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Re: Wing load testing and max weight
Not to put words in Charlie’s mouth, but I think I heard him say (when he was showing me a structural simulation of the LS1 canard on his computer) that he felt the weak link in the chain was the skin/foam sandwich forward of the tube spar and inboard but not too far from the fuselage. That seems to be the place where the delamination has happened on numerous aircraft, even where the canard did not break.
The official QAC line was that the tubular spar was required because of the thin profile of the LS1 would not allow enough flexural strength if it that shape of airfoil was laid up conventionally. I think a properly engineered I-beam spar (or two) would probably fill the bill, but no one has tested that idea to my knowledge. QAC probably looked a the tube spar as a way of ensuring that customers did not drift towards hand building Q200’s without buying kit components from them. I would not write that motivation off entirely.
So many more options exist now. I think anything requiring an autoclave should be ruled out for the general public, as it is not a tool that is available to most. The best bet would be to find an enthusiastic, enterprising, young graduate student, who is good with composites analysis and solid works, and ask them to do some modeling of proven hand laid up carbon fiber spar configurations subjected to end loading (like the standard Q and Dfly configuration), combined with line loading that would simulate the fuselage shell wall loads. If it was proven by computer modeling, then you would only have to build one canard design for testing to failure.
My 2 cents.
Cheers, Jay
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of smeshno1@...
Sent: Monday, February 15, 2021 12:45 PM To: main@Q-List.groups.io Subject: Re: [Q-List] Wing load testing and max weight
I couldn't recall if it was the Wing or Canard..thank you for the clarification, Jay. Here is what Charlie and I both are concerned about.. the Canard, especially in the MKI config, takes a beating in this design. Neither D-fly or Q2 have had the Canard tested (that we know of) and I cannot be certain of the load limits in my own aircraft.
So the airplane geek I was trained to be finds this situation unacceptable. Too many years in the factories worrying about "what if's!" I am concerned we have had structural fails..thank goodness not to the point of augering in from 10,000 feet. There are indications of upper skin delam from the canard core..and crush of the core leading to compression fails right where we expect these conditions to happen. The bond between the core and upper glass layup degrades over time...so the margin in safety to peak load will be reduced.
So I have the question here.. I can build a fixture that can easily use my 1/2 ton Dodge truck to provide a stabilized test fixture (the data plate on the truck indicates the mass we have to work with, also not a problem having certificated scales weigh the vehicle). How much in todays materials would a canard cost to build? No need to add finishes because these are not going flying..these are going to test to fail (if possible). I prefer testing the Dragonfly Canard for the reasons explained before. The M.E. within wants to test what is more likely of a successful build by the homebuilder in her/his own Shop.
We MIGHT be able to effectively tool for Q2 Spars and test those also. We would need to know the exact ply schedule, finish, and resin used at QAC. What finish dry carbon fiber also. What tapes used? A far superior part would be possible with pre-preg ribbon and the correct mandrel...but then the problem of autoclave and accurate cure arises. It might be possible to correctly pre-preg fab the tapered tube Spars using internal inflated balloon methods and then cure the entire tool with the layup and mandrels in a controlled oven.
Village Idiot Vern
From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Jay Scheevel <jay@...>
I think that Waddelow load tested his LS1 spar-less canard, but I do not know the limits. Maybe Bruce Crain has that information.
The test of the main wing at LVK was in 2008 and tested to a max of +4.4 G’s (2000 lb. of sandbags) with deflection of 10.5 inches on each wingtip, that returned to its original shape.
I agree with what Vern is saying. I only thought I would look up the data so I can correct what I said earlier about 18” of deflection. Was really 10.5”
Cheers, Jay
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of smeshno1@...
The only test was in the news letters. Q Canard was tested in the past with static to 1200 lbs (positive). Sand bags from the local Big Box home improvement center. On release, the tested surface resumed original design config(Q2, MKI Anhedral if my memory is correct)
The point is, from all builders/owners in the newsletters or blogs, of yet no test of either Dragonfly or Rutan Q surfaces (Wing or Canard) have been performed to failure..so there is no definite known max load other than Finite Element work.
Here is one project I had a bit of a hand in
She went 150% in this photo (and did not break). I've flown over the Atlantic in a 787-9 but the wings were not at this point of flex. I am pretty sure if they were my wife would have been a bit more than worried since she was with me on that flight from Stockholm to Ft Lauderdale.
