Date   

Re: New file uploaded to main@Q-List.groups.io

Martin Skiby
 

Larry,  which plane are you referring to?

Martin

 


On Dec 20, 2019, at 11:18 PM, Larry Severson <larry2@...> wrote:



Yes, this plane could be made to spin, but it has 5 different combination s of controls and power to get out of a stall. This is a bit more than the average plane. The independent control of fore and aft flaps is only part of the features.

Also, according to X-Plane it is actually faster than the Q2 with any sized comparable engine because of having laminar flow wings fore and aft..

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Friday, December 20, 2019 5:49 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] New file uploaded to main@Q-List.groups.io

 

From a standpoint of safety the "no stall/spin" part is a great asset.  If however you hold back on the stick during the porpoise it quickly get accelerated greatly.  The oscillation becomes bigger and bigger.  Not a good thing at landing and slowing down to much.

 

Scott Swing and i were talking once and he mentioned someone should make the Quickie a light sport aircraft with different wings etc.  You certainly couldn't spin it (however someone in the past noted a guy got it into some sort of spin or wild gyration that was pretty scary.  And that's all I know about that.)  Still the new model would need some other mods to improve it.  Different motor mounts would help to isolate the engine pulses and sound on the firewall.  It would most likely be slower than the ancestry Quickies.

 

Richard Kasmarec showed a print out of a 4 place Quickie at Oshkosh this year.  Which is kind of exciting!

Lots of  new technical build availability since the inception of the original 1 seat Quickie.

You never know.  Just "Brainstorming".

Bruce 

---------- Original Message ----------
From: "main@Q-List.groups.io Notification" <main+notification@Q-List.groups.io>
To: "main@Q-List.groups.io" <main@Q-List.groups.io>
Subject: [Q-List] New file uploaded to main@Q-List.groups.io
Date: Fri, 20 Dec 2019 09:29:34 -0800

Hello,

This email message is a notification to let you know that the following files have been uploaded to the Files area of the main@Q-List.groups.io group.

Uploaded By: larry severson <larry2@...>

Description:
Create a safety LSA plane from a Q2 hull.

Cheers,
The Groups.io Team

 


Re: Bruce's tuft study on sparrow strainers

Jay Scheevel
 

I do not have the elevator trim system installed. I have been using my aileron reflexor for pitch trim since I first flew my plane a year ago. The elevator seems fully stabilized without the trim system. I think that the sparrow strainers have a significant damping effect.

Cheers,
Jay

-----Original Message-----
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Matthew Curcio
Sent: Sunday, December 22, 2019 11:57 AM
To: main@q-list.groups.io
Subject: Re: [Q-List] Bruce's tuft study on sparrow strainers

Jay, I think to evaluate this conservatively you’ll have to disconnect the pitch trim springs since those help to stabilize the system in some ways.

Matthew Curcio
419-290-3773
On Dec 22, 2019, at 10:44, Jay Scheevel <jay@...> wrote:

Thanks for the more complete explanation. I have a manual "stick" type of control on my aileron reflexor. It fits into my left hand and feels and manipulates like a second stick (absent roll control obviously). I will have to try to see if I can fly the airplane using that reflexor control for pitch and the actual stick for roll. The sparrow strainers hold the elevator pretty much in trail for most AOA's (in the event that elevator continuity was absent), so I think it may be possible to fly the airplane with reflexor and aileron input only. I will try this out at a safe altitude and let you know.

Cheers,
Jay

-----Original Message-----
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Matthew Curcio
Sent: Sunday, December 22, 2019 10:46 AM
To: main@q-list.groups.io
Subject: Re: [Q-List] Bruce's tuft study on sparrow strainers

Yes but a lot more than that. This may be common knowledge for you but I’ll explain in some detail since I think most people aren’t fully aware. Taking a step back, part 23 and part 25 both say that you cannot have any single points of failure in flight control systems that are catastrophic (airplane is a total loss and more than one fatality). Look at a 172. If a pushrod or cables breaks going to the elevator (one or both panels), you can still fly with the trim tab, if you lose aileron authority (both panels) you can take advantage of adverse yaw to maintain roll authority - the quickie can’t do either of those things. A lot of pilots are aware of this but see it as a neat trick - they don’t realize it’s actually a requirement. The FARs also state stick load limits, with time functions for failure cases (This is why most twins end up with rudder trim and roll trim to deal with control loads after an engine failure) Additionally, if a 172 loses signal to one of its elevators the pilot would have ~50% elevator authority and the associated rolling moment would easily be reacted by the ailerons.

If a quickie loses signal to one elevator (hand wavey assessment here) you’re not going to have enough roll authority to react the rolling moments for continued safe flight and landing, assuming one elevator is faired and the other is being used to control pitch attitude. Its an issue of moment arms, the elevator’s arm about the longitudinal axis is so close to the CG that they require huge authority to drive a pitching moment, hence the full span and associated high stick loads that drive the requirement for sparrow strainer (it’s a band aid) - but their arm from the cg in the lateral axis is bigger than the ailerons arm. Hence, I argue that while the q2 has mostly separate load paths going to each elevator if either one fails it’s still not likely going to be survivable. I’d be thrilled if someone can prove me wrong or point to a case where that happened and it wasn’t catastrophic. There is nothing you can do to fix it, it’s just a flaw inherent with the design. Elevators should hav a big arm from the cg in the longitudinal axis and short about the lateral axis if you want to have a stable airplane, with benign failure modes.

That said, clearly if the bearing that supports the stick falls off your in a bad spot (BTW It should have a >1” long taped gusset in the x-y plane to react the loads in x that react the pilots pitch inputs, fiberglass tapes are terrible in reacting out of plane moment), if the bolt that connects the stick to elevator pushrods fails that’s single point and based on my assessment above, all the other linkage going to each surface is single point catastrophic failure.

If this were a part 25 airplane that bolt connecting the pushrods to the stick would be hollow with a second bolt running through it, the pushrods would have a second pushrod inside, as well as the torque tubes and horns a would all have parallel, independent load paths. Part 23 airplanes don’t usually end up requiring this level of complexity and the quickie just can’t be certified due to this reason and other. Im stating all of this as fact but it’s mostly hand wavey assessment (based on my experience from a couple years of designing and evaluating flight controls to part 25 requirements) so feel free to poke holes!

Matthew Curcio
419-290-3773
On Dec 22, 2019, at 08:55, Jay Scheevel <jay@...> wrote:

Hi Matthew,

When you state the that the elevator control linkage has single points of failure, are you referring to the fact that there are independent (left-right) control arms with separate push rods returning to a single point on the stick?

Cheer,
Jay N8WQ

-----Original Message-----
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Matthew Curcio
Sent: Saturday, December 21, 2019 1:32 PM
To: main@q-list.groups.io
Subject: Re: [Q-List] Bruce's tuft study on sparrow strainers

I would be extraordinarily careful with that setup and my professional recommendation would be don’t fly that. The problem is that unless you have fully evaluated the trim loads incurred during the trim runaway throughout the entire flight envelope, that failure will likely degrade handling qualities such that it would be a catastrophic single point of failure. It’d be nice to have but I wouldnt accept the risk, if not for me for a future owner.

I was just talking about this with another engineer at work (the pitch control on the quickies is pretty terrifying). Where we ended up was that the elevator control linkage on the quickie has single points of failure that are catastrophic (obviously). They would carry a PF of 1e-6 (generic probability of failure / flight hour for any mechanical system) which is kind of stomachable but would never be allowed in a part 23 aircraft. If it’s mechanically controlled, a trimable sparrow strainer introduces another 1e-6 catastrophic single point of failure and in that regard it degrades safety. It doesn’t get rid of a single point of failure it just adds one. If you put an electric sparrow strainer on the PF is going to be appreciably worse unless you had an extremely slow actuator that could reduce the time of occurence. If there is anything more than a simple toggle switch (software) you would need an involved ver-Val test program.

