick control.

This rugged, unique composite construction requires very little maintenance.



http://www.rmtaviation.com/

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Re: V-TAIL OR CANARD LSA/BURT RUTAN.

Postby drseti » Tue May 07, 2013 3:35 pm

CharlieTango wrote:High cruising speed, in excess of 250 km/h (150 Mph).


Wait a minute. That's 131 knots, which I do believe is greater than 120 -- didn't you say LSA??
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CharlieTango
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Re: V-TAIL OR CANARD LSA/BURT RUTAN.

Postby CharlieTango » Tue May 07, 2013 3:56 pm

drseti wrote:
CharlieTango wrote:High cruising speed, in excess of 250 km/h (150 Mph).


Wait a minute. That's 131 knots, which I do believe is greater than 120 -- didn't you say LSA??


The LSA Version

The LSA version of the Bateleur will be offered only with fixed under carriage and a ground adjustable propeller, to meet all of the requirements for the aircraft to be flown with a Sport Pilot License.

http://www.rmtaviation.com/Models.htm

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Re: V-TAIL OR CANARD LSA/BURT RUTAN.

Postby CharlieTango » Tue May 07, 2013 7:01 pm


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Re: V-TAIL OR CANARD LSA/BURT RUTAN.

Postby CharlieTango » Tue May 07, 2013 7:39 pm

Ok, I'm intrigued a canard LSA has merit.

I think the way to go is a plans built dragonfly, with the mains on the canard tips, and a small motor to be LSA legal.

It has its limitations but the economy would be unreal.

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Re: V-TAIL OR CANARD LSA/BURT RUTAN.

Postby tu16 » Tue May 07, 2013 9:08 pm

CharlieTango wrote:Ok, I'm intrigued a canard LSA has merit.

I think the way to go is a plans built dragonfly, with the mains on the canard tips, and a small motor to be LSA legal.

It has its limitations but the economy would be unreal.

:) Being a lazy lot I'd keep wondering why do I need to build two wings while everybody else gets away with one. I'd also have concerns on putting wheels on canard tips. Remember, one cannot make a full stall landings in this configuration. One has to just plant it on a pavement . To build a third wing and a fuse and a prop etc. after just one landing would be too much work. BTW Dragonfly I think normally is equipped with pretty small motor - VW 75hp...

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Re: V-TAIL OR CANARD LSA/BURT RUTAN.

Postby CharlieTango » Tue May 07, 2013 10:05 pm

tu16 wrote::) Being a lazy lot I'd keep wondering why do I need to build two wings while everybody else gets away with one. I'd also have concerns on putting wheels on canard tips. Remember, one cannot make a full stall landings in this configuration. One has to just plant it on a pavement . To build a third wing and a fuse and a prop etc. after just one landing would be too much work. BTW Dragonfly I think normally is equipped with pretty small motor - VW 75hp...


Its not my thread, I'm just playing along.

Do you realize you can buy a plane like this for about $11,000 and you might get 40mi/gal? So you need to fly it on at 80mph, thats how most of the people I know land their LSA anyway. :roll:

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Re: V-TAIL OR CANARD LSA/BURT RUTAN.

Postby FastEddieB » Wed May 08, 2013 6:57 am

tu16 wrote:Being a lazy lot I'd keep wondering why do I need to build two wings while everybody else gets away with one.


For the most part, does not nearly "everybody else" have two wings - typically one on the front and one on the back?

I think the logic is that the conventional arrangement is inherently inefficient. Why? With the CG ahead of the center of lift of the main wing, the horizontal stabilizer has to provide a down force. So the main wing has to lift the weight of the plane plus the tail down force*.

The logic behind a canard is that if you're going to have a second wing, it might as well share in the lifting.


*its why most planes will be faster loaded towards the rear of their CG envelope - less tail downforce = less lift needed = less induced drag. If you have a plane with adjustable seats, in really smooth air you might see an extra knot or so just by sliding your seat back. Mooney salesmen were allegedly well versed in this!
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Re: V-TAIL OR CANARD LSA/BURT RUTAN.

Postby tu16 » Thu May 09, 2013 3:45 pm

FastEddieB wrote:
tu16 wrote:Being a lazy lot I'd keep wondering why do I need to build two wings while everybody else gets away with one.


For the most part, does not nearly "everybody else" have two wings - typically one on the front and one on the back?

