Date   

Re: Transfer Pump "Clicking"

Corbin <c_geiser@...>
 

Thanks guys!  I’ll check for an air leak but I’m not completely sure where I’d see that.  Any tips?

Corbin

On Mar 21, 2020, at 6:49 AM, Mike Dwyer <q200pilot@...> wrote:


The facet pumps make a hell of a racket when they run dry.  Could you have an air leak somewhere that's leaking air into the pump.  Do you have a squeeze bulb in parralel?  I've had a squeeze bulb go bad and one time at high altitude the facet pump was not keeping up with my fuel needs but when I got down to 3000 feet then it was ok.  If your pump is noisy then I'd look at pulling it.  Some auto parts stores carry them.
Mike Q200 N3QP

On Fri, Mar 20, 2020, 21:10 Corbin via Groups.Io <c_geiser=icloud.com@groups.io> wrote:
Today, my transfer pump was making a clicking sound from startup to shutdown.  It seemed as though it was pumping into the header tank just fine though as fuel was passing back down through the overflow tube from header back to main.  The sound was similar to when the pump starts to run dry but maybe a bit louder.  Is this a sign that pump could be failing?  I had about 12 gallons in the main tank so it was nowhere near running dry?

Corbin Ge!ser

--

Corbin 
N33QR


--

Corbin 
N33QR


Re: Transfer Pump "Clicking"

Bruce Crain
 

I agree with Mike.  When the tank runs dry the pump gets a lot louder!  Then I start looking for a runway!
Also clean out the fuel filter.  You can not see fiberglass in the filters!
Bruce Crain


On Mar 21, 2020, at 8:32 AM, Martin Skiby <mskiby@...> wrote:

Good thought Mike.  If it’s grabbing air that would definitely cause it cuz yes they make a lot of noise pulling air.  I remember being over the desert thinking I had an hour more in the main tank than I did and hearing that pump on the dry tank!!   Quite sobering.   I added a reliable gauge to the main tank soon after!!!

Good luck Corbin.   It may just be a small leak.  Look for bubbles.

Martin

 


On Mar 21, 2020, at 4:49 AM, Mike Dwyer <q200pilot@...> wrote:


The facet pumps make a hell of a racket when they run dry.  Could you have an air leak somewhere that's leaking air into the pump.  Do you have a squeeze bulb in parralel?  I've had a squeeze bulb go bad and one time at high altitude the facet pump was not keeping up with my fuel needs but when I got down to 3000 feet then it was ok.  If your pump is noisy then I'd look at pulling it.  Some auto parts stores carry them.
Mike Q200 N3QP

On Fri, Mar 20, 2020, 21:10 Corbin via Groups.Io <c_geiser=icloud.com@groups.io> wrote:
Today, my transfer pump was making a clicking sound from startup to shutdown.  It seemed as though it was pumping into the header tank just fine though as fuel was passing back down through the overflow tube from header back to main.  The sound was similar to when the pump starts to run dry but maybe a bit louder.  Is this a sign that pump could be failing?  I had about 12 gallons in the main tank so it was nowhere near running dry?

Corbin Ge!ser

--

Corbin 
N33QR


Re: Transfer Pump "Clicking"

Martin Skiby
 

Good thought Mike.  If it’s grabbing air that would definitely cause it cuz yes they make a lot of noise pulling air.  I remember being over the desert thinking I had an hour more in the main tank than I did and hearing that pump on the dry tank!!   Quite sobering.   I added a reliable gauge to the main tank soon after!!!

Good luck Corbin.   It may just be a small leak.  Look for bubbles.

Martin

 


On Mar 21, 2020, at 4:49 AM, Mike Dwyer <q200pilot@...> wrote:


The facet pumps make a hell of a racket when they run dry.  Could you have an air leak somewhere that's leaking air into the pump.  Do you have a squeeze bulb in parralel?  I've had a squeeze bulb go bad and one time at high altitude the facet pump was not keeping up with my fuel needs but when I got down to 3000 feet then it was ok.  If your pump is noisy then I'd look at pulling it.  Some auto parts stores carry them.
Mike Q200 N3QP

On Fri, Mar 20, 2020, 21:10 Corbin via Groups.Io <c_geiser=icloud.com@groups.io> wrote:
Today, my transfer pump was making a clicking sound from startup to shutdown.  It seemed as though it was pumping into the header tank just fine though as fuel was passing back down through the overflow tube from header back to main.  The sound was similar to when the pump starts to run dry but maybe a bit louder.  Is this a sign that pump could be failing?  I had about 12 gallons in the main tank so it was nowhere near running dry?