If a reputable aerospace company were to do this we would consider it a land as soon as practical EP, We’d determine the stick loads allowed for continued safe flight and landing, do extensive sims to test the pilots time of response to the failure in the worst phase of flight, add some margin to that time and then ensure that the trim Is slow enough to prevent those loads from developing before the pilot responds. This is not ever the preferred approach of mitigating a catastrophic failure and there’s a few hundred families who buried loved ones last year, due to a very similar scenario, that would likely agree.

For reference Proteus has a trim-able sparrow strainer, everybody that touches the airplane is petrified of it (for good reason) and it’s the subject of a lot of conversation. Just bringing that up to say it’s a fairly well understood dilemma around here.

Matthew Curcio
419-290-3773
On Dec 21, 2019, at 11:46, charlie <ffmd@...> wrote:
Way back in the mid '80s when I was building my Q1 with the first customer LS1 airfoil. I built the sparrow Strainers on hinges and drove then with model servos.
Intention was for this to be the trim system.
Being we have not flown this plane yet I have no clue how well this would work. Seems right thought.
CharlieN














Re: Bruce's tuft study on sparrow strainers

Matthew Curcio
 

Jay, I think to evaluate this conservatively you’ll have to disconnect the pitch trim springs since those help to stabilize the system in some ways.

Matthew Curcio
419-290-3773

On Dec 22, 2019, at 10:44, Jay Scheevel <jay@...> wrote:

Thanks for the more complete explanation. I have a manual "stick" type of control on my aileron reflexor. It fits into my left hand and feels and manipulates like a second stick (absent roll control obviously). I will have to try to see if I can fly the airplane using that reflexor control for pitch and the actual stick for roll. The sparrow strainers hold the elevator pretty much in trail for most AOA's (in the event that elevator continuity was absent), so I think it may be possible to fly the airplane with reflexor and aileron input only. I will try this out at a safe altitude and let you know.

Cheers,
Jay

-----Original Message-----
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Matthew Curcio
Sent: Sunday, December 22, 2019 10:46 AM
To: main@q-list.groups.io
Subject: Re: [Q-List] Bruce's tuft study on sparrow strainers

Yes but a lot more than that. This may be common knowledge for you but I’ll explain in some detail since I think most people aren’t fully aware. Taking a step back, part 23 and part 25 both say that you cannot have any single points of failure in flight control systems that are catastrophic (airplane is a total loss and more than one fatality). Look at a 172. If a pushrod or cables breaks going to the elevator (one or both panels), you can still fly with the trim tab, if you lose aileron authority (both panels) you can take advantage of adverse yaw to maintain roll authority - the quickie can’t do either of those things. A lot of pilots are aware of this but see it as a neat trick - they don’t realize it’s actually a requirement. The FARs also state stick load limits, with time functions for failure cases (This is why most twins end up with rudder trim and roll trim to deal with control loads after an engine failure) Additionally, if a 172 loses signal to one of its elevators the pilot would have ~50% elevator authority and the associated rolling moment would easily be reacted by the ailerons.

If a quickie loses signal to one elevator (hand wavey assessment here) you’re not going to have enough roll authority to react the rolling moments for continued safe flight and landing, assuming one elevator is faired and the other is being used to control pitch attitude. Its an issue of moment arms, the elevator’s arm about the longitudinal axis is so close to the CG that they require huge authority to drive a pitching moment, hence the full span and associated high stick loads that drive the requirement for sparrow strainer (it’s a band aid) - but their arm from the cg in the lateral axis is bigger than the ailerons arm. Hence, I argue that while the q2 has mostly separate load paths going to each elevator if either one fails it’s still not likely going to be survivable. I’d be thrilled if someone can prove me wrong or point to a case where that happened and it wasn’t catastrophic. There is nothing you can do to fix it, it’s just a flaw inherent with the design. Elevators should hav a big arm from the cg in the longitudinal axis and short about the lateral axis if you want to have a stable airplane, with benign failure modes.

That said, clearly if the bearing that supports the stick falls off your in a bad spot (BTW It should have a >1” long taped gusset in the x-y plane to react the loads in x that react the pilots pitch inputs, fiberglass tapes are terrible in reacting out of plane moment), if the bolt that connects the stick to elevator pushrods fails that’s single point and based on my assessment above, all the other linkage going to each surface is single point catastrophic failure.

If this were a part 25 airplane that bolt connecting the pushrods to the stick would be hollow with a second bolt running through it, the pushrods would have a second pushrod inside, as well as the torque tubes and horns a would all have parallel, independent load paths. Part 23 airplanes don’t usually end up requiring this level of complexity and the quickie just can’t be certified due to this reason and other. Im stating all of this as fact but it’s mostly hand wavey assessment (based on my experience from a couple years of designing and evaluating flight controls to part 25 requirements) so feel free to poke holes!

Matthew Curcio
419-290-3773
On Dec 22, 2019, at 08:55, Jay Scheevel <jay@...> wrote:

Hi Matthew,

When you state the that the elevator control linkage has single points of failure, are you referring to the fact that there are independent (left-right) control arms with separate push rods returning to a single point on the stick?

Cheer,
Jay N8WQ

-----Original Message-----
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Matthew Curcio
Sent: Saturday, December 21, 2019 1:32 PM
To: main@q-list.groups.io
Subject: Re: [Q-List] Bruce's tuft study on sparrow strainers

I would be extraordinarily careful with that setup and my professional recommendation would be don’t fly that. The problem is that unless you have fully evaluated the trim loads incurred during the trim runaway throughout the entire flight envelope, that failure will likely degrade handling qualities such that it would be a catastrophic single point of failure. It’d be nice to have but I wouldnt accept the risk, if not for me for a future owner.

I was just talking about this with another engineer at work (the pitch control on the quickies is pretty terrifying). Where we ended up was that the elevator control linkage on the quickie has single points of failure that are catastrophic (obviously). They would carry a PF of 1e-6 (generic probability of failure / flight hour for any mechanical system) which is kind of stomachable but would never be allowed in a part 23 aircraft. If it’s mechanically controlled, a trimable sparrow strainer introduces another 1e-6 catastrophic single point of failure and in that regard it degrades safety. It doesn’t get rid of a single point of failure it just adds one. If you put an electric sparrow strainer on the PF is going to be appreciably worse unless you had an extremely slow actuator that could reduce the time of occurence. If there is anything more than a simple toggle switch (software) you would need an involved ver-Val test program.

If a reputable aerospace company were to do this we would consider it a land as soon as practical EP, We’d determine the stick loads allowed for continued safe flight and landing, do extensive sims to test the pilots time of response to the failure in the worst phase of flight, add some margin to that time and then ensure that the trim Is slow enough to prevent those loads from developing before the pilot responds. This is not ever the preferred approach of mitigating a catastrophic failure and there’s a few hundred families who buried loved ones last year, due to a very similar scenario, that would likely agree.

For reference Proteus has a trim-able sparrow strainer, everybody that touches the airplane is petrified of it (for good reason) and it’s the subject of a lot of conversation. Just bringing that up to say it’s a fairly well understood dilemma around here.

Matthew Curcio
419-290-3773
On Dec 21, 2019, at 11:46, charlie <ffmd@...> wrote:
Way back in the mid '80s when I was building my Q1 with the first customer LS1 airfoil. I built the sparrow Strainers on hinges and drove then with model servos.
Intention was for this to be the trim system.
Being we have not flown this plane yet I have no clue how well this would work. Seems right thought.
CharlieN














Re: Bruce's tuft study on sparrow strainers

Jay Scheevel
 

Thanks for the more complete explanation. I have a manual "stick" type of control on my aileron reflexor. It fits into my left hand and feels and manipulates like a second stick (absent roll control obviously). I will have to try to see if I can fly the airplane using that reflexor control for pitch and the actual stick for roll. The sparrow strainers hold the elevator pretty much in trail for most AOA's (in the event that elevator continuity was absent), so I think it may be possible to fly the airplane with reflexor and aileron input only. I will try this out at a safe altitude and let you know.