When fail is reached it is upper surface compression, most often beginning at shear surface bondline (contact) from the spar/ribs to IML of the upper surface layup. Failure happens almost instantly but the strain gauges tell the tale afterword.
In our case the question arises of what is the bond of the glass layup to the solid core foam doing? The Dragonfly having a different spar method than the Rutan carbon tube, so that is an important factor also. Delam of the skins from the foam is what we aught be expecting. The flex of the resin/glass compared to the foams involved.
Big question, and now BOTH foam and resin glass are different than in the 80's. I have extra orange Q2 foam to build the test surfaces but then again.. we can't obtain that same material now. The goal is to use what we can get and perhaps "back test" to the older material so the "as built" materials properties are known as well.
One of my "wish list" projects is to get the time and materials together to build a set of test surfaces to go to failure in both positive and negative G. I have not heard of any flutter issues with either structural design. Vne may need be exceeded to discover that (sarcasm on high!)
Vern in frozen Oklahoma (Feb 12)
From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Jay Scheevel <jay@...>
Hi Mike and Ryan,
I plugged 800 pounds GW into the Q200 aerodynamic model that I created several years ago (modeling the plans-built Q200). In this model, I get 67 mph CAS as the Vmin**, in ground effect. When I increase the GW to 1400 pounds, I get a Vmin of 88 mph in ground effect. So that is probably as close an answer as you are going to get to your question about flying at 1400 pounds.
I usually fly between 1000 and 1100 pounds GW. For those weights, the model produces a Vmin of 75 and 78 mph respectively.
I have also built a model that is customized to match my personal aircraft performance (Tri-Q2, with some minor aero mods). I get a Vmin of 70 mph at 1000 GW, and 74 mph at 1100 pounds. This is spot on with what I have measured in flight. At 1400 pounds, my plane would theoretically have a Vmin of 84 mph (I won’t be flight testing this!)
Cheers, Jay
**I say Vmin because with a tandem wing configuration never really stalls, it just reaches a configuration where airspeed cannot get any lower and then the decent rate makes up for any energy deficit required to hold that airspeed…..but that is another story, for another time. From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Mike Dwyer
If the stall speed is 67mph at 800 lbs, what would it be at 1400 lbs?
The tail dragger LS1 canard is sized for the landing impact, not the in flight load.
The factory Q200 had a 1100 lb gross weight limit. Obviously they didn't think 1400 is safe.
Mike Q200 N3QP
On Thu, Feb 11, 2021, 8:00 PM ryan goodman via groups.io <elboy0712=yahoo.com@groups.io> wrote:
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Re: Wing load testing and max weight
I couldn't recall if it was the Wing or Canard..thank you for the clarification, Jay. Here is what Charlie and I both are
concerned about.. the Canard, especially in the MKI config, takes a beating in this design. Neither D-fly or Q2 have
had the Canard tested (that we know of) and I cannot be certain of the load limits in my own aircraft.
So the airplane geek I was trained to be finds this situation unacceptable. Too many years in the factories worrying
about "what if's!" I am concerned we have had structural fails..thank goodness not to the point of
augering in from 10,000 feet. There are indications of upper skin delam from the canard core..and crush of the core
leading to compression fails right where we expect these conditions to happen. The bond between the core and upper
glass layup degrades over time...so the margin in safety to peak
load will be reduced.
So I have the question here.. I can build a fixture that can easily use my 1/2 ton Dodge truck to provide a stabilized test
fixture (the data plate on the truck indicates the mass we have to work with, also not a problem having certificated scales
weigh the vehicle). How much in todays materials would a canard cost to build? No need to add finishes because these
are not going flying..these are going to test to fail (if
possible). I prefer testing the Dragonfly Canard for the reasons
explained before. The M.E. within wants to test what is
more likely of a successful build by the homebuilder in her/his
own Shop.
We MIGHT be able to effectively tool for Q2 Spars and test
those also. We would need to know the exact ply schedule,
finish, and resin used at QAC. What finish dry carbon fiber also. What tapes used? A far superior part would be possible
with pre-preg ribbon and the correct mandrel...but
then the problem of autoclave and accurate cure arises. It might be
possible to correctly pre-preg fab the tapered tube Spars using internal inflated balloon methods and then cure the entire
tool with the layup and mandrels in a
controlled oven.