Corbin Ge!ser

--

Corbin 
N33QR


Re: Transfer Pump "Clicking"

Mike Dwyer
 

The facet pumps make a hell of a racket when they run dry.  Could you have an air leak somewhere that's leaking air into the pump.  Do you have a squeeze bulb in parralel?  I've had a squeeze bulb go bad and one time at high altitude the facet pump was not keeping up with my fuel needs but when I got down to 3000 feet then it was ok.  If your pump is noisy then I'd look at pulling it.  Some auto parts stores carry them.
Mike Q200 N3QP

On Fri, Mar 20, 2020, 21:10 Corbin via Groups.Io <c_geiser=icloud.com@groups.io> wrote:
Today, my transfer pump was making a clicking sound from startup to shutdown.  It seemed as though it was pumping into the header tank just fine though as fuel was passing back down through the overflow tube from header back to main.  The sound was similar to when the pump starts to run dry but maybe a bit louder.  Is this a sign that pump could be failing?  I had about 12 gallons in the main tank so it was nowhere near running dry?

Corbin Ge!ser

--

Corbin 
N33QR


Re: Transfer Pump "Clicking"

Martin Skiby
 

I’m gonna agree with Jay,  if it makes you think about it then change it out.  

Martin

 


On Mar 20, 2020, at 8:17 PM, Jay Scheevel <jay@...> wrote:


Hi Corbin,
If it makes you think about it, then replace it. Not worth the worry, it won't get better on its own, and they are not that expensive. My two cents.

Cheers,
Jay

Sent from my Verizon Wireless 4G LTE DROID


"Corbin via Groups.Io" <c_geiser@...> wrote:

Mine only makes the clicking sound when the main tank gets low and the pump is running “dry”.

Corbin

> On Mar 20, 2020, at 8:24 PM, Joe Hood <joe.hood@...> wrote:
>


--
Corbin
N33QR





Re: Transfer Pump "Clicking"

Jay Scheevel
 

Hi Corbin,
If it makes you think about it, then replace it. Not worth the worry, it won't get better on its own, and they are not that expensive. My two cents.

Cheers,
Jay

Sent from my Verizon Wireless 4G LTE DROID


"Corbin via Groups.Io" <c_geiser@...> wrote:

Mine only makes the clicking sound when the main tank gets low and the pump is running “dry”.

Corbin

> On Mar 20, 2020, at 8:24 PM, Joe Hood <joe.hood@...> wrote:
>


--
Corbin
N33QR





Re: Transfer Pump "Clicking"

Corbin <c_geiser@...>
 

Mine only makes the clicking sound when the main tank gets low and the pump is running “dry”.

Corbin

On Mar 20, 2020, at 8:24 PM, Joe Hood <joe.hood@...> wrote:
--
Corbin
N33QR


Re: Transfer Pump "Clicking"

Joe Hood <joe.hood@...>
 

Is it supposed to make noise? The one in my Q2 does. Now the Citabria I'm using for a tail-wheel endorsement is quiet (and the 172 is loud).


On Fri, Mar 20, 2020 at 9:10 PM Corbin via Groups.Io <c_geiser=icloud.com@groups.io> wrote:
Today, my transfer pump was making a clicking sound from startup to shutdown.  It seemed as though it was pumping into the header tank just fine though as fuel was passing back down through the overflow tube from header back to main.  The sound was similar to when the pump starts to run dry but maybe a bit louder.  Is this a sign that pump could be failing?  I had about 12 gallons in the main tank so it was nowhere near running dry?

Corbin Ge!ser

--

Corbin 
N33QR


Transfer Pump "Clicking"

Corbin <c_geiser@...>
 

Today, my transfer pump was making a clicking sound from startup to shutdown.  It seemed as though it was pumping into the header tank just fine though as fuel was passing back down through the overflow tube from header back to main.  The sound was similar to when the pump starts to run dry but maybe a bit louder.  Is this a sign that pump could be failing?  I had about 12 gallons in the main tank so it was nowhere near running dry?

Corbin Ge!ser

--

Corbin 
N33QR


Re: Sparrow strainer stall

Jay Scheevel
 

Comparison of shape of Roncz, and LS-1 airfoils. (from Q-talk 97)

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Friday, March 20, 2020 4:30 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

Copy that David.

I wonder if the Roncz canard has the elevator top air moving in board at cruise or was it designed out?

I think Mark Shuck was working on a Roncz canard to the Quickie.  I don't know what he was planning to do with the calcs.  Would be interesting to see what he came up with and if it would work on the Quickie.  Need for speed!!

Bruce

 


---------- Original Message ----------
From: "David J. Gall" <David@...>
To: main@q-list.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Fri, 20 Mar 2020 09:06:05 -0700

Bruce,

 

The LS-1 airfoil has been a poor choice since day one, precisely because of the elevator shape that causes it to float trailing-edge up requiring sparrow strainers to counteract. And QAC knew it; it was never “working well.” In fact, it resulted in Burt coming over from RAF and trying to get them to go a different direction, resulting in the “breakup” of RAF and QAC. A MUCH better airfoil was already under development at RAF, now known as the Roncz 1145MS “new” canard airfoil for the Long-EZ. 

