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Turd Ferguson

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Mar 13, 2008
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5,236
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Upper midwest in a house
I think the rain and bug contamination issues were blown out of proportion.
There were stories of loss of pitch control and instability with rain contamination.
In the real world I splattered plenty of bugs with a GU canard. Also flew in light rain once.
Never noticed any difference in control feel and only a very slight need for trim adjustment.
The story I remember was straight from the horse - Canard Pusher newsletter #43 from RAF:
CP43-P1
 

pictsidhe

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Jul 15, 2014
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8,066
Location
North Carolina
Pops has used RC servos for trim tabs. They can be manually overridden... I'd not want to touch FBW for primary flight controls...
 

Hot Wings

Grumpy Cynic
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Nov 14, 2009
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7,193
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Rocky Mountains
I think he misunderstood the true scope of the former and actually meant the latter.
Given his background I'm still kind of surprised this wasn't part of the plan from the beginning. It could be one way to loose some weight and make the production version cheaper - if he ever gets that far.
 

bmcj

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Joined
Apr 10, 2007
Messages
13,495
Location
Fresno, California
Seriously? He was actually contemplating FBW as a 'fix'?
View attachment 101632
Retrofitting an aircraft like this for FBW is like a doctor prescribing propofol for someone with light insomnia! Besides, I've yet to meet a DER or DAR who would be comfortable signing off an Airworthiness Cert for a FBW-equipped HBA. Has it even been done before? Even if designed correctly with properly written flight control laws, it only adds weight and complexity! I fly FBW equipped aircraft for a living; I know how complex they are!

[Edit]: Apparently, FBW has been done in the HBA world, but do not know when this was shot, nor can I verify if this was pure FBW or augmented mechanical:

Fly by wie for very little light aircraft?


 

cblink.007

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Jul 7, 2014
Messages
434
Location
Texas, USA
Fly by wie for very little light aircraft?


Literal FBW. Touche, my friend!

I miss those old line control birds. Couldn't afford RC, so got my start with a Cox PT-19, then to a P-51. I even learned how to maintain those little .049s; was able to break one down, piece by piece, reassemble and run it without instructions before the age of 10.

Did you all know that Cox no longer makes engines? What a darn shame. I know its a topic outside the scope of this thread, but still:

tenor (19).gif
 

Tiger Tim

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Apr 26, 2013
Messages
3,305
Location
Thunder Bay
I even learned how to maintain those little .049s; was able to break one down, piece by piece, reassemble and run it without instructions before the age of 10.
Me too!

“This is my Golden Bee .049. There are many like it but this one is mine. My Golden Bee is my best friend. It is my life. I must master it as I must master my life. Without this Golden Bee my Carl Goldberg Little Toot is useless. Without the Little Toot my Golden Bee is useless...”
 

Pops

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Jan 1, 2013
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Cox International - The world's largest Cox engine and parts supplier Yes/ No on making Cox engines. Working on scratch JR Falcon.

And for the variable incidence front plane, we all need a slap in the face and also realize why we don’t do it like that anymore. The Wright Flyer.
What happen. Last Cox .049 that I bought was $2.99. Do people really pay those prices for a new one ? My first gas engine was a Atwood .049 then a O&R, then a Forester 31, then a Fox 35, etc, etc. Also a GHQ ignition and a Rogers ignition and a Cox diesel.

I have a old model airplane friend in Pa that has a Model Airplane engine collection. I have given him dozens of my engines.
 
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Marc Zeitlin

Exalted Grand Poobah
Joined
Dec 11, 2015
Messages
696
Location
Tehachapi, CA
I think the rain and bug contamination issues were blown out of proportion.
They were not.

There were stories of loss of pitch control and instability with rain contamination.
And these stories are true. In the 2003 Airventure cup race (100th anniversary of the WB) the race flew through a gate at Aurora airport at 500 ft. AGL. It happened that there was a cloud of gnats there, so ALL the planes got extremely contaminated. Some of the canards with GU airfoils later had to declare emergencies while landing at OSH, with a couple unable to maintain IAS's below 120 KIAS in level flight. I'd say that this HUGE trim change response, and the response in rain and other contamination of numerous of my customers who also fly GU canard equipped aircraft shows that there is nothing being blown out of proportion.

