Date   

Re: Quickie insurance

Frankenbird Vern
 

Ya.. I know..we have a similar deal here in Oklahoma at the Municipals. A bit like "buying" a property in the State of Hawaii. 99 year lease for the dirt under and the hangar is added on by your own dollar. Ok..it is just the way it works; unless the coin in the bank account is large enough to buy the acres for a Private field out in the sticks.  I live out in the Sticks of Oklahoma, and it was not because I was forced to.. 
  
 BTW.. I am soon on another gig at the Lazy B.  This time I'm assigned into the black hole stuff. Tinker AFB.  :-/   They are saying at least a 2 year Contract, and expect 3. I sure hate those briefings but I'm terminally greedy. 

 The premium on an Experimental is obscene. Not like a Certificated is any safer.. as we all know any of these machines will kill you given the chance.   
  




Vern,

I did not buy the airport! It is a municipal airport. I did buy into a hangar group.

The only insurance co that would insure my Dragonfly is Avemco even with 500 hrs in type. Liability is as much as liability and hull combined on the Tri-Pacer.

On Friday, March 11, 2022, 2:55 PM, Frankenbird Vern <smeshno1@...> wrote:

Easy solution.. do as Charlie Johnson did for his Dragonfly and BUY the airport.. or a piece of it.  Then tell the municipals to jump off a cliff!

From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Troy Zawlacki <troyzc3@...>
Sent: Friday, March 11, 2022 3:12 AM
To: main@q-list.groups.io <main@Q-List.groups.io>
Subject: Re: [Q-List] Quickie insurance
 
This is good to know and it seems like im getting consistent info from the insurance agent at least. 

I’m getting into exactly the catch 22 I predicted. I’m trying to figure out a place to put the plane for final inspection and phase 1 fly off, and the airports require liability insurance for a tie down or hangar. Then the insurance won’t insure me until after xx amount of hours in the plane… Exactly the conundrum I expected after researching the topic. Something doesn’t add up here.

Taz

On Mar 11, 2022, at 12:15 AM, Corbin via groups.io <c_geiser@...> wrote:

Haha…every once in a while we do joke a little about his special they are.  
--

Corbin 
N121CG


Re: Quickie insurance

One Sky Dog
 

Vern,

I did not buy the airport! It is a municipal airport. I did buy into a hangar group.

The only insurance co that would insure my Dragonfly is Avemco even with 500 hrs in type. Liability is as much as liability and hull combined on the Tri-Pacer.

On Friday, March 11, 2022, 2:55 PM, Frankenbird Vern <smeshno1@...> wrote:

Easy solution.. do as Charlie Johnson did for his Dragonfly and BUY the airport.. or a piece of it.  Then tell the municipals to jump off a cliff!

From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Troy Zawlacki <troyzc3@...>
Sent: Friday, March 11, 2022 3:12 AM
To: main@q-list.groups.io <main@Q-List.groups.io>
Subject: Re: [Q-List] Quickie insurance
 
This is good to know and it seems like im getting consistent info from the insurance agent at least. 

I’m getting into exactly the catch 22 I predicted. I’m trying to figure out a place to put the plane for final inspection and phase 1 fly off, and the airports require liability insurance for a tie down or hangar. Then the insurance won’t insure me until after xx amount of hours in the plane… Exactly the conundrum I expected after researching the topic. Something doesn’t add up here.

Taz

On Mar 11, 2022, at 12:15 AM, Corbin via groups.io <c_geiser@...> wrote:

Haha…every once in a while we do joke a little about his special they are.  
--

Corbin 
N121CG


Re: Quickie insurance

Mike Dwyer
 

Best not to tell the airport manager that your test flying.  I was near finishing my 40 hours when another experimental crashed.  I was asked to leave.  I just let the hour meter run to 40 hours "taxiing around" and got my faa signoff.  Problem solved.
Mike Dwyer Q200

On Fri, Mar 11, 2022, 4:55 PM Frankenbird Vern <smeshno1@...> wrote:
Easy solution.. do as Charlie Johnson did for his Dragonfly and BUY the airport.. or a piece of it.  Then tell the municipals to jump off a cliff!

From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Troy Zawlacki <troyzc3@...>
Sent: Friday, March 11, 2022 3:12 AM
To: main@q-list.groups.io <main@Q-List.groups.io>
Subject: Re: [Q-List] Quickie insurance
 
This is good to know and it seems like im getting consistent info from the insurance agent at least. 