 

What you’re dealing with is uncharted territory since you’ve placed your sparrow strainers in a different location from “the plans,” but I would argue that even “the plans” had a less than thoroughly worked out specification for them. Nowhere has QAC ever addressed the stick-force and stick-position gradients or neutral point and CG range, or the corrections needed for airplanes that end up out of trim as a result of construction variances. These issues were thoroughly discussed in Rutan’s “Canard Pusher” newsletter but were never echoed in any QAC guidance.

 

All QAC ever addressed was ground handling, and they did it by various aerodynamic band-aids that contribute to bizarre and outright aberrant flight control positions in flight — and yet, there have been (to my knowledge) no resulting loss of control incidents. That’s NOT a testament to great aerodynamic design work, but to the cautious and judicious approach to flight testing and operations of the various builders, and this community of builders working together to corral the Mavericks before somebody hurts themselves. 

 

You’ve identified a regime in which your control forces change in an unexpected and undesirable manner. A stalled sparrow strainer is a potentially dangerous condition since the sparrow strainers are so intimately tied to the tactile and visceral kinesthetic sense we humans use to operate machinery “intuitively” when our higher brain functions are engaged in more pressing matters. In other words, in a clutch, the damn plane can unpredictably depart from expected behavior just when you really need it to be predictable. I hope you figure out how to fix this. But don’t expect that QAC ever really had it dialed in, either.

 

David J. Gall

 

On Mar 19, 2020, at 7:33 PM, Bruce Crain <jcrain2@...> wrote:

Say Jay I

think the tufts on the elevator were moving the same direction in normal cruise (from outboard to inboard) regardless of the sparrow strainer stalling or not stalling.  It could be exacerbating where the air flow goes due to the strainers moving up and being blanked by the elevator perhaps.  I except when I pull the stick and lower the strainer back to cruise pitch or lower it still takes stalling the canard to alleviate the sparrow strainer stall.  Maybe my outboard strainer is the difference between my Q and others but then I believe DFly's have outboard maybe.  Charlie can you back me up on that?  Or maybe no one else has actually pulled up and unloaded their Quickie to the extent that I have.

 

It has bothered me for a few years that the airflow on the elevator move inboard like it does.  To an aerodynamisist it means a big loss in speed doesn't it?  I am sure when the LS1 airfoil came out they had it working well.  Maybe it's just me.

Bruce Crain  

Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Thu, 19 Mar 2020 09:39:12 -0600

<mime-attachment>


Re: Sparrow strainer stall

Jay Scheevel
 

Comparison model data of Roncz versus a few other airfoils of that vintage.

 

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Friday, March 20, 2020 4:30 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

Copy that David.

I wonder if the Roncz canard has the elevator top air moving in board at cruise or was it designed out?

I think Mark Shuck was working on a Roncz canard to the Quickie.  I don't know what he was planning to do with the calcs.  Would be interesting to see what he came up with and if it would work on the Quickie.  Need for speed!!

Bruce

 


---------- Original Message ----------
From: "David J. Gall" <David@...>
To: main@q-list.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Fri, 20 Mar 2020 09:06:05 -0700

Bruce,

 

The LS-1 airfoil has been a poor choice since day one, precisely because of the elevator shape that causes it to float trailing-edge up requiring sparrow strainers to counteract. And QAC knew it; it was never “working well.” In fact, it resulted in Burt coming over from RAF and trying to get them to go a different direction, resulting in the “breakup” of RAF and QAC. A MUCH better airfoil was already under development at RAF, now known as the Roncz 1145MS “new” canard airfoil for the Long-EZ. 

 

What you’re dealing with is uncharted territory since you’ve placed your sparrow strainers in a different location from “the plans,” but I would argue that even “the plans” had a less than thoroughly worked out specification for them. Nowhere has QAC ever addressed the stick-force and stick-position gradients or neutral point and CG range, or the corrections needed for airplanes that end up out of trim as a result of construction variances. These issues were thoroughly discussed in Rutan’s “Canard Pusher” newsletter but were never echoed in any QAC guidance.

 

All QAC ever addressed was ground handling, and they did it by various aerodynamic band-aids that contribute to bizarre and outright aberrant flight control positions in flight — and yet, there have been (to my knowledge) no resulting loss of control incidents. That’s NOT a testament to great aerodynamic design work, but to the cautious and judicious approach to flight testing and operations of the various builders, and this community of builders working together to corral the Mavericks before somebody hurts themselves. 

 

You’ve identified a regime in which your control forces change in an unexpected and undesirable manner. A stalled sparrow strainer is a potentially dangerous condition since the sparrow strainers are so intimately tied to the tactile and visceral kinesthetic sense we humans use to operate machinery “intuitively” when our higher brain functions are engaged in more pressing matters. In other words, in a clutch, the damn plane can unpredictably depart from expected behavior just when you really need it to be predictable. I hope you figure out how to fix this. But don’t expect that QAC ever really had it dialed in, either.