Cheers,
Jay

-----Original Message-----
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Matthew Curcio
Sent: Sunday, December 22, 2019 10:46 AM
To: main@q-list.groups.io
Subject: Re: [Q-List] Bruce's tuft study on sparrow strainers

Yes but a lot more than that. This may be common knowledge for you but I’ll explain in some detail since I think most people aren’t fully aware. Taking a step back, part 23 and part 25 both say that you cannot have any single points of failure in flight control systems that are catastrophic (airplane is a total loss and more than one fatality). Look at a 172. If a pushrod or cables breaks going to the elevator (one or both panels), you can still fly with the trim tab, if you lose aileron authority (both panels) you can take advantage of adverse yaw to maintain roll authority - the quickie can’t do either of those things. A lot of pilots are aware of this but see it as a neat trick - they don’t realize it’s actually a requirement. The FARs also state stick load limits, with time functions for failure cases (This is why most twins end up with rudder trim and roll trim to deal with control loads after an engine failure) Additionally, if a 172 loses signal to one of its elevators the pilot would have ~50% elevator authority and the associated rolling moment would easily be reacted by the ailerons.

If a quickie loses signal to one elevator (hand wavey assessment here) you’re not going to have enough roll authority to react the rolling moments for continued safe flight and landing, assuming one elevator is faired and the other is being used to control pitch attitude. Its an issue of moment arms, the elevator’s arm about the longitudinal axis is so close to the CG that they require huge authority to drive a pitching moment, hence the full span and associated high stick loads that drive the requirement for sparrow strainer (it’s a band aid) - but their arm from the cg in the lateral axis is bigger than the ailerons arm. Hence, I argue that while the q2 has mostly separate load paths going to each elevator if either one fails it’s still not likely going to be survivable. I’d be thrilled if someone can prove me wrong or point to a case where that happened and it wasn’t catastrophic. There is nothing you can do to fix it, it’s just a flaw inherent with the design. Elevators should hav a big arm from the cg in the longitudinal axis and short about the lateral axis if you want to have a stable airplane, with benign failure modes.

That said, clearly if the bearing that supports the stick falls off your in a bad spot (BTW It should have a >1” long taped gusset in the x-y plane to react the loads in x that react the pilots pitch inputs, fiberglass tapes are terrible in reacting out of plane moment), if the bolt that connects the stick to elevator pushrods fails that’s single point and based on my assessment above, all the other linkage going to each surface is single point catastrophic failure.

If this were a part 25 airplane that bolt connecting the pushrods to the stick would be hollow with a second bolt running through it, the pushrods would have a second pushrod inside, as well as the torque tubes and horns a would all have parallel, independent load paths. Part 23 airplanes don’t usually end up requiring this level of complexity and the quickie just can’t be certified due to this reason and other. Im stating all of this as fact but it’s mostly hand wavey assessment (based on my experience from a couple years of designing and evaluating flight controls to part 25 requirements) so feel free to poke holes!

Matthew Curcio
419-290-3773
On Dec 22, 2019, at 08:55, Jay Scheevel <jay@...> wrote:

Hi Matthew,

When you state the that the elevator control linkage has single points of failure, are you referring to the fact that there are independent (left-right) control arms with separate push rods returning to a single point on the stick?

Cheer,
Jay N8WQ

-----Original Message-----
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Matthew Curcio
Sent: Saturday, December 21, 2019 1:32 PM
To: main@q-list.groups.io
Subject: Re: [Q-List] Bruce's tuft study on sparrow strainers

I would be extraordinarily careful with that setup and my professional recommendation would be don’t fly that. The problem is that unless you have fully evaluated the trim loads incurred during the trim runaway throughout the entire flight envelope, that failure will likely degrade handling qualities such that it would be a catastrophic single point of failure. It’d be nice to have but I wouldnt accept the risk, if not for me for a future owner.

I was just talking about this with another engineer at work (the pitch control on the quickies is pretty terrifying). Where we ended up was that the elevator control linkage on the quickie has single points of failure that are catastrophic (obviously). They would carry a PF of 1e-6 (generic probability of failure / flight hour for any mechanical system) which is kind of stomachable but would never be allowed in a part 23 aircraft. If it’s mechanically controlled, a trimable sparrow strainer introduces another 1e-6 catastrophic single point of failure and in that regard it degrades safety. It doesn’t get rid of a single point of failure it just adds one. If you put an electric sparrow strainer on the PF is going to be appreciably worse unless you had an extremely slow actuator that could reduce the time of occurence. If there is anything more than a simple toggle switch (software) you would need an involved ver-Val test program.

If a reputable aerospace company were to do this we would consider it a land as soon as practical EP, We’d determine the stick loads allowed for continued safe flight and landing, do extensive sims to test the pilots time of response to the failure in the worst phase of flight, add some margin to that time and then ensure that the trim Is slow enough to prevent those loads from developing before the pilot responds. This is not ever the preferred approach of mitigating a catastrophic failure and there’s a few hundred families who buried loved ones last year, due to a very similar scenario, that would likely agree.

For reference Proteus has a trim-able sparrow strainer, everybody that touches the airplane is petrified of it (for good reason) and it’s the subject of a lot of conversation. Just bringing that up to say it’s a fairly well understood dilemma around here.

Matthew Curcio
419-290-3773
On Dec 21, 2019, at 11:46, charlie <ffmd@...> wrote:

Way back in the mid '80s when I was building my Q1 with the first customer LS1 airfoil. I built the sparrow Strainers on hinges and drove then with model servos.
Intention was for this to be the trim system.
Being we have not flown this plane yet I have no clue how well this would work. Seems right thought.
CharlieN









Re: Bruce's tuft study on sparrow strainers

David J. Gall
 

Matthew,

Thank you for your significant contributions to this discussion, they are much appreciated!


David J. Gall

-----Original Message-----
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Matthew Curcio
Sent: Saturday, December 21, 2019 12:32 PM
To: main@q-list.groups.io
Subject: Re: [Q-List] Bruce's tuft study on sparrow strainers

I would be extraordinarily careful with that setup and my professional recommendation would be don’t fly that. The problem is that unless you have fully evaluated the trim loads incurred during the trim runaway throughout the entire flight envelope, that failure will likely degrade handling qualities such that it would be a catastrophic single point of failure. It’d be nice to have but I wouldnt accept the risk, if not for me for a future owner.

I was just talking about this with another engineer at work (the pitch control on the quickies is pretty terrifying). Where we ended up was that the elevator control linkage on the quickie has single points of failure that are catastrophic (obviously). They would carry a PF of 1e-6 (generic probability of failure / flight hour for any mechanical system) which is kind of stomachable but would never be allowed in a part 23 aircraft. If it’s mechanically controlled, a trimable sparrow strainer introduces another 1e-6 catastrophic single point of failure and in that regard it degrades safety. It doesn’t get rid of a single point of failure it just adds one. If you put an electric sparrow strainer on the PF is going to be appreciably worse unless you had an extremely slow actuator that could reduce the time of occurence. If there is anything more than a simple toggle switch (software) you would need an involved ver-Val test program.

If a reputable aerospace company were to do this we would consider it a land as soon as practical EP, We’d determine the stick loads allowed for continued safe flight and landing, do extensive sims to test the pilots time of response to the failure in the worst phase of flight, add some margin to that time and then ensure that the trim Is slow enough to prevent those loads from developing before the pilot responds. This is not ever the preferred approach of mitigating a catastrophic failure and there’s a few hundred families who buried loved ones last year, due to a very similar scenario, that would likely agree.

For reference Proteus has a trim-able sparrow strainer, everybody that touches the airplane is petrified of it (for good reason) and it’s the subject of a lot of conversation. Just bringing that up to say it’s a fairly well understood dilemma around here.