In the real world I splattered plenty of bugs with a GU canard. Also flew in light rain once.
While you, personally, may not have had trim changes with contamination (some don't), as Voidhawk9 points out, it seems as though the more accurate the contours of the GU canard are with respect to the definition, the worse the trim change. So you not having much trim change response probably is an indication that your GU canard contouring is not exactly per the plans.

Never noticed any difference in control feel and only a very slight need for trim adjustment.
See above. One anecdote does not data make.
 

Marc Zeitlin

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Dec 11, 2015
Messages
696
Location
Tehachapi, CA
... I’d lean towards a reflex in the trailing edge.
If you look at the GU and Roncz airfoils used on the majority of the canard aircraft, you'll see that they both have exactly this. So you're all postulating on why pitch trim springs are used instead of reflexing, when in fact, the TE of both airfoils HAVE reflexing, and when the reflexing is not implemented correctly, the hinge moments can be too large. The pitch trim springs are there because they're zero additional drag and work well.

On most of the canard aircraft, if the pitch trim springs are removed, the airplane will self trim aerodynamically at about 125 KIAS. Slower than that will require back pressure, and faster than that will require forward pressure. There's a wide variation, however, due to builder variability in airfoil shape, etc.

... Is it just that the Venn diagram of people who believe in canards and those who believe in sparrow strainers has a near 100% overlap?
In the sense that they both exist and can be shown to exist, I "believe" in both canards and sparrow strainer trim tabs. However, the only aircraft on which they're necessary are the Q-birds, which have huge, short chord canard and elevators that provide most of the lift as well as pitch control. The VE, LE, COZY, Berkut, E-Racer, etc., do not "need" sparrow strainers, as the reflexed TE airfoils and the pitch trim springs of various types work perfectly well.
 

Marc Zeitlin

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Dec 11, 2015
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Tehachapi, CA
The Proteus had them.
I never did have a good understanding of them. I’m assuming that they are more efficient than having the full length of the elevator reflexed??
Do not assume that everything you see on a Scaled aircraft is there because it's "better" :). Sometimes, things are corrections or fixes (I hesitate to use the word "bandaid").

Having three flights in Proteus to over 50k ft, and having both taken off and landed (under strict supervision in the right seat - I'm NOT rated in the plane) the thing, I can say it handles about like my F-350 after having lost power steering and brakes, with sand in the steering box. It's HEAVY on the controls. The canard/elevator are immense and heavily loaded, and the pitch forces are huge. It needed the SS in order to make pitch forces manageable.

During one Mach Tuck event in the plane, it took idle throttle and both pilot pulling with all possible force on the yokes to slowly get the plane to raise its nose and recover from the dive.
 

BBerson

Light Plane Philosopher
HBA Supporter
Joined
Dec 16, 2007
Messages
13,563
Location
Port Townsend WA
Surface finish effects rain. I had one wing with old oxidized gelcoat and the other wing I had freshly painted with shiny Imron.
Flew under a rain cloud and almost lost lateral control. Took full left aileron to stay wings level and for a minute I thought it would crash. Rain beads up on the fresh paint and lays flat on the oxidized or sanded paint. (de-energized)
 

BJC

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Oct 7, 2013
Messages
11,554
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97FL, Florida, USA
Do not assume that everything you see on a Scaled aircraft is there because it's "better" :). Sometimes, things are corrections or fixes (I hesitate to use the word "bandaid").

Having three flights in Proteus to over 50k ft, and having both taken off and landed (under strict supervision in the right seat - I'm NOT rated in the plane) the thing, I can say it handles about like my F-350 after having lost power steering and brakes, with sand in the steering box. It's HEAVY on the controls. The canard/elevator are immense and heavily loaded, and the pitch forces are huge. It needed the SS in order to make pitch forces manageable.

During one Mach Tuck event in the plane, it took idle throttle and both pilot pulling with all possible force on the yokes to slowly get the plane to raise its nose and recover from the dive.
Sounds like “bandaid” would be an understatement.


BJC
 
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