 

David J. Gall

 

On Mar 19, 2020, at 7:33 PM, Bruce Crain <jcrain2@...> wrote:

Say Jay I

think the tufts on the elevator were moving the same direction in normal cruise (from outboard to inboard) regardless of the sparrow strainer stalling or not stalling.  It could be exacerbating where the air flow goes due to the strainers moving up and being blanked by the elevator perhaps.  I except when I pull the stick and lower the strainer back to cruise pitch or lower it still takes stalling the canard to alleviate the sparrow strainer stall.  Maybe my outboard strainer is the difference between my Q and others but then I believe DFly's have outboard maybe.  Charlie can you back me up on that?  Or maybe no one else has actually pulled up and unloaded their Quickie to the extent that I have.

 

It has bothered me for a few years that the airflow on the elevator move inboard like it does.  To an aerodynamisist it means a big loss in speed doesn't it?  I am sure when the LS1 airfoil came out they had it working well.  Maybe it's just me.

Bruce Crain  

Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Thu, 19 Mar 2020 09:39:12 -0600

<mime-attachment>


Re: Sparrow strainer stall

Bruce Crain
 

I don't  have a clue as it has been a looong time ago when I set up the strainers.  They were adjustable at first but the  extra bolt heads sticking out in the wind and also the rough texture of the unfinished stainers made the elevator ride up until I put an upside down flap on both of them to make them ride level in cruise.  When I finally glassed them into place they were more effective without the bolt heads so I sanded off enough of the upside down flap to get back cruise level.  Then I filled and sanded the strainers and again they were more effective so I had to sand off equal amounts of upside down flap on the strainers for cruise pitch.  Then lastly I finished primed and painted them and I ended up sanding all but a very small amount of those upside down flaps.  So I got back to almost plans built for level.  Then the stall showed  up when pushing over to lower the nose.
I probably have the most experience with the strainers in "Quickiedom" but then mine are a bit non standard.
 
I am almost finished with pulling the number 4 cylinder chasing an oil seep.  I looks like the through bolts can leak through the treads on many engines so I am putting an o ring into the 2 through bolts and remounting the cylinder and will let you all know how this plays out.
Stay tuned for the "Old and the restless quest for Quickie perfection"!
 
Bruce Crain 


---------- Original Message ----------
From: "One Sky Dog via Groups.Io" <Oneskydog@...>
To: main@q-list.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Fri, 20 Mar 2020 03:55:32 -0700

Bruce,

 
I found your previous description of stalling the sparrow strainers.
 
What is the angle between the lower elevator surface and the bottom of the sparrow strainer airfoil?
 
Regards,


On Mar 19, 2020, at 7:39 PM, Bruce Crain <jcrain2@...> wrote:

Thanks David, 
For a moment I thought it gave me a bit faster airspeed but the I realized that the air was pretty turbulent and I was having a hard time trimming for straight and level.  I do know that someone said "if you trim the elevator up and compensate level cruise trim with the reflexor you get more airspeed.  I cannot confirm that was the case.  And yes the zig zag did work.  Just made the airplane ride nose high for cruise.
 
Bruce

---------- Original Message ----------
From: "David J. Gall" <David@...>
To: main@q-list.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Thu, 19 Mar 2020 12:10:51 -0700

 

Bruce,
 
I don’t think the zig-zag tape “created drag” the way you describe it. To me, your description seems like the tape was doing exactly what it was supposed to be doing: keeping the airflow energized and attached. The fact that the now-attached airflow made the elevator “ride up” is exactly what one would expect from an improvement in the air flow over the top of the airfoil; instead of matching the new elevator position with reflexor, you could have accepted the “new normal” and trimmed for it. My bet is that you’ll see similar or identical results with VGs. Was the airplane slower as a result? If so, perhaps that was caused by the nose-high attitude you created when you trimmed the reflexor TE up instead of elevator TE down, and not by “added drag” from the zig-zag tape.
 
The problem with the sparrow strainer being stalled is that the little beastie is too small and/or too close to the elevator hinge line. This could be fixed in any of several ways, including making it bigger or re-contouring the elevator. 
 
I wouldn’t count the zig-zag tape as a failure — according to your description, it was eminently successful!
 
David J. Gall

On Mar 18, 2020, at 6:25 PM, Bruce Crain <jcrain2@...> wrote:

Jon, 
I tried the zig zag tape and did get the stall to go away right up the last test where I finally had all of the zig zag cleaned off.  With the zig zag the stall would not happen on the strainer but it created drag and dragged the strainer up and thus the elevator also.  The elevator would ride up a half inch or so and stay and I would reflex the ailerons up to compensate.
 
I am going to test actual vortex generators next.  Trying to make them small enough so that they don't  create drag and pull the elevator up.  So the zig zag did work but with less than great results for the trim I am used to seeing.
 
Before the next tests I am pulling a cylinder to check for a leak around a cylinder base stud or cylinder base o ring perhaps.
 
Bruce Crain


---------- Original Message ----------
From: "Jon Finley" <jd@...>
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Wed, 18 Mar 2020 11:41:07 -0700

Howdy Jay,

I recently heard a woman admit that there are "degrees of yes" - I was stunned. Of course, I was very familiar with this phenomena but had never heard the other gender actually admit to it. Now you are talking about "degrees of stalled" - please confirm your gender!! 