Matthew Curcio
419-290-3773
On Dec 21, 2019, at 11:46, charlie <ffmd@...> wrote:

Way back in the mid '80s when I was building my Q1 with the first customer LS1 airfoil. I built the sparrow Strainers on hinges and drove then with model servos.
Intention was for this to be the trim system.
Being we have not flown this plane yet I have no clue how well this would work. Seems right thought.
CharlieN




Re: Bruce's tuft study on sparrow strainers

Matthew Curcio
 

Yes but a lot more than that. This may be common knowledge for you but I’ll explain in some detail since I think most people aren’t fully aware. Taking a step back, part 23 and part 25 both say that you cannot have any single points of failure in flight control systems that are catastrophic (airplane is a total loss and more than one fatality). Look at a 172. If a pushrod or cables breaks going to the elevator (one or both panels), you can still fly with the trim tab, if you lose aileron authority (both panels) you can take advantage of adverse yaw to maintain roll authority - the quickie can’t do either of those things. A lot of pilots are aware of this but see it as a neat trick - they don’t realize it’s actually a requirement. The FARs also state stick load limits, with time functions for failure cases (This is why most twins end up with rudder trim and roll trim to deal with control loads after an engine failure) Additionally, if a 172 loses signal to one of its elevators the pilot would have ~50% elevator authority and the associated rolling moment would easily be reacted by the ailerons.

If a quickie loses signal to one elevator (hand wavey assessment here) you’re not going to have enough roll authority to react the rolling moments for continued safe flight and landing, assuming one elevator is faired and the other is being used to control pitch attitude. Its an issue of moment arms, the elevator’s arm about the longitudinal axis is so close to the CG that they require huge authority to drive a pitching moment, hence the full span and associated high stick loads that drive the requirement for sparrow strainer (it’s a band aid) - but their arm from the cg in the lateral axis is bigger than the ailerons arm. Hence, I argue that while the q2 has mostly separate load paths going to each elevator if either one fails it’s still not likely going to be survivable. I’d be thrilled if someone can prove me wrong or point to a case where that happened and it wasn’t catastrophic. There is nothing you can do to fix it, it’s just a flaw inherent with the design. Elevators should hav a big arm from the cg in the longitudinal axis and short about the lateral axis if you want to have a stable airplane, with benign failure modes.

That said, clearly if the bearing that supports the stick falls off your in a bad spot (BTW It should have a >1” long taped gusset in the x-y plane to react the loads in x that react the pilots pitch inputs, fiberglass tapes are terrible in reacting out of plane moment), if the bolt that connects the stick to elevator pushrods fails that’s single point and based on my assessment above, all the other linkage going to each surface is single point catastrophic failure.

If this were a part 25 airplane that bolt connecting the pushrods to the stick would be hollow with a second bolt running through it, the pushrods would have a second pushrod inside, as well as the torque tubes and horns a would all have parallel, independent load paths. Part 23 airplanes don’t usually end up requiring this level of complexity and the quickie just can’t be certified due to this reason and other. Im stating all of this as fact but it’s mostly hand wavey assessment (based on my experience from a couple years of designing and evaluating flight controls to part 25 requirements) so feel free to poke holes!

Matthew Curcio
419-290-3773

On Dec 22, 2019, at 08:55, Jay Scheevel <jay@...> wrote:

Hi Matthew,

When you state the that the elevator control linkage has single points of failure, are you referring to the fact that there are independent (left-right) control arms with separate push rods returning to a single point on the stick?

Cheer,
Jay N8WQ

-----Original Message-----
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Matthew Curcio
Sent: Saturday, December 21, 2019 1:32 PM
To: main@q-list.groups.io
Subject: Re: [Q-List] Bruce's tuft study on sparrow strainers

I would be extraordinarily careful with that setup and my professional recommendation would be don’t fly that. The problem is that unless you have fully evaluated the trim loads incurred during the trim runaway throughout the entire flight envelope, that failure will likely degrade handling qualities such that it would be a catastrophic single point of failure. It’d be nice to have but I wouldnt accept the risk, if not for me for a future owner.

I was just talking about this with another engineer at work (the pitch control on the quickies is pretty terrifying). Where we ended up was that the elevator control linkage on the quickie has single points of failure that are catastrophic (obviously). They would carry a PF of 1e-6 (generic probability of failure / flight hour for any mechanical system) which is kind of stomachable but would never be allowed in a part 23 aircraft. If it’s mechanically controlled, a trimable sparrow strainer introduces another 1e-6 catastrophic single point of failure and in that regard it degrades safety. It doesn’t get rid of a single point of failure it just adds one. If you put an electric sparrow strainer on the PF is going to be appreciably worse unless you had an extremely slow actuator that could reduce the time of occurence. If there is anything more than a simple toggle switch (software) you would need an involved ver-Val test program.

If a reputable aerospace company were to do this we would consider it a land as soon as practical EP, We’d determine the stick loads allowed for continued safe flight and landing, do extensive sims to test the pilots time of response to the failure in the worst phase of flight, add some margin to that time and then ensure that the trim Is slow enough to prevent those loads from developing before the pilot responds. This is not ever the preferred approach of mitigating a catastrophic failure and there’s a few hundred families who buried loved ones last year, due to a very similar scenario, that would likely agree.

For reference Proteus has a trim-able sparrow strainer, everybody that touches the airplane is petrified of it (for good reason) and it’s the subject of a lot of conversation. Just bringing that up to say it’s a fairly well understood dilemma around here.

Matthew Curcio
419-290-3773
On Dec 21, 2019, at 11:46, charlie <ffmd@...> wrote:

Way back in the mid '80s when I was building my Q1 with the first customer LS1 airfoil. I built the sparrow Strainers on hinges and drove then with model servos.
Intention was for this to be the trim system.
Being we have not flown this plane yet I have no clue how well this would work. Seems right thought.
CharlieN









Re: Bruce's tuft study on sparrow strainers

Jay Scheevel
 

Hi Matthew,

When you state the that the elevator control linkage has single points of failure, are you referring to the fact that there are independent (left-right) control arms with separate push rods returning to a single point on the stick?

Cheer,
Jay N8WQ

-----Original Message-----
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Matthew Curcio
Sent: Saturday, December 21, 2019 1:32 PM
To: main@q-list.groups.io
Subject: Re: [Q-List] Bruce's tuft study on sparrow strainers

I would be extraordinarily careful with that setup and my professional recommendation would be don’t fly that. The problem is that unless you have fully evaluated the trim loads incurred during the trim runaway throughout the entire flight envelope, that failure will likely degrade handling qualities such that it would be a catastrophic single point of failure. It’d be nice to have but I wouldnt accept the risk, if not for me for a future owner.

I was just talking about this with another engineer at work (the pitch control on the quickies is pretty terrifying). Where we ended up was that the elevator control linkage on the quickie has single points of failure that are catastrophic (obviously). They would carry a PF of 1e-6 (generic probability of failure / flight hour for any mechanical system) which is kind of stomachable but would never be allowed in a part 23 aircraft. If it’s mechanically controlled, a trimable sparrow strainer introduces another 1e-6 catastrophic single point of failure and in that regard it degrades safety. It doesn’t get rid of a single point of failure it just adds one. If you put an electric sparrow strainer on the PF is going to be appreciably worse unless you had an extremely slow actuator that could reduce the time of occurence. If there is anything more than a simple toggle switch (software) you would need an involved ver-Val test program.

If a reputable aerospace company were to do this we would consider it a land as soon as practical EP, We’d determine the stick loads allowed for continued safe flight and landing, do extensive sims to test the pilots time of response to the failure in the worst phase of flight, add some margin to that time and then ensure that the trim Is slow enough to prevent those loads from developing before the pilot responds. This is not ever the preferred approach of mitigating a catastrophic failure and there’s a few hundred families who buried loved ones last year, due to a very similar scenario, that would likely agree.