I’m getting into exactly the catch 22 I predicted. I’m trying to figure out a place to put the plane for final inspection and phase 1 fly off, and the airports require liability insurance for a tie down or hangar. Then the insurance won’t insure me until after xx amount of hours in the plane… Exactly the conundrum I expected after researching the topic. Something doesn’t add up here.

Taz

On Mar 11, 2022, at 12:15 AM, Corbin via groups.io <c_geiser@...> wrote:

Haha…every once in a while we do joke a little about his special they are.  
--

Corbin 
N121CG


Re: Quickie insurance

Robert Cringely
 

There are no easy solutions, but there are solutions. Mine isn't easy but it works, sorta.

I run a little startup company that owns several difficult-to-insure aircraft, none of which I am yet qualified to fly, by the way. The two 1980s Falcon 10s aren't difficult to insure (yet -- they are about to be recertified as Experimental R&D, which I am sure will bring new insurance headaches) but the five Lockheed F-104s are another matter altogether. 

The only way to insure the Starfighters is by reinsuring them, much as many companies do with their health insurance.  The planes are "insured" by AVEMCO, but they are actually insured by our company (self-insured) backed-up by a reinsurance policy from Lloyds of London. Reinsurance is insurance for insurance companies. So AVEMCO administers the coverage for a fee but pays no claims, just passing them through to us. If there are any claims (none so far) our little startup pays for the first $1 million, then Lloyds picks-up anything above that amount. We have a separate corporate liability policy that covers the liability portion of all claims with a $100,000 deductible. So to be perfectly accurate we are on the hook for about $600K per airplane taking into account hull value, all for under $100K total per year.

What does that have to do with little experimentals? I use my Thorp T-18 for work so my employment contract includes as a fringe benefit covering my airplane  insurance, which so far has been free for the company. Just to be completely transparent, the insurance is bundled into my hangar benefit (we already had a couple hangars full of jets, remember). Doing it that way allows me to get reimbursed for standard IRS car mileage for my business use of the plane, which I guess in this instance is considered a flying car? I actually make a small profit on the mileage. When I get my turbo-diesel Q1 in the air I'll make an even bigger profit.

Bob



On Fri, Mar 11, 2022 at 1:55 PM Frankenbird Vern <smeshno1@...> wrote:
Easy solution.. do as Charlie Johnson did for his Dragonfly and BUY the airport.. or a piece of it.  Then tell the municipals to jump off a cliff!

From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Troy Zawlacki <troyzc3@...>
Sent: Friday, March 11, 2022 3:12 AM
To: main@q-list.groups.io <main@Q-List.groups.io>
Subject: Re: [Q-List] Quickie insurance
 
This is good to know and it seems like im getting consistent info from the insurance agent at least. 

I’m getting into exactly the catch 22 I predicted. I’m trying to figure out a place to put the plane for final inspection and phase 1 fly off, and the airports require liability insurance for a tie down or hangar. Then the insurance won’t insure me until after xx amount of hours in the plane… Exactly the conundrum I expected after researching the topic. Something doesn’t add up here.

Taz

On Mar 11, 2022, at 12:15 AM, Corbin via groups.io <c_geiser@...> wrote:

Haha…every once in a while we do joke a little about his special they are.  
--

Corbin 
N121CG


Re: Quickie insurance

Frankenbird Vern
 

Easy solution.. do as Charlie Johnson did for his Dragonfly and BUY the airport.. or a piece of it.  Then tell the municipals to jump off a cliff!


From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Troy Zawlacki <troyzc3@...>
Sent: Friday, March 11, 2022 3:12 AM
To: main@q-list.groups.io <main@Q-List.groups.io>
Subject: Re: [Q-List] Quickie insurance
 
This is good to know and it seems like im getting consistent info from the insurance agent at least. 

I’m getting into exactly the catch 22 I predicted. I’m trying to figure out a place to put the plane for final inspection and phase 1 fly off, and the airports require liability insurance for a tie down or hangar. Then the insurance won’t insure me until after xx amount of hours in the plane… Exactly the conundrum I expected after researching the topic. Something doesn’t add up here.