:-)

Seriously, I know you are correct. I also saw this in my GU canard tuft testing (moving up/forward on the airfoil). 

Bruce; I don't know what to say on your strainers. I struggled to know how to set them (and eventually gave up on them on my GU, since they weren't needed/per-plans (instead, springs take up the load, as I recall)).  I imagine you have already tried reducing their angle of attack - and noted some change in stick force?? 

Jon  

 


Re: Sparrow strainer stall

Bruce Crain
 

Copy that David.
I wonder if the Roncz canard has the elevator top air moving in board at cruise or was it designed out?
I think Mark Shuck was working on a Roncz canard to the Quickie.  I don't know what he was planning to do with the calcs.  Would be interesting to see what he came up with and if it would work on the Quickie.  Need for speed!!
Bruce
 

---------- Original Message ----------
From: "David J. Gall" <David@...>
To: main@q-list.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Fri, 20 Mar 2020 09:06:05 -0700

Bruce,
 
The LS-1 airfoil has been a poor choice since day one, precisely because of the elevator shape that causes it to float trailing-edge up requiring sparrow strainers to counteract. And QAC knew it; it was never “working well.” In fact, it resulted in Burt coming over from RAF and trying to get them to go a different direction, resulting in the “breakup” of RAF and QAC. A MUCH better airfoil was already under development at RAF, now known as the Roncz 1145MS “new” canard airfoil for the Long-EZ. 
 
What you’re dealing with is uncharted territory since you’ve placed your sparrow strainers in a different location from “the plans,” but I would argue that even “the plans” had a less than thoroughly worked out specification for them. Nowhere has QAC ever addressed the stick-force and stick-position gradients or neutral point and CG range, or the corrections needed for airplanes that end up out of trim as a result of construction variances. These issues were thoroughly discussed in Rutan’s “Canard Pusher” newsletter but were never echoed in any QAC guidance.
 
All QAC ever addressed was ground handling, and they did it by various aerodynamic band-aids that contribute to bizarre and outright aberrant flight control positions in flight — and yet, there have been (to my knowledge) no resulting loss of control incidents. That’s NOT a testament to great aerodynamic design work, but to the cautious and judicious approach to flight testing and operations of the various builders, and this community of builders working together to corral the Mavericks before somebody hurts themselves. 
 
You’ve identified a regime in which your control forces change in an unexpected and undesirable manner. A stalled sparrow strainer is a potentially dangerous condition since the sparrow strainers are so intimately tied to the tactile and visceral kinesthetic sense we humans use to operate machinery “intuitively” when our higher brain functions are engaged in more pressing matters. In other words, in a clutch, the damn plane can unpredictably depart from expected behavior just when you really need it to be predictable. I hope you figure out how to fix this. But don’t expect that QAC ever really had it dialed in, either.
 
David J. Gall

On Mar 19, 2020, at 7:33 PM, Bruce Crain <jcrain2@...> wrote:

Say Jay I
think the tufts on the elevator were moving the same direction in normal cruise (from outboard to inboard) regardless of the sparrow strainer stalling or not stalling.  It could be exacerbating where the air flow goes due to the strainers moving up and being blanked by the elevator perhaps.  I except when I pull the stick and lower the strainer back to cruise pitch or lower it still takes stalling the canard to alleviate the sparrow strainer stall.  Maybe my outboard strainer is the difference between my Q and others but then I believe DFly's have outboard maybe.  Charlie can you back me up on that?  Or maybe no one else has actually pulled up and unloaded their Quickie to the extent that I have.
 
It has bothered me for a few years that the airflow on the elevator move inboard like it does.  To an aerodynamisist it means a big loss in speed doesn't it?  I am sure when the LS1 airfoil came out they had it working well.  Maybe it's just me.
Bruce Crain  

Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Thu, 19 Mar 2020 09:39:12 -0600

<mime-attachment>


Re: Sparrow strainer stall

David J. Gall
 

Bruce,

The LS-1 airfoil has been a poor choice since day one, precisely because of the elevator shape that causes it to float trailing-edge up requiring sparrow strainers to counteract. And QAC knew it; it was never “working well.” In fact, it resulted in Burt coming over from RAF and trying to get them to go a different direction, resulting in the “breakup” of RAF and QAC. A MUCH better airfoil was already under development at RAF, now known as the Roncz 1145MS “new” canard airfoil for the Long-EZ. 

What you’re dealing with is uncharted territory since you’ve placed your sparrow strainers in a different location from “the plans,” but I would argue that even “the plans” had a less than thoroughly worked out specification for them. Nowhere has QAC ever addressed the stick-force and stick-position gradients or neutral point and CG range, or the corrections needed for airplanes that end up out of trim as a result of construction variances. These issues were thoroughly discussed in Rutan’s “Canard Pusher” newsletter but were never echoed in any QAC guidance.