I think the logic is that the conventional arrangement is inherently inefficient. Why? With the CG ahead of the center of lift of the main wing, the horizontal stabilizer has to provide a down force. So the main wing has to lift the weight of the plane plus the tail down force*.

The logic behind a canard is that if you're going to have a second wing, it might as well share in the lifting.


*its why most planes will be faster loaded towards the rear of their CG envelope - less tail downforce = less lift needed = less induced drag. If you have a plane with adjustable seats, in really smooth air you might see an extra knot or so just by sliding your seat back. Mooney salesmen were allegedly well versed in this!


:) I was waiting for somebody to pick on the reference to "one wing" :) You're right - both canard and "traditional tail" configurations are "two surface" configurations. Moreover horizontal stabilizer very often always work as a lifting surface, instead of providing a "downward pressure". What I meant is an obvious difference in labor in building small control surface vs. building yet another full scale wing. Although I do admire "Dragonfly". Although it is more a biplane than canard configuration. And it did have wheels in canards in Mk1 :) Until too many pilots did a belly flop in them.

Image

I'm familiar with canard arguable "efficiency argument" and the logic of sharing the "lifting". 40mpg in light canard plane may look impressive - but Pipistrel built a plane in traditional configuration to win NASA LSA efficiency prize with 80mpg. There's plenty of inefficiencies in canard configurations and devils in the details and in the end it doesn't seem to hold any universal "efficiency" advantages. If anybody interested in gory details:
http://www.apollocanard.com/4_canard%20myths.htm
http://www.djaerotech.com/dj_askjd/dj_q ... anard.html
Last edited by tu16 on Thu May 09, 2013 7:17 pm, edited 1 time in total.

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Re: V-TAIL OR CANARD LSA/BURT RUTAN.

Postby FastEddieB » Thu May 09, 2013 5:30 pm

tu16 wrote:Moreover horizontal stabilizer very often always work as a lifting surface, instead of providing a "downward pressure".


In a conventional aircraft?

If so, when?
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Re: V-TAIL OR CANARD LSA/BURT RUTAN.

Postby tu16 » Thu May 09, 2013 6:35 pm

FastEddieB wrote:
tu16 wrote:Moreover horizontal stabilizer very often always work as a lifting surface, instead of providing a "downward pressure".


In a conventional aircraft?

If so, when?


Not to rehash this quite exciting topic here - I found the thread on the topic that maybe outright fun to read :
http://www.avcanada.ca/forums2/viewtopi ... &start=150

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Re: V-TAIL OR CANARD LSA/BURT RUTAN.

Postby zaitcev » Thu May 09, 2013 10:48 pm

FastEddieB wrote:I think the logic is that the conventional arrangement is inherently inefficient. Why? With the CG ahead of the center of lift of the main wing, the horizontal stabilizer has to provide a down force.

Not true. All that's required for the static stability is for the main wing fly at larger angle of attack than the tail. The tail may be lifting. In fact it is in most of the pemitted loadings of original V35. I heard you could easily load a 172 like that, although I did not verify it myself.

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Re: V-TAIL OR CANARD LSA/BURT RUTAN.

Postby FastEddieB » Fri May 10, 2013 5:06 am

Let me review this and get back.

I did always think, and teach, that in most of our light planes, having the CG ahead of the center of lift had to cause a nose down moment. This is where stability came from.

In order to have zero tail down force, the CG and center of lift would have to be coincident. There would be no inherent stability.

In order to have the tail contributing to lift, the CG would have to be behind the center of lift - an inherently unstable arrangement.

But as I said, let me check my "bible" and get back with some ammunition (or lack thereof),
Fast Eddie B.

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Re: V-TAIL OR CANARD LSA/BURT RUTAN.

Postby tl-3000pilot » Sat May 11, 2013 5:41 pm

I still think it would be neat to see an LSA design that incorporated the appropriate canard set-up, as well as a design that incorporated the V-Tail design, much like the V-Tail Bonanza. Just make it work and beneficial somehow.

Imagine a sleek high-wing, such as the P-2008 with a V-Tail or Canard or even both.

Imagine a sleek low-wing like Bristell with one or both of the same features as well.

Would look quite impressive imho!

If only I could draw!

My wife happens to be a Metallurgist, C.A.D. and 3-D Hard-Edge Designer, maybe I can talk her into helping me throw my image into a visible example, just for fun and entertainment of course? Then all of you engineering and aeronautical design experts can tell me everything that is so wrong about my thoughts of incorporating such features. Lol! :lol:

tl-3000pilot.


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