For reference Proteus has a trim-able sparrow strainer, everybody that touches the airplane is petrified of it (for good reason) and it’s the subject of a lot of conversation. Just bringing that up to say it’s a fairly well understood dilemma around here.

Matthew Curcio
419-290-3773
On Dec 21, 2019, at 11:46, charlie <ffmd@...> wrote:

Way back in the mid '80s when I was building my Q1 with the first customer LS1 airfoil. I built the sparrow Strainers on hinges and drove then with model servos.
Intention was for this to be the trim system.
Being we have not flown this plane yet I have no clue how well this would work. Seems right thought.
CharlieN




Re: Power trim on sparrow strainers

charlie
 

At 08:31 PM 12/21/2019 +0000, you wrote:
I would be extraordinarily careful with that setup and my professional recommendation would be dont fly that.
There are many good reasons we chose not to fly this plane.
Thank you Matt,

CharlieN


Re: Bruce's tuft study on sparrow strainers

Matthew Curcio
 

I would be extraordinarily careful with that setup and my professional recommendation would be don’t fly that. The problem is that unless you have fully evaluated the trim loads incurred during the trim runaway throughout the entire flight envelope, that failure will likely degrade handling qualities such that it would be a catastrophic single point of failure. It’d be nice to have but I wouldnt accept the risk, if not for me for a future owner.

I was just talking about this with another engineer at work (the pitch control on the quickies is pretty terrifying). Where we ended up was that the elevator control linkage on the quickie has single points of failure that are catastrophic (obviously). They would carry a PF of 1e-6 (generic probability of failure / flight hour for any mechanical system) which is kind of stomachable but would never be allowed in a part 23 aircraft. If it’s mechanically controlled, a trimable sparrow strainer introduces another 1e-6 catastrophic single point of failure and in that regard it degrades safety. It doesn’t get rid of a single point of failure it just adds one. If you put an electric sparrow strainer on the PF is going to be appreciably worse unless you had an extremely slow actuator that could reduce the time of occurence. If there is anything more than a simple toggle switch (software) you would need an involved ver-Val test program.

If a reputable aerospace company were to do this we would consider it a land as soon as practical EP, We’d determine the stick loads allowed for continued safe flight and landing, do extensive sims to test the pilots time of response to the failure in the worst phase of flight, add some margin to that time and then ensure that the trim Is slow enough to prevent those loads from developing before the pilot responds. This is not ever the preferred approach of mitigating a catastrophic failure and there’s a few hundred families who buried loved ones last year, due to a very similar scenario, that would likely agree.

For reference Proteus has a trim-able sparrow strainer, everybody that touches the airplane is petrified of it (for good reason) and it’s the subject of a lot of conversation. Just bringing that up to say it’s a fairly well understood dilemma around here.

Matthew Curcio
419-290-3773

On Dec 21, 2019, at 11:46, charlie <ffmd@...> wrote:

Way back in the mid '80s when I was building my Q1 with the first customer LS1 airfoil. I built the sparrow Strainers on hinges and drove then with model servos.
Intention was for this to be the trim system.
Being we have not flown this plane yet I have no clue how well this would work. Seems right thought.
CharlieN




Re: New file uploaded to main@Q-List.groups.io

Larry Severson
 

Yes, this plane could be made to spin, but it has 5 different combination s of controls and power to get out of a stall. This is a bit more than the average plane. The independent control of fore and aft flaps is only part of the features.

Also, according to X-Plane it is actually faster than the Q2 with any sized comparable engine because of having laminar flow wings fore and aft..

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Friday, December 20, 2019 5:49 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] New file uploaded to main@Q-List.groups.io

 

From a standpoint of safety the "no stall/spin" part is a great asset.  If however you hold back on the stick during the porpoise it quickly get accelerated greatly.  The oscillation becomes bigger and bigger.  Not a good thing at landing and slowing down to much.

 

Scott Swing and i were talking once and he mentioned someone should make the Quickie a light sport aircraft with different wings etc.  You certainly couldn't spin it (however someone in the past noted a guy got it into some sort of spin or wild gyration that was pretty scary.  And that's all I know about that.)  Still the new model would need some other mods to improve it.  Different motor mounts would help to isolate the engine pulses and sound on the firewall.  It would most likely be slower than the ancestry Quickies.

 

Richard Kasmarec showed a print out of a 4 place Quickie at Oshkosh this year.  Which is kind of exciting!

Lots of  new technical build availability since the inception of the original 1 seat Quickie.

You never know.  Just "Brainstorming".

Bruce 

---------- Original Message ----------
From: "main@Q-List.groups.io Notification" <main+notification@Q-List.groups.io>
To: "main@Q-List.groups.io" <main@Q-List.groups.io>
Subject: [Q-List] New file uploaded to main@Q-List.groups.io
Date: Fri, 20 Dec 2019 09:29:34 -0800

Hello,

This email message is a notification to let you know that the following files have been uploaded to the Files area of the main@Q-List.groups.io group.

Uploaded By: larry severson <larry2@...>

Description:
Create a safety LSA plane from a Q2 hull.

Cheers,
The Groups.io Team

 


Re: Bruce's tuft study on sparrow strainers

charlie
 

Way back in the mid '80s when I was building my Q1 with the first customer LS1 airfoil. I built the sparrow Strainers on hinges and drove then with model servos.
Intention was for this to be the trim system.
Being we have not flown this plane yet I have no clue how well this would work. Seems right thought.
CharlieN


Re: New file uploaded to main@Q-List.groups.io

Bruce Crain
 

From a standpoint of safety the "no stall/spin" part is a great asset.  If however you hold back on the stick during the porpoise it quickly get accelerated greatly.  The oscillation becomes bigger and bigger.  Not a good thing at landing and slowing down to much.
 
Scott Swing and i were talking once and he mentioned someone should make the Quickie a light sport aircraft with different wings etc.  You certainly couldn't spin it (however someone in the past noted a guy got it into some sort of spin or wild gyration that was pretty scary.  And that's all I know about that.)  Still the new model would need some other mods to improve it.  Different motor mounts would help to isolate the engine pulses and sound on the firewall.  It would most likely be slower than the ancestry Quickies.
 
Richard Kasmarec showed a print out of a 4 place Quickie at Oshkosh this year.  Which is kind of exciting!
Lots of  new technical build availability since the inception of the original 1 seat Quickie.
You never know.  Just "Brainstorming".
Bruce 


---------- Original Message ----------
From: "main@Q-List.groups.io Notification" <main+notification@Q-List.groups.io>
To: "main@Q-List.groups.io" <main@Q-List.groups.io>
Subject: [Q-List] New file uploaded to main@Q-List.groups.io
Date: Fri, 20 Dec 2019 09:29:34 -0800

Hello,

This email message is a notification to let you know that the following files have been uploaded to the Files area of the main@Q-List.groups.io group.

Uploaded By: larry severson <larry2@...>

Description:
Create a safety LSA plane from a Q2 hull.

Cheers,
The Groups.io Team




New file uploaded to main@Q-List.groups.io

main@Q-List.groups.io Notification <main+notification@...>
 

Hello,

This email message is a notification to let you know that the following files have been uploaded to the Files area of the main@Q-List.groups.io group.

Uploaded By: larry severson <larry2@...>

Description:
Create a safety LSA plane from a Q2 hull.

Cheers,
The Groups.io Team


Re: Safety Plane

Sam Hoskins
 

This would be an appropriate topic for the Q-Performance list, which is right here: https://q-list.groups.io/g/Q-Performance/


Safety Plane

Larry Severson
 

For anyone who wishes to see how a Q2 hull can be turned into a light sport safety plane, please contact me directly. The information is placed in a fairly long PDF telling how and why it works. This was a submittal to the EAA contest for designs to prevent loss of control.

 

Larry Severson

18242 Peters Ct

Fountain Valley, CA  92708

(714) 968-9852

Larry2@...

 

The solution to a problem simply works,

But the correct solution works simply.