All QAC ever addressed was ground handling, and they did it by various aerodynamic band-aids that contribute to bizarre and outright aberrant flight control positions in flight — and yet, there have been (to my knowledge) no resulting loss of control incidents. That’s NOT a testament to great aerodynamic design work, but to the cautious and judicious approach to flight testing and operations of the various builders, and this community of builders working together to corral the Mavericks before somebody hurts themselves. 

You’ve identified a regime in which your control forces change in an unexpected and undesirable manner. A stalled sparrow strainer is a potentially dangerous condition since the sparrow strainers are so intimately tied to the tactile and visceral kinesthetic sense we humans use to operate machinery “intuitively” when our higher brain functions are engaged in more pressing matters. In other words, in a clutch, the damn plane can unpredictably depart from expected behavior just when you really need it to be predictable. I hope you figure out how to fix this. But don’t expect that QAC ever really had it dialed in, either.

David J. Gall

On Mar 19, 2020, at 7:33 PM, Bruce Crain <jcrain2@...> wrote:


Say Jay I
think the tufts on the elevator were moving the same direction in normal cruise (from outboard to inboard) regardless of the sparrow strainer stalling or not stalling.  It could be exacerbating where the air flow goes due to the strainers moving up and being blanked by the elevator perhaps.  I except when I pull the stick and lower the strainer back to cruise pitch or lower it still takes stalling the canard to alleviate the sparrow strainer stall.  Maybe my outboard strainer is the difference between my Q and others but then I believe DFly's have outboard maybe.  Charlie can you back me up on that?  Or maybe no one else has actually pulled up and unloaded their Quickie to the extent that I have.
 
It has bothered me for a few years that the airflow on the elevator move inboard like it does.  To an aerodynamisist it means a big loss in speed doesn't it?  I am sure when the LS1 airfoil came out they had it working well.  Maybe it's just me.
Bruce Crain  

Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Thu, 19 Mar 2020 09:39:12 -0600

<mime-attachment>


Re: Sparrow strainer stall

Jay Scheevel
 

Hi Bruce,

 

If the tufts are pointing any direction other than straight back, they are caught up in the vortex within the separation bubble. The size of this bubble increases dependent on the airflow conditions. Could be that when you are in cruise the bubble is small and then when you see the “stalled strainer”, the bubble has become large enough to include the sparrow strainer.  I have superimposed some wind tunnel smoke trail snapshots on my canard at three different attack angles, so you can see the size of the bubble (where the smoke trails get jumbled). The tubuelence always there to some extent because of the pressure discontinuity at the trailing edge. The only time it goes away is on a symmetrical airfoil at zero incidence. The square edge on the trailing edge of the LS1 is an attempt to limit the size of that turbulence bubble at low AOA. It does not work very well when the elevator is deflected.

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Thursday, March 19, 2020 8:32 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall

 

Say Jay I

think the tufts on the elevator were moving the same direction in normal cruise (from outboard to inboard) regardless of the sparrow strainer stalling or not stalling.  It could be exacerbating where the air flow goes due to the strainers moving up and being blanked by the elevator perhaps.  I except when I pull the stick and lower the strainer back to cruise pitch or lower it still takes stalling the canard to alleviate the sparrow strainer stall.  Maybe my outboard strainer is the difference between my Q and others but then I believe DFly's have outboard maybe.  Charlie can you back me up on that?  Or maybe no one else has actually pulled up and unloaded their Quickie to the extent that I have.

 

It has bothered me for a few years that the airflow on the elevator move inboard like it does.  To an aerodynamisist it means a big loss in speed doesn't it?  I am sure when the LS1 airfoil came out they had it working well.  Maybe it's just me.

Bruce Crain  

Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Thu, 19 Mar 2020 09:39:12 -0600


Re: Sparrow strainer stall

One Sky Dog
 

Bruce,

I found your previous description of stalling the sparrow strainers.

What is the angle between the lower elevator surface and the bottom of the sparrow strainer airfoil?

On Mar 19, 2020, at 7:39 PM, Bruce Crain <jcrain2@...> wrote:


Thanks David, 
For a moment I thought it gave me a bit faster airspeed but the I realized that the air was pretty turbulent and I was having a hard time trimming for straight and level.  I do know that someone said "if you trim the elevator up and compensate level cruise trim with the reflexor you get more airspeed.  I cannot confirm that was the case.  And yes the zig zag did work.  Just made the airplane ride nose high for cruise.
 
Bruce

---------- Original Message ----------
From: "David J. Gall" <David@...>
To: main@q-list.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Thu, 19 Mar 2020 12:10:51 -0700

Bruce,
 
I don’t think the zig-zag tape “created drag” the way you describe it. To me, your description seems like the tape was doing exactly what it was supposed to be doing: keeping the airflow energized and attached. The fact that the now-attached airflow made the elevator “ride up” is exactly what one would expect from an improvement in the air flow over the top of the airfoil; instead of matching the new elevator position with reflexor, you could have accepted the “new normal” and trimmed for it. My bet is that you’ll see similar or identical results with VGs. Was the airplane slower as a result? If so, perhaps that was caused by the nose-high attitude you created when you trimmed the reflexor TE up instead of elevator TE down, and not by “added drag” from the zig-zag tape.
 