Village Idiot Vern
From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Jay Scheevel <jay@...>
Sent: Friday, February 12, 2021 3:20 PM To: main@Q-List.groups.io <main@Q-List.groups.io> Subject: Re: [Q-List] Wing load testing and max weight I think that Waddelow load tested his LS1 spar-less canard, but I do not know the limits. Maybe Bruce Crain has that information.
The test of the main wing at LVK was in 2008 and tested to a max of +4.4 G’s (2000 lb. of sandbags) with deflection of 10.5 inches on each wingtip, that returned to its original shape.
I agree with what Vern is saying. I only thought I would look up the data so I can correct what I said earlier about 18” of deflection. Was really 10.5”
Cheers, Jay
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of smeshno1@...
The only test was in the news letters. Q Canard was tested in the past with static to 1200 lbs (positive). Sand bags from the local Big Box home improvement center. On release, the tested surface resumed original design config(Q2, MKI Anhedral if my memory is correct)
The point is, from all builders/owners in the newsletters or blogs, of yet no test of either Dragonfly or Rutan Q surfaces (Wing or Canard) have been performed to failure..so there is no definite known max load other than Finite Element work.
Here is one project I had a bit of a hand in
She went 150% in this photo (and did not break). I've flown over the Atlantic in a 787-9 but the wings were not at this point of flex. I am pretty sure if they were my wife would have been a bit more than worried since she was with me on that flight from Stockholm to Ft Lauderdale.
When fail is reached it is upper surface compression, most often beginning at shear surface bondline (contact) from the spar/ribs to IML of the upper surface layup. Failure happens almost instantly but the strain gauges tell the tale afterword.
In our case the question arises of what is the bond of the glass layup to the solid core foam doing? The Dragonfly having a different spar method than the Rutan carbon tube, so that is an important factor also. Delam of the skins from the foam is what we aught be expecting. The flex of the resin/glass compared to the foams involved.
Big question, and now BOTH foam and resin glass are different than in the 80's. I have extra orange Q2 foam to build the test surfaces but then again.. we can't obtain that same material now. The goal is to use what we can get and perhaps "back test" to the older material so the "as built" materials properties are known as well.
One of my "wish list" projects is to get the time and materials together to build a set of test surfaces to go to failure in both positive and negative G. I have not heard of any flutter issues with either structural design. Vne may need be exceeded to discover that (sarcasm on high!)
Vern in frozen Oklahoma (Feb 12)
From:
main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Jay Scheevel <jay@...>
Hi Mike and Ryan,
I plugged 800 pounds GW into the Q200 aerodynamic model that I created several years ago (modeling the plans-built Q200). In this model, I get 67 mph CAS as the Vmin**, in ground effect. When I increase the GW to 1400 pounds, I get a Vmin of 88 mph in ground effect. So that is probably as close an answer as you are going to get to your question about flying at 1400 pounds.
I usually fly between 1000 and 1100 pounds GW. For those weights, the model produces a Vmin of 75 and 78 mph respectively.
I have also built a model that is customized to match my personal aircraft performance (Tri-Q2, with some minor aero mods). I get a Vmin of 70 mph at 1000 GW, and 74 mph at 1100 pounds. This is spot on with what I have measured in flight. At 1400 pounds, my plane would theoretically have a Vmin of 84 mph (I won’t be flight testing this!)
Cheers, Jay
**I say Vmin because with a tandem wing configuration never really stalls, it just reaches a configuration where airspeed cannot get any lower and then the decent rate makes up for any energy deficit required to hold that airspeed…..but that is another story, for another time.
From: main@Q-List.groups.io <main@Q-List.groups.io>
On Behalf Of Mike Dwyer
If the stall speed is 67mph at 800 lbs, what would it be at 1400 lbs?
The tail dragger LS1 canard is sized for the landing impact, not the in flight load.
The factory Q200 had a 1100 lb gross weight limit. Obviously they didn't think 1400 is safe.
Mike Q200 N3QP
On Thu, Feb 11, 2021, 8:00 PM ryan goodman via groups.io <elboy0712=yahoo.com@groups.io> wrote:
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Re: Nose Gear for Tri-Qs
Brad Lewis
What's the nose wheel size?
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Re: Dave Smith's Q-Tour is uploaded to YouTube
Rick Hole
Thanks Dave. I enjoyed your presentation Rick Hole
On Mon, Feb 15, 2021 at 12:02 PM Sam Hoskins <sam.hoskins@...> wrote: Here is Dave's tour of his very plans built Revmaster powered Q-2. First flight was in 1984.