 


Re: Bruce's tuft study on sparrow strainers

Bruce Crain
 

Not sure they would work on tape very well.  Shoulda coulda woulda.  I already ordered the tape on line.  Thanks Michael!
Bruce


---------- Original Message ----------
From: "Michael" <dunningme@...>
To: main@Q-List.groups.io
Subject: Re: [Q-List] Bruce's tuft study on sparrow strainers
Date: Wed, 18 Dec 2019 18:09:04 -0800

If you're in a hurry, Walmart sells turbulator tape scissors in the craft aisle; seems they think that they're "pinking shears" for some reason 😉

https://www.walmart.com/ip/Fabric-Stainless-Steel-Dressmaking-Pinking-Shears-Craft-Zig-Zag-Cut-Scissors/846245971

--
-MD
#2827 (still thinking about planning on visualizing how to finish building)




Re: Bruce's tuft study on sparrow strainers

Michael Dunning
 

If you're in a hurry, Walmart sells turbulator tape scissors in the craft aisle; seems they think that they're "pinking shears" for some reason 😉

https://www.walmart.com/ip/Fabric-Stainless-Steel-Dressmaking-Pinking-Shears-Craft-Zig-Zag-Cut-Scissors/846245971

--
-MD
#2827 (still thinking about planning on visualizing how to finish building)


Re: Bruce's tuft study on sparrow strainers

Bruce Crain
 

I changed my mind on applying the Vortex Generators for now in leu of trying the zig zag turbulator tape as Scott Swing offered.  I like to approach things slowly and if I can get the zig zag to work it seems that there would be less drag on the sparrow strainers.  Will be a  few days before they are delivered so stay tuned for data.
Bruce



Re: Bruce's tuft study on sparrow strainers

Bruce Crain
 

This reminds me of something Scott Swing and I conversed about.  Scott said someone flew the LS1 without a sparrow strainer because the absence of it created less drag for a race he had entered.  Huge stick pressure but at higher airspeed the pressure (I think) was less because of more lift on the canard.  (could have misunderstood Scott on this).
So the higher the Mach number the less forward pressure on the stick.  regular_smile
Bruce

---------- Original Message ----------
From: "Jay Scheevel" <jay@...>
To: <main@Q-List.groups.io>
Subject: [Q-List] Bruce's tuft study on sparrow strainers
Date: Mon, 16 Dec 2019 09:09:58 -0700

Thanks for the cool tuft study data, Bruce. My nerdiness must be rubbing off on you, or maybe you are just retired and want something time consuming to do.

 

Seriously, That is an interesting observation. Ideally, you would like your “trim” surfaces, such as the sparrow strainer to be well behaved under all flight conditions, but you have demonstrated that this is not the case. The sparrow strainer flies at a high AOA (negative) all the time, so as to apply a large load to the trailing edge of the elevator, push it into an accelerated condition and boom, you get it to stall. The need for them is entirely the because the aft-1/3 of the LS-1 airfoil has a significant camber on the underside. This camber is by design yielding favorable characteristics when incorporated on a non-articulated airfoil, but when you incorporate an articulated trailing edge (elevator), then the asymmetric force becomes torque on the torque tube and stick deflection instead of into a forward pitching component applied to the rigid wing structure. By countering this effect with the sparrow strainer you actually loose some of the positive characteristics of the pitching moment, and you add a lot of drag. If you could manage it as a pilot, and this is not recommended, the LS-1 would fly better and be more efficient if you could hold the elevator neutral with the stick. But this would require always be pulling lots of aft stick-force. The stick force would be very large in full cruise, and you would never find a hands off condition. It gives you an appreciation for the force that the sparrow strainer supports are experiencing constantly in flight, and why one might potentially depart the aircraft….requiring above average flying skills to recover.

 

I have modeled the forces on the LS-1 elevator and have also designed a modified LS-1 airfoil with the rear portion of the camber removed, where the forces on the redesigned elevator are balanced, (so the sparrow strainer would not be required). I have thought that sometime I would like to build a new set of these redesigned elevators and put them on my plane, but I am just getting comfortable flying with the plans design. On the redesigned airfoil, the lift profile and polars are essentially identical to the LS-1, but what is the big unknown is how the redesigned elevator would impact that stall behavior. Small changes at the trailing edge can be quite impactful on stall, and my modeling method cannot model the complexity of airflow at stall.

 

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Sunday, December 15, 2019 9:32 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Yahoo! Groups Shuck Airfoil

 

Hi Jay!

Not sure I really care to know.  Either way I will still be aviating in both and won't put any more sound insulation in either one.  (more weight)

 

On a side note I have been doing some tuft testing which might be more informational.  I have found out that if I pull up the nose and then unload it by pushing forward on the stick my sparrow strainers are stalling on the bottom side.  My TriQ will not recover in most instances until I stall out or slow down the airspeed a bunch so that I can pull the stick enough for the strainers to reattach the air underneath them.  I just received some vortex generators to put on the bottom of the strainers to do more testing and will hopefully have them in place this week to test.

 

I have noticed in the past that when I do an aileron roll this happens.  I have been all though the elevators and ailerons to make sure they were tight and they now are very solid.  So then I thought that maybe the wingtip vortices were coming up from the canard and rolling down on the main wing.  That never really looked like a good theory.  So I installed yarn tufts to see just what was going on.  When I flew it started to dawn on me that the elevator was coming up every time I experienced the phenomenon.  So I had a good idea that something much simpler was happening and it kept pointing to the sparrow strainer.  After talking with Paul Fisher, Jerry Marstall, Sammy Hoskins, and even Scott Swing at Velocity I decided we were looking at a stall.  Sure enough when I went up with the tufts in place on the canard and the top and bottom of the sparrow strainers I thought "what if I just pull up and then push forward on the stick could I replicate the problem".  When I pulled up and then unloaded the canard by pushing over the sparrow strainers held for a bit and then they relaxed to stick forward an inch or so.  I looked out and saw the elevators up about and inch or so and videoed the tufts on the bottom of the strainer disappear and the tufts on the top tufts wrap around the back of the strainer and disappear forward under the strainer!  I spoke with Paul, Jerry and Scott again and Scott was freaked but agreed that was what is happening.

 

Bingo!  Now I have to fix it so that is where the vortex generator come in.  The strainers are a really sensitive trim from dealing with them in the past plus I have them mounted half way outboard on the elevator.  I also have 1.2 degrees incidence up on the canard and .8 degrees up on the main wing so we are talking apples to oranges.

 

Sure I could just fly the Q and not go negative on the elevator enough to stall them but I like to do aileron rolls when I am board. I believe you and I experienced the stall when you were getting time in my Q before your first flight.  So we educate and experiment and come out improving the species. 

---------- Original Message ----------
From: "Jay Scheevel" <jay@...>
To: main@Q-List.groups.io
Subject: Re: [Q-List] Yahoo! Groups Shuck Airfoil
Date: Sun, 15 Dec 2019 19:53:06 -0700

Hi Bruce,

 

If you have an iPhone it has an app available that measures abient noise level. You could give that a try.

 

Cheers,

Jay

 

Sent from my Verizon Wireless 4G LTE DROID



Bruce Crain <jcrain2@...> wrote:

I have not noticed which one is quieter.  Will try to do that in the future.  Trouble is remembering how loud the other plane is between switches.

I will tell Charlie hello for you Dr Mike!

Bruce

---------- Original Message ----------
From: "Mike Shuck via Groups.Io" <mikeshuck2001@...>
To: "main@Q-List.groups.io" <main@Q-List.groups.io>
Subject: Re: [Q-List] Yahoo! Groups Shuck Airfoil
Date: Mon, 16 Dec 2019 01:37:25 +0000 (UTC)

Hi Mike, 

 

My RV6A is noisy. I have a Clark headset modified for active noise reduction but my new Zulu 3 is quieter. I have a Lycoming O-320 E2D 150 with a metal Sensinich prop. I have problem believing a Quickie 200 is quieter.