The problem with the sparrow strainer being stalled is that the little beastie is too small and/or too close to the elevator hinge line. This could be fixed in any of several ways, including making it bigger or re-contouring the elevator. 
 
I wouldn’t count the zig-zag tape as a failure — according to your description, it was eminently successful!
 
David J. Gall

On Mar 18, 2020, at 6:25 PM, Bruce Crain <jcrain2@...> wrote:

Jon, 
I tried the zig zag tape and did get the stall to go away right up the last test where I finally had all of the zig zag cleaned off.  With the zig zag the stall would not happen on the strainer but it created drag and dragged the strainer up and thus the elevator also.  The elevator would ride up a half inch or so and stay and I would reflex the ailerons up to compensate.
 
I am going to test actual vortex generators next.  Trying to make them small enough so that they don't  create drag and pull the elevator up.  So the zig zag did work but with less than great results for the trim I am used to seeing.
 
Before the next tests I am pulling a cylinder to check for a leak around a cylinder base stud or cylinder base o ring perhaps.
 
Bruce Crain


---------- Original Message ----------
From: "Jon Finley" <jd@...>
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Wed, 18 Mar 2020 11:41:07 -0700

Howdy Jay,

I recently heard a woman admit that there are "degrees of yes" - I was stunned. Of course, I was very familiar with this phenomena but had never heard the other gender actually admit to it. Now you are talking about "degrees of stalled" - please confirm your gender!! 

:-)

Seriously, I know you are correct. I also saw this in my GU canard tuft testing (moving up/forward on the airfoil). 

Bruce; I don't know what to say on your strainers. I struggled to know how to set them (and eventually gave up on them on my GU, since they weren't needed/per-plans (instead, springs take up the load, as I recall)).  I imagine you have already tried reducing their angle of attack - and noted some change in stick force?? 

Jon  

 


Re: Sparrow strainer stall

One Sky Dog
 

Bruce,

I have sparrow strainers outboard and added one inboard when my incidence was wrong. I do not fully understand when this is happening to your plane. Is this while you are rolling the plane? I have never rolled a plane and Dragonflies are reported to be poor rollers so I have zero experience in that attitude.

I have lost sparrow strainers in flight which would be equivalent to a fully stalled sparrow strainers in no assistance in keeping the elevators down and loaded. Without a sparrow strainer the elevators raise and the nose goes down requiring constant back pressure on the stick.

Please reiterate when this phenomenon occurs I am missing something.

On Mar 19, 2020, at 7:33 PM, Bruce Crain <jcrain2@...> wrote:

I believe DFly's have outboard maybe.  Charlie can you back me up on that?  Or maybe no one else has actually pulled up and unloaded their Quickie to the extent that I have.


Re: Sparrow strainer stall

Bruce Crain
 

Thanks David, 
For a moment I thought it gave me a bit faster airspeed but the I realized that the air was pretty turbulent and I was having a hard time trimming for straight and level.  I do know that someone said "if you trim the elevator up and compensate level cruise trim with the reflexor you get more airspeed.  I cannot confirm that was the case.  And yes the zig zag did work.  Just made the airplane ride nose high for cruise.
 
Bruce


---------- Original Message ----------
From: "David J. Gall" <David@...>
To: main@q-list.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Thu, 19 Mar 2020 12:10:51 -0700

Bruce,
 
I don’t think the zig-zag tape “created drag” the way you describe it. To me, your description seems like the tape was doing exactly what it was supposed to be doing: keeping the airflow energized and attached. The fact that the now-attached airflow made the elevator “ride up” is exactly what one would expect from an improvement in the air flow over the top of the airfoil; instead of matching the new elevator position with reflexor, you could have accepted the “new normal” and trimmed for it. My bet is that you’ll see similar or identical results with VGs. Was the airplane slower as a result? If so, perhaps that was caused by the nose-high attitude you created when you trimmed the reflexor TE up instead of elevator TE down, and not by “added drag” from the zig-zag tape.
 
The problem with the sparrow strainer being stalled is that the little beastie is too small and/or too close to the elevator hinge line. This could be fixed in any of several ways, including making it bigger or re-contouring the elevator. 
 
I wouldn’t count the zig-zag tape as a failure — according to your description, it was eminently successful!
 
David J. Gall

On Mar 18, 2020, at 6:25 PM, Bruce Crain <jcrain2@...> wrote:

Jon, 
I tried the zig zag tape and did get the stall to go away right up the last test where I finally had all of the zig zag cleaned off.  With the zig zag the stall would not happen on the strainer but it created drag and dragged the strainer up and thus the elevator also.  The elevator would ride up a half inch or so and stay and I would reflex the ailerons up to compensate.
 