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Re: Dave Smith's Q-Tour is uploaded to YouTube
Anthony P
Very informative and fun presentation. (as they all are)
Thanks to all who made this happen.
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Dave Smith's Q-Tour is uploaded to YouTube
Here is Dave's tour of his very plans built Revmaster powered Q-2. First flight was in 1984.
Dave, thanks for sharing with us. https://youtu.be/MHrDOafL2j0 Sam
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Re: Inactive Q projects
Pete Stein
Hello One Sky Dog, I just spoke to my EAA group and they're interested in these aircraft to be donated to the local high school for assembly. How can I get in touch with them? Thanks Pete
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Re: Wing load testing and max weight
Howdy Jim.
You are correct QAC provided my kit to the original Nevada buyer; and I agree with staying to the published
MTOW limits..for sure until
actual finished surfaces are tested. My "parts pile" was missing the tube spars..in
fact.. about half of
the kit was missing. RAF was a plans supplier. A wise move on Burt's part.
Scott performing just the Spar test is understood (would be the minimum)...in todays materials and methods
we will have gained in margins
to failure. Especially with ribbon/mandrel methods and the superior
autoclave controls now..the
prepregs today also far superior than even 10 years ago.
Maybe Gulfstream will sell out the Nordam NTR equipment in Owasso Oklahoma and I'd have the cash to
buy it all for the weight in scrap prices!!?? I'd be tickled
pink to be a parts provider to the experimental world.
I was at Nordam on the G600 Nacelle/Cowling for Pratt and
Whitney engines back in 2017/2018 during First Article.
The nice thing about Contract Engineering is we get to
see all kinds of innovative methods and equipment.
Meredith poured in over $200 million and then had to toss in the towel due mostly to P&W problems with the
geared fan concept. Same problems with the A320 Neo engines. I'd estimate that Nordam spent around $60 million
in composite manufacturing equipment. Gulfstream bought the loan out of bankruptcy and took the facility.
Some factors changed are also the surface finish of the glass used. Many changes in fiber blends since
the 80's and the current finishes offer much better bond in the resin than in the past. That is why I am
encouraged todays build materials and results would be better.
I am itching to test the Dragonfly surfaces as I am prejudiced due to my own project. D-fly "design" are
also possible to build 100% from the home shop environment.. the tooling to set up for Q200 tube spars
being a big hurdle for new builders. Not such a simple task for long time plastic airplane folks with limited
budgets either. Hard to justify tooling up for a one time build.
Vern
(Next Contract might be on VC-25 ...again)
From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Jim Patillo <Logistics_engineering@...>
Sent: Friday, February 12, 2021 3:00 PM To: main@Q-List.groups.io <main@Q-List.groups.io> Subject: Re: [Q-List] Wing load testing and max weight
Hi Vern,
The carbon spar Q200 was introduced by QAC and not Bert Rutan. Scott Swing load tested the spars to failure using a simple method of putting the spar in an elevated aluminum device with loading at the tip until failure. If the spar didn't sag to a defined height
after a certain load and time, it passed and was shipped. Several didn't meet spec and I believe Scott even used one in his Q after repair.
I know a little bit about this as my right spar failed at 200 hours under where passenger legs go, due to a stress riser from the aluminum fixture. I repaired mine back then and the plane now has hundreds of hours on it after failure. People should be very
careful at gross weights over 1,300 lbs. Just my opinion.
Regards,
Jim
N46JP Q200
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Re: Wing load testing and max weight
I think that Waddelow load tested his LS1 spar-less canard, but I do not know the limits. Maybe Bruce Crain has that information.
The test of the main wing at LVK was in 2008 and tested to a max of +4.4 G’s (2000 lb. of sandbags) with deflection of 10.5 inches on each wingtip, that returned to its original shape.
I agree with what Vern is saying. I only thought I would look up the data so I can correct what I said earlier about 18” of deflection. Was really 10.5”
Cheers, Jay
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of smeshno1@...