Taz

On Mar 11, 2022, at 12:15 AM, Corbin via groups.io <c_geiser@...> wrote:

Haha…every once in a while we do joke a little about his special they are.  
--

Corbin 
N121CG


Re: Quickie insurance

Sam Hoskins
 

No hull here, either.  When I first looked into it, the insurance company wanted 10% of the aircrafts value, whatever I declared that to be.

So, I just fix it myself, and fix it, and fix it, and fix it.

Sam

On Fri, Mar 11, 2022 at 6:37 AM Jerry Marstall <jerrylm1986@...> wrote:
Never carried Hull insurance. Essentially, if you break, you fix it.  Who else knows how to fix a Q except a Q builder?
Jerry M

On Thu, Mar 10, 2022, 8:30 PM Troy Zawlacki <troyzc3@...> wrote:
Does anyone have recommendations on insurance options for the Q aircraft? The responses I am getting dont look promising and require things like 20 hrs of dual from a CFI who has 10 hrs in a Q (basically impossible). Is everyone just flying without hull insurance for the first 100 hrs? Or do we just realize that hull insurance isn’t worth it for a plane with an upper end value of 30k? Ive never owned before so this is all new to me.

Taz





Re: Quickie insurance

Kevin Boddicker
 

I was covered by Falcon from first flight (3/10/06) with hull ins. at $20,000. NOT IN MOTION. No coverage if the engine was running.
Only stuff like fire, wind, building failure were covered… Did drop hull coverage last year. Seemed like a waste as Mike said in his note. Just got the renewal policy yesterday. My agent is Kris Abernathy. Great guy to work with. 
I had 5 hours in type, logged. At first flight.
It is a Tri Q however. That probably presents less risk in the ins. companies eyes…???


Kevin Boddicker
TriQ 200 N7868B   571 hrs
Luana, IA.



On Mar 11, 2022, at 6:49 AM, Mike Dwyer <q200pilot@...> wrote:

Never had hull insurance.  I built it and figure that I could fix it myself.  36 years of flight so have saved $72,000 so far.
Mike Dwyer Q200

On Thu, Mar 10, 2022, 8:30 PM Troy Zawlacki <troyzc3@...> wrote:
Does anyone have recommendations on insurance options for the Q aircraft? The responses I am getting dont look promising and require things like 20 hrs of dual from a CFI who has 10 hrs in a Q (basically impossible). Is everyone just flying without hull insurance for the first 100 hrs? Or do we just realize that hull insurance isn’t worth it for a plane with an upper end value of 30k? Ive never owned before so this is all new to me.

Taz






Re: Quickie insurance

Mike Dwyer
 

Never had hull insurance.  I built it and figure that I could fix it myself.  36 years of flight so have saved $72,000 so far.
Mike Dwyer Q200

On Thu, Mar 10, 2022, 8:30 PM Troy Zawlacki <troyzc3@...> wrote:
Does anyone have recommendations on insurance options for the Q aircraft? The responses I am getting dont look promising and require things like 20 hrs of dual from a CFI who has 10 hrs in a Q (basically impossible). Is everyone just flying without hull insurance for the first 100 hrs? Or do we just realize that hull insurance isn’t worth it for a plane with an upper end value of 30k? Ive never owned before so this is all new to me.

Taz





Re: Quickie insurance

Jerry Marstall
 

Never carried Hull insurance. Essentially, if you break, you fix it.  Who else knows how to fix a Q except a Q builder?
Jerry M

On Thu, Mar 10, 2022, 8:30 PM Troy Zawlacki <troyzc3@...> wrote:
Does anyone have recommendations on insurance options for the Q aircraft? The responses I am getting dont look promising and require things like 20 hrs of dual from a CFI who has 10 hrs in a Q (basically impossible). Is everyone just flying without hull insurance for the first 100 hrs? Or do we just realize that hull insurance isn’t worth it for a plane with an upper end value of 30k? Ive never owned before so this is all new to me.

Taz





Re: Quickie insurance

Troy Zawlacki
 

This is good to know and it seems like im getting consistent info from the insurance agent at least. 

I’m getting into exactly the catch 22 I predicted. I’m trying to figure out a place to put the plane for final inspection and phase 1 fly off, and the airports require liability insurance for a tie down or hangar. Then the insurance won’t insure me until after xx amount of hours in the plane… Exactly the conundrum I expected after researching the topic. Something doesn’t add up here.