I am going to test actual vortex generators next.  Trying to make them small enough so that they don't  create drag and pull the elevator up.  So the zig zag did work but with less than great results for the trim I am used to seeing.
 
Before the next tests I am pulling a cylinder to check for a leak around a cylinder base stud or cylinder base o ring perhaps.
 
Bruce Crain


---------- Original Message ----------
From: "Jon Finley" <jd@...>
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Wed, 18 Mar 2020 11:41:07 -0700

Howdy Jay,

I recently heard a woman admit that there are "degrees of yes" - I was stunned. Of course, I was very familiar with this phenomena but had never heard the other gender actually admit to it. Now you are talking about "degrees of stalled" - please confirm your gender!! 

:-)

Seriously, I know you are correct. I also saw this in my GU canard tuft testing (moving up/forward on the airfoil). 

Bruce; I don't know what to say on your strainers. I struggled to know how to set them (and eventually gave up on them on my GU, since they weren't needed/per-plans (instead, springs take up the load, as I recall)).  I imagine you have already tried reducing their angle of attack - and noted some change in stick force?? 

Jon  

 


Re: Sparrow strainer stall

Bruce Crain
 

Say Jay I
think the tufts on the elevator were moving the same direction in normal cruise (from outboard to inboard) regardless of the sparrow strainer stalling or not stalling.  It could be exacerbating where the air flow goes due to the strainers moving up and being blanked by the elevator perhaps.  I except when I pull the stick and lower the strainer back to cruise pitch or lower it still takes stalling the canard to alleviate the sparrow strainer stall.  Maybe my outboard strainer is the difference between my Q and others but then I believe DFly's have outboard maybe.  Charlie can you back me up on that?  Or maybe no one else has actually pulled up and unloaded their Quickie to the extent that I have.
 
It has bothered me for a few years that the airflow on the elevator move inboard like it does.  To an aerodynamisist it means a big loss in speed doesn't it?  I am sure when the LS1 airfoil came out they had it working well.  Maybe it's just me.
Bruce Crain  

Please note: message attached

From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: Re: [Q-List] Sparrow strainer stall
Date: Thu, 19 Mar 2020 09:39:12 -0600


Re: Sparrow strainer stall

David J. Gall
 

Dang it! Bruce, I misunderstood where you were putting the zig-zag tape. Disregard my previous post.......

On Mar 19, 2020, at 12:11 PM, David J. Gall <David@...> wrote:


Bruce,

I don’t think the zig-zag tape “created drag” the way you describe it. To me, your description seems like the tape was doing exactly what it was supposed to be doing: keeping the airflow energized and attached. The fact that the now-attached airflow made the elevator “ride up” is exactly what one would expect from an improvement in the air flow over the top of the airfoil; instead of matching the new elevator position with reflexor, you could have accepted the “new normal” and trimmed for it. My bet is that you’ll see similar or identical results with VGs. Was the airplane slower as a result? If so, perhaps that was caused by the nose-high attitude you created when you trimmed the reflexor TE up instead of elevator TE down, and not by “added drag” from the zig-zag tape.

The problem with the sparrow strainer being stalled is that the little beastie is too small and/or too close to the elevator hinge line. This could be fixed in any of several ways, including making it bigger or re-contouring the elevator. 

I wouldn’t count the zig-zag tape as a failure — according to your description, it was eminently successful!

David J. Gall

On Mar 18, 2020, at 6:25 PM, Bruce Crain <jcrain2@...> wrote:


Jon, 
I tried the zig zag tape and did get the stall to go away right up the last test where I finally had all of the zig zag cleaned off.  With the zig zag the stall would not happen on the strainer but it created drag and dragged the strainer up and thus the elevator also.  The elevator would ride up a half inch or so and stay and I would reflex the ailerons up to compensate.
 
I am going to test actual vortex generators next.  Trying to make them small enough so that they don't  create drag and pull the elevator up.  So the zig zag did work but with less than great results for the trim I am used to seeing.
 
Before the next tests I am pulling a cylinder to check for a leak around a cylinder base stud or cylinder base o ring perhaps.
 
Bruce Crain


---------- Original Message ----------
From: "Jon Finley" <jd@...>
To: main@Q-List.groups.io
Subject: Re: [Q-List] Sparrow strainer stall
Date: Wed, 18 Mar 2020 11:41:07 -0700

Howdy Jay,

I recently heard a woman admit that there are "degrees of yes" - I was stunned. Of course, I was very familiar with this phenomena but had never heard the other gender actually admit to it. Now you are talking about "degrees of stalled" - please confirm your gender!! 

:-)

Seriously, I know you are correct. I also saw this in my GU canard tuft testing (moving up/forward on the airfoil). 

Bruce; I don't know what to say on your strainers. I struggled to know how to set them (and eventually gave up on them on my GU, since they weren't needed/per-plans (instead, springs take up the load, as I recall)).  I imagine you have already tried reducing their angle of attack - and noted some change in stick force?? 

Jon