 

Mike

 

 

On Sun, Dec 15, 2019 at 7:33 PM, Mike Dwyer

<q200pilot@...> wrote:

I flew in a RV4 recently and I think the inside cockpit of the RV is a lot noisier than a Q200.  I'd expect the fiberglass sandwich to dampen some noise.  

Any other opinions?

Fly Safe,

Mike Dwyer

 

YouTube Videos: https://goo.gl/yKEHfK

Q200 Website: http://goo.gl/V8IrJF

 

On Sun, Dec 15, 2019 at 8:14 PM Bruce Crain <jcrain2@...> wrote:

Sweet!  Hope you design a mach .5 airfoil for the Quickie guys  Wouldn't that be sweet!  

I still have my TriQ 200 but I went over to the "Dark Side" when my hanger mate Charlie Calivas sold me his RV 6 for a song and a dance and then proceeded to help me rebuild the engine!  My son Jake calls me "2 planes Crain"!  
Have a Merry Christmas!

Bruce and Honeylamb Crain
---------- Original Message ----------
From: "Mike Shuck via Groups.Io" <mikeshuck2001=yahoo.com@groups.io>
To: "main@Q-List.groups.io" <main@Q-List.groups.io>
Subject: Re: [Q-List] Yahoo! Groups Shuck Airfoil
Date: Sun, 15 Dec 2019 04:06:52 +0000 (UTC)

Bruce!

Good to hear from you as well. Things are great in Wichita. I'm still designing GA airfoils and flying my  RV6A and Cessna 120. I went through Emporia two weeks ago and it reminded me of when you, your son, and I got weathered in coming back from the Quickie fly-in at Ottawa. 

 

Great hearing from you! My thanks to the Q-List group for letting me "announce" our moving Shuck Airfoil from Yahoo! Groups to Groups.io !

 

Best wishes!

Mike Shuck

Wichita, KS

 

 

 

 

On Sat, Dec 14, 2019 at 9:44 PM, Bruce Crain

<jcrain2@...> wrote:

Good to hear from you again Dr Shuck!  How are things in Wichita?

Bruce Crain

---------- Original Message ----------
From: "Mike Shuck via Groups.Io" <mikeshuck2001=yahoo.com@groups.io>
To: "main@Q-List.groups.io" <main@Q-List.groups.io>
Subject: [Q-List] Yahoo! Groups Shuck Airfoil
Date: Sun, 15 Dec 2019 00:24:29 +0000 (UTC)

Just to let you know I am in process of moving the former Yahoo! Groups Shuck Airfoil to:

 

 

I was late getting the mailing list moved over so I would be very thankful if you would post this as many

of the Shuck Airfoil group at Yahoo! Groups also were members of Q-List.

 

Many thanks!

 

Mike Shuck

Moderator of the former Yahoo! Groups Shuck Airfoil

 

 

 

 

 

 

 

 

 



Re: Bruce's tuft study on sparrow strainers

David J. Gall
 

Jay,

 

The hinge pin on the Roncz canard elevator is not concentric with the elevator torque tube. It is approximately 0.1” from the inner surface of the torque tube at the extreme bottom of the tube, much closer to the lower surface of the elevator than depicted in your initial image. Those hot wire templates look legit, though I wouldn’t trust their dimensional accuracy enough to build anything from them….

 

David J. Gall

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Jay Scheevel
Sent: Monday, December 16, 2019 4:19 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Bruce's tuft study on sparrow strainers

 

From that most reliable of sources, “the internet” 😊

 

http://www.angelfire.com/on/dragonflyaircraft/airfoils.html

 

Look about midway down the page.

 

 

I think the elevator hinge location is accurate, at least according to these hotwire templates from the Canard Zone Forums

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of David J. Gall
Sent: Monday, December 16, 2019 5:04 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Bruce's tuft study on sparrow strainers

 

Jay,

 

P.S.

 

  1. Where’d you find a picture of a Roncz R1145MS with a powered trim tab? THAT was never part of the Roncz canard plans.
  2. That depiction of the Roncz canard is actually incorrect. The elevator hinge line is in the wrong place. It also looks like it has a Jimmy Durante schnoz (bump on the nose)….

 

David J. Gall

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of David J. Gall
Sent: Monday, December 16, 2019 3:56 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Bruce's tuft study on sparrow strainers

 

Jay,

 

No, but you’re getting MUCH closer. Think full-span fixed trim tab. Like on the paper airplane you made as a kid: bend the trailing edge up a little bit. The million-dollar answer that makes guys like Roncz famous is to define “how much” to bend it up. So, go back to the Rutan Canard Pusher newsletters where Burt defines the criteria, then go get X-Foil or even Roncz’s own tool (the modified Eppler code) and solve the problem the same way Roncz did. It only took Roncz et. al four canards to get the whole thing right – you should be able to do this lesser task with just one (full-span) elevator, maybe one (full-span) elevator modified (slightly) a couple times to tweak it to perfection….

 

David J. Gall

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Jay Scheevel
Sent: Monday, December 16, 2019 3:46 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Bruce's tuft study on sparrow strainers

 

OK, re-read your note, and now I get it: Use Roncz anti-servo trim tab on the stock LS-1 elevator. Right? 

 

If so, you are saying mount a servo such as shown on the trailing edge below?

 

 

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of David J. Gall
Sent: Monday, December 16, 2019 4:15 PM
To: main@q-list.groups.io
Subject: Re: [Q-List] Bruce's tuft study on sparrow strainers

 

Jay,

 

Nope. That’s not what I said. 

 

Not even close.

 

 

David “Jimmeh” Gall

 

On Dec 16, 2019, at 12:29 PM, Jay Scheevel <jay@...> wrote:



Thanks David,

 

Am aware of the Roncz canard and its implementation on the EZ, but to directly convert the Quickie to that implementation would require re-engineering the elevator actuator. Could do that if starting my canard build over from scratch, but to retrofit on the existing Q2 with the LS-1 already installed would be difficult. The Roncz elevator solution is a sort of a fowler flap and would also require installation of the trailing edge trim. My design is a compromise to be sure, but could be directly retrofit in the existing slot with the same torque tube system as is currently in place and eliminate the sparrow strainer. Don’t know if that will ever happen, but it would be a doable retrofit.

 

Cheers,
Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of David J. Gall
Sent: Monday, December 16, 2019 12:49 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Bruce's tuft study on sparrow strainers

 

Jay,

 

John Roncz came up with the solution to this many years ago. It’s called the “Roncz canard” in the Long-EZ community. It’s an excellent airfoil, but particularly important is what he did to the elevator. The same technique could be used on the LS-1 elevator to mitigate the elevator hinge moment. It can be modeled fairly accurately in X-foil or in Roncz’s modified Eppler airfoil code that he used back then (freely available on the internet). Just gotta tweak it so the elevator floating angle is stable and appropriate for the airplane’s approximate maximum range low cruise airspeed so that if the trim and elevator control systems accidentally disconnect in flight the airplane will be able to continue flight and land using engine power modulation (and reflex if installed) as primary pitch control. Rutan laid out all these requirements in one of the Canard Pusher newsletters in the 1980s.

 

David J. Gall

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Jay Scheevel
Sent: Monday, December 16, 2019 8:10 AM
To: main@Q-List.groups.io
Subject: [Q-List] Bruce's tuft study on sparrow strainers

 

Thanks for the cool tuft study data, Bruce. My nerdiness must be rubbing off on you, or maybe you are just retired and want something time consuming to do.