Sent: Friday, February 12, 2021 1:36 PM To: main@Q-List.groups.io Subject: Re: [Q-List] Wing load testing and max weight
The only test was in the news letters. Q Canard was tested in the past with static to 1200 lbs (positive). Sand bags from the local Big Box home improvement center. On release, the tested surface resumed original design config(Q2, MKI Anhedral if my memory is correct)
The point is, from all builders/owners in the newsletters or blogs, of yet no test of either Dragonfly or Rutan Q surfaces (Wing or Canard) have been performed to failure..so there is no definite known max load other than Finite Element work.
Here is one project I had a bit of a hand in
She went 150% in this photo (and did not break). I've flown over the Atlantic in a 787-9 but the wings were not at this point of flex. I am pretty sure if they were my wife would have been a bit more than worried since she was with me on that flight from Stockholm to Ft Lauderdale.
When fail is reached it is upper surface compression, most often beginning at shear surface bondline (contact) from the spar/ribs to IML of the upper surface layup. Failure happens almost instantly but the strain gauges tell the tale afterword.
In our case the question arises of what is the bond of the glass layup to the solid core foam doing? The Dragonfly having a different spar method than the Rutan carbon tube, so that is an important factor also. Delam of the skins from the foam is what we aught be expecting. The flex of the resin/glass compared to the foams involved.
Big question, and now BOTH foam and resin glass are different than in the 80's. I have extra orange Q2 foam to build the test surfaces but then again.. we can't obtain that same material now. The goal is to use what we can get and perhaps "back test" to the older material so the "as built" materials properties are known as well.
One of my "wish list" projects is to get the time and materials together to build a set of test surfaces to go to failure in both positive and negative G. I have not heard of any flutter issues with either structural design. Vne may need be exceeded to discover that (sarcasm on high!)
Vern in frozen Oklahoma (Feb 12)
From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Jay Scheevel <jay@...>
Hi Mike and Ryan,
I plugged 800 pounds GW into the Q200 aerodynamic model that I created several years ago (modeling the plans-built Q200). In this model, I get 67 mph CAS as the Vmin**, in ground effect. When I increase the GW to 1400 pounds, I get a Vmin of 88 mph in ground effect. So that is probably as close an answer as you are going to get to your question about flying at 1400 pounds.
I usually fly between 1000 and 1100 pounds GW. For those weights, the model produces a Vmin of 75 and 78 mph respectively.
I have also built a model that is customized to match my personal aircraft performance (Tri-Q2, with some minor aero mods). I get a Vmin of 70 mph at 1000 GW, and 74 mph at 1100 pounds. This is spot on with what I have measured in flight. At 1400 pounds, my plane would theoretically have a Vmin of 84 mph (I won’t be flight testing this!)
Cheers, Jay
**I say Vmin because with a tandem wing configuration never really stalls, it just reaches a configuration where airspeed cannot get any lower and then the decent rate makes up for any energy deficit required to hold that airspeed…..but that is another story, for another time. From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Mike Dwyer
If the stall speed is 67mph at 800 lbs, what would it be at 1400 lbs?
The tail dragger LS1 canard is sized for the landing impact, not the in flight load.
The factory Q200 had a 1100 lb gross weight limit. Obviously they didn't think 1400 is safe.
Mike Q200 N3QP
On Thu, Feb 11, 2021, 8:00 PM ryan goodman via groups.io <elboy0712=yahoo.com@groups.io> wrote:
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Re: Wing load testing and max weight
Hi Vern,
The carbon spar Q200 was introduced by QAC and not Bert Rutan. Scott Swing load tested the spars to failure using a simple method of putting the spar in an elevated aluminum device with loading at the tip until failure. If the spar didn't sag to a defined height
after a certain load and time, it passed and was shipped. Several didn't meet spec and I believe Scott even used one in his Q after repair.
I know a little bit about this as my right spar failed at 200 hours under where passenger legs go, due to a stress riser from the aluminum fixture. I repaired mine back then and the plane now has hundreds of hours on it after failure. People should be very
careful at gross weights over 1,300 lbs. Just my opinion.
Regards,
Jim
N46JP Q200
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Re: Wing load testing and max weight
So 84 mph CAS is the number that I compute for level flight in ground effect at 1296 pound GW. I don’t think it should feel mushy, since you will not leave the runway until it is ready to fly. I think I computed your ground angle of attack at around 7 degrees once upon a time, so once you reach the magic speed, you are airborne at that angle and that is well below the critical stall angle of the canard.
You should have fun in Corbin’s plane. It seems like it is a rocket!