Taz

On Mar 11, 2022, at 12:15 AM, Corbin via groups.io <c_geiser@...> wrote:

Haha…every once in a while we do joke a little about his special they are.  
--

Corbin 
N121CG


Re: Quickie insurance

Corbin <c_geiser@...>
 

Haha…every once in a while we do joke a little about his special they are.  
--

Corbin 
N121CG


Re: Quickie insurance

Michael Dunning
 

Corbin,

You might want to let those two know that they are now walking National Treasures 😉
--
-MD
#2827 (still thinking about planning on visualizing how to finish building)


Re: Quickie insurance

Martin Skiby
 

Call Falcon Insurance. They insured both our TriQ and the Q200

Martin

On Mar 10, 2022, at 7:29 PM, britmcman99 via groups.io <britmcman@...> wrote:

Falcon covered me only after 30 hours with instructor. However, they accepted the builder Bob Malechek to fly those hours off with me. I didn’t opt for hull insurance, only liability. You break it, nobody else is going to be able to fix it. It’s a builder’s airplane, after all. So maybe you might hope for a total write off? This was back in 2004. I got more insurance with Falcon (Global) a few years back and it wasn’t too bad, but again just liability.
Philip Lankford
On Mar 10, 2022, at 5:30 PM, Troy Zawlacki <troyzc3@...> wrote:

Does anyone have recommendations on insurance options for the Q aircraft? The responses I am getting dont look promising and require things like 20 hrs of dual from a CFI who has 10 hrs in a Q (basically impossible). Is everyone just flying without hull insurance for the first 100 hrs? Or do we just realize that hull insurance isn’t worth it for a plane with an upper end value of 30k? Ive never owned before so this is all new to me.

Taz








Re: Quickie insurance

britmcman99
 

Falcon covered me only after 30 hours with instructor. However, they accepted the builder Bob Malechek to fly those hours off with me. I didn’t opt for hull insurance, only liability. You break it, nobody else is going to be able to fix it. It’s a builder’s airplane, after all. So maybe you might hope for a total write off? This was back in 2004. I got more insurance with Falcon (Global) a few years back and it wasn’t too bad, but again just liability.
Philip Lankford

On Mar 10, 2022, at 5:30 PM, Troy Zawlacki <troyzc3@...> wrote:

Does anyone have recommendations on insurance options for the Q aircraft? The responses I am getting dont look promising and require things like 20 hrs of dual from a CFI who has 10 hrs in a Q (basically impossible). Is everyone just flying without hull insurance for the first 100 hrs? Or do we just realize that hull insurance isn’t worth it for a plane with an upper end value of 30k? Ive never owned before so this is all new to me.

Taz




Re: Preliminary analysis of aerodynamics of sparrow strainers (or not)

Jay Scheevel
 

Hi Micheal,

 

Not back yet, but I will give a short response to clarify.. Corrections for the differences in chord were made external to Javafoil. I explain my procedures in the first of the documents that I linked to. I realized that Reynolds number is scale dependent (that is kind of the point, isn’t it?), so I have had to use a Reynolds number in Javafoil, that allows me to reach approximately 1 million effective Reynolds number for the Q2 configuration multifoil. To do this the cord is not unit for either airfoil of the multifoil pairs. So, to achieve the entire airplane in a internally consistent model, I cut the half span down to thirds using three models to approximate taper washout and tip efficiency loss (all of these are consolidated externally in spreadsheets with corrections incorporated there).

 

I modeled multifoils using the LS1 airfoil digitized directly from the hotwire templates in my set of plans. This is overlain in the plot below where the hotwire template is black and the coords used in Javafoil are in red. This figure is from my paper, part 1, that I linked previously. The black square Cp’s are from wind tunnel measurements on the same airfoil at Re=1 e6.  BTW in this comparison, I am using the same relative coords that I sent to you, except below I have scaled it to unit chord in order to compare apples to apples.

 

Cheers,

Jay

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Michael Dunning
Sent: Thursday, March 10, 2022 7:06 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Preliminary analysis of aerodynamics of sparrow strainers (or not)

 

Funny; I had that same thought after I went to bed...