 

Seriously, That is an interesting observation. Ideally, you would like your “trim” surfaces, such as the sparrow strainer to be well behaved under all flight conditions, but you have demonstrated that this is not the case. The sparrow strainer flies at a high AOA (negative) all the time, so as to apply a large load to the trailing edge of the elevator, push it into an accelerated condition and boom, you get it to stall. The need for them is entirely the because the aft-1/3 of the LS-1 airfoil has a significant camber on the underside. This camber is by design yielding favorable characteristics when incorporated on a non-articulated airfoil, but when you incorporate an articulated trailing edge (elevator), then the asymmetric force becomes torque on the torque tube and stick deflection instead of into a forward pitching component applied to the rigid wing structure. By countering this effect with the sparrow strainer you actually loose some of the positive characteristics of the pitching moment, and you add a lot of drag. If you could manage it as a pilot, and this is not recommended, the LS-1 would fly better and be more efficient if you could hold the elevator neutral with the stick. But this would require always be pulling lots of aft stick-force. The stick force would be very large in full cruise, and you would never find a hands off condition. It gives you an appreciation for the force that the sparrow strainer supports are experiencing constantly in flight, and why one might potentially depart the aircraft….requiring above average flying skills to recover.

 

I have modeled the forces on the LS-1 elevator and have also designed a modified LS-1 airfoil with the rear portion of the camber removed, where the forces on the redesigned elevator are balanced, (so the sparrow strainer would not be required). I have thought that sometime I would like to build a new set of these redesigned elevators and put them on my plane, but I am just getting comfortable flying with the plans design. On the redesigned airfoil, the lift profile and polars are essentially identical to the LS-1, but what is the big unknown is how the redesigned elevator would impact that stall behavior. Small changes at the trailing edge can be quite impactful on stall, and my modeling method cannot model the complexity of airflow at stall.

 

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Bruce Crain
Sent: Sunday, December 15, 2019 9:32 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Yahoo! Groups Shuck Airfoil

 

Hi Jay!

Not sure I really care to know.  Either way I will still be aviating in both and won't put any more sound insulation in either one.  (more weight)

 

On a side note I have been doing some tuft testing which might be more informational.  I have found out that if I pull up the nose and then unload it by pushing forward on the stick my sparrow strainers are stalling on the bottom side.  My TriQ will not recover in most instances until I stall out or slow down the airspeed a bunch so that I can pull the stick enough for the strainers to reattach the air underneath them.  I just received some vortex generators to put on the bottom of the strainers to do more testing and will hopefully have them in place this week to test.

 

I have noticed in the past that when I do an aileron roll this happens.  I have been all though the elevators and ailerons to make sure they were tight and they now are very solid.  So then I thought that maybe the wingtip vortices were coming up from the canard and rolling down on the main wing.  That never really looked like a good theory.  So I installed yarn tufts to see just what was going on.  When I flew it started to dawn on me that the elevator was coming up every time I experienced the phenomenon.  So I had a good idea that something much simpler was happening and it kept pointing to the sparrow strainer.  After talking with Paul Fisher, Jerry Marstall, Sammy Hoskins, and even Scott Swing at Velocity I decided we were looking at a stall.  Sure enough when I went up with the tufts in place on the canard and the top and bottom of the sparrow strainers I thought "what if I just pull up and then push forward on the stick could I replicate the problem".  When I pulled up and then unloaded the canard by pushing over the sparrow strainers held for a bit and then they relaxed to stick forward an inch or so.  I looked out and saw the elevators up about and inch or so and videoed the tufts on the bottom of the strainer disappear and the tufts on the top tufts wrap around the back of the strainer and disappear forward under the strainer!  I spoke with Paul, Jerry and Scott again and Scott was freaked but agreed that was what is happening.

 

Bingo!  Now I have to fix it so that is where the vortex generator come in.  The strainers are a really sensitive trim from dealing with them in the past plus I have them mounted half way outboard on the elevator.  I also have 1.2 degrees incidence up on the canard and .8 degrees up on the main wing so we are talking apples to oranges.

 

Sure I could just fly the Q and not go negative on the elevator enough to stall them but I like to do aileron rolls when I am board. I believe you and I experienced the stall when you were getting time in my Q before your first flight.  So we educate and experiment and come out improving the species. 

---------- Original Message ----------
From: "Jay Scheevel" <jay@...>
To: main@Q-List.groups.io
Subject: Re: [Q-List] Yahoo! Groups Shuck Airfoil
Date: Sun, 15 Dec 2019 19:53:06 -0700

Hi Bruce,

 

If you have an iPhone it has an app available that measures abient noise level. You could give that a try.

 

Cheers,

Jay

 

Sent from my Verizon Wireless 4G LTE DROID



Bruce Crain <jcrain2@...> wrote:

I have not noticed which one is quieter.  Will try to do that in the future.  Trouble is remembering how loud the other plane is between switches.

I will tell Charlie hello for you Dr Mike!

Bruce

---------- Original Message ----------
From: "Mike Shuck via Groups.Io" <mikeshuck2001@...>
To: "main@Q-List.groups.io" <main@Q-List.groups.io>
Subject: Re: [Q-List] Yahoo! Groups Shuck Airfoil
Date: Mon, 16 Dec 2019 01:37:25 +0000 (UTC)

Hi Mike, 

 

My RV6A is noisy. I have a Clark headset modified for active noise reduction but my new Zulu 3 is quieter. I have a Lycoming O-320 E2D 150 with a metal Sensinich prop. I have problem believing a Quickie 200 is quieter.

 

Mike

 

 

On Sun, Dec 15, 2019 at 7:33 PM, Mike Dwyer

<q200pilot@...> wrote:

I flew in a RV4 recently and I think the inside cockpit of the RV is a lot noisier than a Q200.  I'd expect the fiberglass sandwich to dampen some noise.  

Any other opinions?

Fly Safe,

Mike Dwyer

 

YouTube Videos: https://goo.gl/yKEHfK

Q200 Website: http://goo.gl/V8IrJF

 

On Sun, Dec 15, 2019 at 8:14 PM Bruce Crain <jcrain2@...> wrote:

Sweet!  Hope you design a mach .5 airfoil for the Quickie guys  Wouldn't that be sweet!  

I still have my TriQ 200 but I went over to the "Dark Side" when my hanger mate Charlie Calivas sold me his RV 6 for a song and a dance and then proceeded to help me rebuild the engine!  My son Jake calls me "2 planes Crain"!  
Have a Merry Christmas!

Bruce and Honeylamb Crain
---------- Original Message ----------
From: "Mike Shuck via Groups.Io" <mikeshuck2001=yahoo.com@groups.io>
To: "main@Q-List.groups.io" <main@Q-List.groups.io>
Subject: Re: [Q-List] Yahoo! Groups Shuck Airfoil
Date: Sun, 15 Dec 2019 04:06:52 +0000 (UTC)

Bruce!

Good to hear from you as well. Things are great in Wichita. I'm still designing GA airfoils and flying my  RV6A and Cessna 120. I went through Emporia two weeks ago and it reminded me of when you, your son, and I got weathered in coming back from the Quickie fly-in at Ottawa. 

 

Great hearing from you! My thanks to the Q-List group for letting me "announce" our moving Shuck Airfoil from Yahoo! Groups to Groups.io !

 

Best wishes!

Mike Shuck

Wichita, KS

 

 

 

 

On Sat, Dec 14, 2019 at 9:44 PM, Bruce Crain

<jcrain2@...> wrote:

Good to hear from you again Dr Shuck!  How are things in Wichita?

Bruce Crain

---------- Original Message ----------
From: "Mike Shuck via Groups.Io" <mikeshuck2001=yahoo.com@groups.io>
To: "main@Q-List.groups.io" <main@Q-List.groups.io>
Subject: [Q-List] Yahoo! Groups Shuck Airfoil
Date: Sun, 15 Dec 2019 00:24:29 +0000 (UTC)

Just to let you know I am in process of moving the former Yahoo! Groups Shuck Airfoil to:

 

 

I was late getting the mailing list moved over so I would be very thankful if you would post this as many

of the Shuck Airfoil group at Yahoo! Groups also were members of Q-List.

 

Many thanks!

 

Mike Shuck

Moderator of the former Yahoo! Groups Shuck Airfoil

 

 

 

 

 

 

 

 

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