Cheers, Jay
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Jim Patillo
Sent: Friday, February 12, 2021 1:13 PM To: main@Q-List.groups.io Subject: Re: [Q-List] Wing load testing and max weight
No reflexor at 1296 lbs. at takeoff. I only use reflexor after landing and at gross in flight cruise to shift cg forward. Jim N46JP Q200
Sent from Outer Space From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Jay Scheevel <jay@...>
Hi Jim,
Do you use reflexor when you are flying at 1296. It will make a difference in the calculation. Let me know and I will do the calculation with reflexor. With no reflexor I get 84 mph indicated at that weight for the stock Q200.
Cheers, Jay
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Jim Patillo
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Re: Wing load testing and max weight
The only test was in the news letters. Q Canard was tested in the past with static to 1200 lbs (positive).
Sand bags from the local Big Box home improvement center. On release, the tested surface resumed
original design config(Q2, MKI Anhedral if my memory is correct)
The point is, from all builders/owners in the newsletters or blogs, of yet no test of either Dragonfly or Rutan Q surfaces
(Wing or Canard) have been performed to failure..so there is no definite known max load other than Finite Element work.
Here is one project I had a bit of a hand in
She went 150% in this photo (and did not break). I've flown over the Atlantic in a 787-9 but the wings were
not at this point of flex. I am pretty sure if they were my wife would have been a bit more than worried since
she was with me on that flight from Stockholm to Ft Lauderdale.
When fail is reached it is upper surface compression, most often beginning at shear surface bondline (contact) from
the spar/ribs to IML of the upper surface layup. Failure happens almost instantly but the strain gauges tell the tale
afterword.
In our case the question arises of what is the bond of the glass layup to the solid core foam doing? The Dragonfly
having a different spar method than the Rutan carbon tube, so that is an important factor also. Delam of the skins
from the foam is what we aught be expecting. The flex of
the resin/glass compared to the foams involved.
Big question, and now BOTH foam and resin glass are different
than in the 80's. I have extra orange Q2 foam to
build the test surfaces but then again.. we can't obtain
that same material now. The goal is to use what we can get
and perhaps "back test" to the older material so the "as
built" materials properties are known as well.
One of my "wish list" projects is to get the time and materials together to build a set of test surfaces to go to failure
in both positive and negative G. I have not heard of any
flutter issues with either structural design.
Vne may need be exceeded to discover that (sarcasm
on high!)
Vern in frozen Oklahoma (Feb 12)
From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Jay Scheevel <jay@...>
Sent: Friday, February 12, 2021 10:22 AM To: main@Q-List.groups.io <main@Q-List.groups.io> Subject: Re: [Q-List] Wing load testing and max weight Hi Mike and Ryan,
I plugged 800 pounds GW into the Q200 aerodynamic model that I created several years ago (modeling the plans-built Q200). In this model, I get 67 mph CAS as the Vmin**, in ground effect. When I increase the GW to 1400 pounds, I get a Vmin of 88 mph in ground effect. So that is probably as close an answer as you are going to get to your question about flying at 1400 pounds.
I usually fly between 1000 and 1100 pounds GW. For those weights, the model produces a Vmin of 75 and 78 mph respectively.
I have also built a model that is customized to match my personal aircraft performance (Tri-Q2, with some minor aero mods). I get a Vmin of 70 mph at 1000 GW, and 74 mph at 1100 pounds. This is spot on with what I have measured in flight. At 1400 pounds, my plane would theoretically have a Vmin of 84 mph (I won’t be flight testing this!)
Cheers, Jay
**I say Vmin because with a tandem wing configuration never really stalls, it just reaches a configuration where airspeed cannot get any lower and then the decent rate makes up for any energy deficit required to hold that airspeed…..but that is another story, for another time.
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Mike Dwyer
If the stall speed is 67mph at 800 lbs, what would it be at 1400 lbs?
The tail dragger LS1 canard is sized for the landing impact, not the in flight load.
The factory Q200 had a 1100 lb gross weight limit. Obviously they didn't think 1400 is safe.
Mike Q200 N3QP
On Thu, Feb 11, 2021, 8:00 PM ryan goodman via groups.io <elboy0712=yahoo.com@groups.io> wrote:
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Re: Wing load testing and max weight
No reflexor at 1296 lbs. at takeoff. I only use reflexor after landing and at gross in flight cruise to shift cg forward.