However, I used the coordinates from Jay's stock LS(1) airfoil file directly with no changes...except one: re-scaling them up to a unit chord on import. I noticed that both the files without the sparrow strainer ended at x = 0.7116. I figured that the one with the sparrow strainer was at a unit chord length (x = 1.0) and the other two just had the strainer deleted. Plotting them all side by side, that doesn't look to be the case :(



I'm also a bit puzzled by Jay's references to the Eppler main wing, so it probably has something to do with tweaks needed for his modeling framework. I'm starting to lean towards this discrepancy stemming from differences in reference chord length. This sort of thing is how I learned about 'Reynold's Number' vs. 'Reynold's Number per foot' the hard way.

We'll just have to wait for Jay to get back.
--
-MD
#2827 (still thinking about planning on visualizing how to finish building)


Re: Preliminary analysis of aerodynamics of sparrow strainers (or not)

Michael Dunning
 

Funny; I had that same thought after I went to bed...

However, I used the coordinates from Jay's stock LS(1) airfoil file directly with no changes...except one: re-scaling them up to a unit chord on import. I noticed that both the files without the sparrow strainer ended at x = 0.7116. I figured that the one with the sparrow strainer was at a unit chord length (x = 1.0) and the other two just had the strainer deleted. Plotting them all side by side, that doesn't look to be the case :(



I'm also a bit puzzled by Jay's references to the Eppler main wing, so it probably has something to do with tweaks needed for his modeling framework. I'm starting to lean towards this discrepancy stemming from differences in reference chord length. This sort of thing is how I learned about 'Reynold's Number' vs. 'Reynold's Number per foot' the hard way.

We'll just have to wait for Jay to get back.
--
-MD
#2827 (still thinking about planning on visualizing how to finish building)


Re: Quickie insurance

Corbin <c_geiser@...>
 

I was lucky in that my TW CFII worked for a company that has insurance to cover any plane he flies. By the time we ferried my Q home it gave him the 10 hours required by my insurance to instruct/transition me. I was willing to pay the price to “create” that CFII and have since let him fly the plane so that he has over 30 hours experience.

Since then, I “created” another CFII by paying to get him over the 10 hour minimum.

One of them is also a A&P and does my conditional inspections.

Like I said. I was lucky. Of course it cost me $$ to make all that work.

Corbin

On Mar 10, 2022, at 7:30 PM, Troy Zawlacki <troyzc3@...> wrote:

Does anyone have recommendations on insurance options for the Q aircraft? The responses I am getting dont look promising and require things like 20 hrs of dual from a CFI who has 10 hrs in a Q (basically impossible). Is everyone just flying without hull insurance for the first 100 hrs? Or do we just realize that hull insurance isn’t worth it for a plane with an upper end value of 30k? Ive never owned before so this is all new to me.

Taz



--
Corbin
N121CG


Quickie insurance

Troy Zawlacki
 

Does anyone have recommendations on insurance options for the Q aircraft? The responses I am getting dont look promising and require things like 20 hrs of dual from a CFI who has 10 hrs in a Q (basically impossible). Is everyone just flying without hull insurance for the first 100 hrs? Or do we just realize that hull insurance isn’t worth it for a plane with an upper end value of 30k? Ive never owned before so this is all new to me.

Taz


Re: Preliminary analysis of aerodynamics of sparrow strainers (or not)

David J. Gall
 

Michael,

Fun history tangent noted.

Regarding your reported airfoil discrepancies, is it possible that you are inadvertently comparing two different airfoils, the LS(1)-0417 from the NASA TM against the LS(1)-0417MOD that’s used on the Q200? That might explain the differences in location of maximum thickness, etc. 


David J. Gall

On Mar 8, 2022, at 10:54 PM, Jay Scheevel <jay@...> wrote:

Hi Michael,

Not much time to fully absorb all the items you bring up, but let me hit a couple. Airfoil dimensions were normalized for my multifoil model representation including with the Eppler main wing so absolute chord equal to 1.0 (100%) is reduced for dimensional convenience to accommodate both airfoils and total lift calls. This changes Reynolds numbers slightly as well. So I am just comparing apples to apples within my  personal modeling framework.

 The difference in Angle of LS1 in the QAC  plans relative to the UIUC database was noted and discussed (in addition to actual wind tunnel data) in part 1 of the Q2xx modeling paper that I did. Have a look at that summary and see if it it squares up the discrepancy you observed. 

I am headed out of town for a week or so and I will see if I can wrap my head around the other points you make as time permits. Thanks for your inputs.

Cheers,
Jay 


On Mar 8, 2022, at 9:50 PM, Michael Dunning <dunningme@...> wrote:

David,

The comment was strictly about the tailoring of the hinge moment. The rest was a fun history tangent.

Jay,

I noted a couple concerns in the provided LS(1) airfoil after running through the usual XFOIL file conversion hoops (remove tab delimiters, normalize the X/Y scale). While the max thickness is recovered correctly, the max thickness location, max camber and max camber location are considerably off from the published numbers:
<dummyfile.0.part>


Airfoil Tools (untrusted)
<dummyfile.1.part>


NASA TM-X-72843 (trusted, usually)
<dummyfile.2.part>


Regardless of that, my initial results at 2 degrees angle of attack are off in all respects from the first JavaFoil result you posted when using your (normalized) coordinates:

<dummyfile.3.part>


The two tools are never going to match but I do expect them to generally agree. My XFOIL results for zero lift AoA and where cl = 0.461 occurs are in line with the Airfoil Tools published numbers at RE=1M and the NASA published wind tunnel data, so I feel confident ruling out gross user error with the tool at least. The wind tunnel data in Figure 6 (PDF pg 28) is in general agreement and even the XFOIL over-prediction of max lift occurs at the typical +15%...and max lift AoA prediction is closer than usual at 15 vs 16 degrees actual.

Both my initial checks, the Airfoil Tools plot, and the NASA report show any cl < about 0.5 occurring at negative angles of attack. I'm doubtful but possibly this is due to the plans-template-level-line vs. chord line references? Again, not sure how JavaFoil works.
<dummyfile.4.part>


In the meantime, I need to stop and calibrate XFOIL with the wind tunnel data from the NASA report before I can be of any further use to you:
NASA-TM-X-72843 "Effects of thickness on the aerodynamic characteristics of an initial low-speed family of airfoils for general aviation applications"

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


Re: Preliminary analysis of aerodynamics of sparrow strainers (or not)

Jay Scheevel
 

Hi Michael,

Not much time to fully absorb all the items you bring up, but let me hit a couple. Airfoil dimensions were normalized for my multifoil model representation including with the Eppler main wing so absolute chord equal to 1.0 (100%) is reduced for dimensional convenience to accommodate both airfoils and total lift calls. This changes Reynolds numbers slightly as well. So I am just comparing apples to apples within my  personal modeling framework.

 The difference in Angle of LS1 in the QAC  plans relative to the UIUC database was noted and discussed (in addition to actual wind tunnel data) in part 1 of the Q2xx modeling paper that I did. Have a look at that summary and see if it it squares up the discrepancy you observed. 

I am headed out of town for a week or so and I will see if I can wrap my head around the other points you make as time permits. Thanks for your inputs.

Cheers,
Jay 


On Mar 8, 2022, at 9:50 PM, Michael Dunning <dunningme@...> wrote:

David,

The comment was strictly about the tailoring of the hinge moment. The rest was a fun history tangent.

Jay,

I noted a couple concerns in the provided LS(1) airfoil after running through the usual XFOIL file conversion hoops (remove tab delimiters, normalize the X/Y scale). While the max thickness is recovered correctly, the max thickness location, max camber and max camber location are considerably off from the published numbers:


Airfoil Tools (untrusted)


NASA TM-X-72843 (trusted, usually)


Regardless of that, my initial results at 2 degrees angle of attack are off in all respects from the first JavaFoil result you posted when using your (normalized) coordinates:



The two tools are never going to match but I do expect them to generally agree. My XFOIL results for zero lift AoA and where cl = 0.461 occurs are in line with the Airfoil Tools published numbers at RE=1M and the NASA published wind tunnel data, so I feel confident ruling out gross user error with the tool at least. The wind tunnel data in Figure 6 (PDF pg 28) is in general agreement and even the XFOIL over-prediction of max lift occurs at the typical +15%...and max lift AoA prediction is closer than usual at 15 vs 16 degrees actual.

Both my initial checks, the Airfoil Tools plot, and the NASA report show any cl < about 0.5 occurring at negative angles of attack. I'm doubtful but possibly this is due to the plans-template-level-line vs. chord line references? Again, not sure how JavaFoil works.


In the meantime, I need to stop and calibrate XFOIL with the wind tunnel data from the NASA report before I can be of any further use to you:
NASA-TM-X-72843 "Effects of thickness on the aerodynamic characteristics of an initial low-speed family of airfoils for general aviation applications"

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

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