Jim
N46JP Q200
Sent from Outer Space
From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Jay Scheevel <jay@...>
Sent: Friday, February 12, 2021 11:12:25 AM To: main@Q-List.groups.io <main@Q-List.groups.io> Subject: Re: [Q-List] Wing load testing and max weight Hi Jim,
Do you use reflexor when you are flying at 1296. It will make a difference in the calculation. Let me know and I will do the calculation with reflexor. With no reflexor I get 84 mph indicated at that weight for the stock Q200.
Cheers, Jay
From: main@Q-List.groups.io <main@Q-List.groups.io>
On Behalf Of Jim Patillo
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Re: Wing load testing and max weight
Hi Jim,
Do you use reflexor when you are flying at 1296. It will make a difference in the calculation. Let me know and I will do the calculation with reflexor. With no reflexor I get 84 mph indicated at that weight for the stock Q200.
Cheers, Jay
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Jim Patillo
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Re: Wing load testing and max weight
ryan goodman
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Re: Wing load testing and max weight
Brian Larick
Martin you referenced “new layup schedule for the main wing...is that in the newsletters or somewhere else?
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Brian
On Feb 12, 2021, at 11:29, Jim Patillo <Logistics_engineering@...> wrote:
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Re: Wing load testing and max weight
John Lewis
Greetings Group: In response to the talk about exceeding the design gross weight of a Q200 from a mechanical engineer with lots of dreams and no flying project, this is my two cent's worth. The wings on an airplane, especially a composite like the Q2, are not designed to be strong enough to not break off. They are designed to be STIFF enough not to flex too much, bounce wrong, or flutter. Once they are stiff enough, they are usually vastly over-strong. Testing for breaking alone does not assure they will be airworthy. Please be careful and make sure to test for the right properties when pushing out the boundaries of a design. A load test is a good start, but don't skip taxi and flight testing as well. John Lewis
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Re: Wing load testing and max weight
Ryan, I did not say that! Reread what I said.
Jim
Sent from Outer Space
From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of ryan goodman via groups.io <elboy0712@...>
Sent: Friday, February 12, 2021 9:29:35 AM To: main@Q-List.groups.io <main@Q-List.groups.io> Subject: Re: [Q-List] Wing load testing and max weight
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Re: Wing load testing and max weight
ryan goodman
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Re: Wing load testing and max weight
My analysis does not include the power requirement for climb, since the Vmin numbers I quoted were for maintaining level flight.
The calculation for power required to climb are something like this: 31 horsepower is required for 1000 fpm climb rate for 1000 lb/GW. So, if you are seeing 300 fpm max climb rate at 1000 lb. (at high density altitude), then you only have about 10 excess horsepower at that altitude that you are devoting to climb. The rest of your power is just maintaining level flight airspeed. If you load to 1300 pounds under these same conditions, you will not climb at all.
At my typical density altitude of 6000’, and my normal weight of 1000-1100 pounds, I see around 600 fpm max climb, meaning I have about 20 hp I devote to climbing. If I were to load to 1300 pounds, I would feel the same pucker factor that Jim had at ABQ.
Cheers, Jay
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Jim Patillo
Sent: Friday, February 12, 2021 9:29 AM To: main@Q-List.groups.io Subject: Re: [Q-List] Wing load testing and max weight
I believe the Q2 had a gross weight of 1100 lbs. It was never determined from QAC what the Q200 gross was. I made my 1,325 lbs. after flight testing it to that load and have flown it at that weight a few times. I took off from Albuquerque heading east once in the summer fully loaded, It wasn’t fun. The Sandia Mountain range took a while to get over.
I gave flight training last week to Captain Mike Neidenthal. He’s getting ready for his first solo in the Q200. Our weight was 1296 lbs. The plane flew fine. It just took about 20% more runway to get off. Elevation is 497’ at Livermore. We still had a decent climb at rare 8-900’ fpm.
Jim N46JP - Q200
Sent from Outer Space From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Mike Dwyer <q200pilot@...>
If the stall speed is 67mph at 800 lbs, what would it be at 1400 lbs?
The tail dragger LS1 canard is sized for the landing impact, not the in flight load.
The factory Q200 had a 1100 lb gross weight limit. Obviously they didn't think 1400 is safe.
Mike Q200 N3QP
On Thu, Feb 11, 2021, 8:00 PM ryan goodman via groups.io <elboy0712=yahoo.com@groups.io> wrote:
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