Ground AoA/ tailwheel angle


Troy Zawlacki
 

Q-pilots,

I have a question about the ground angle of attack note in the Q2 appendix "plans changes.” The note calls for setting WL15 level, and measuring from the ground to the bottom of the tailwheel. It gives a recommended range of 25-28.6” for this measurement.

I am well versed in the Gall wheel alignment, and have just completed that on my plane. I am also pretty sure this note pre-dates the issues that were solved with the Gall alignment, but the Gall paper also doesn’t give an adjusted range for this tailwheel measurement.. There must still be a range right?

Plus, too much AoA on the ground would mean more drag during takeoff and longer runway required right?

Sam,

I read your blog post about changing your tailwheel angle back shallower for reduced drag (and since you have a proper alignment now). Do you have any idea what this measurement ended up being on your plane (ground to wheel)? My plane right now with the tail spring sitting in what looks right (parallel to top fuselage shell) has a measurement of 33” or 4.5” higher than the plans note.

I’m excited to hear some thoughts on this before I bond my tail spring in.

TAZ


Troy Zawlacki
 

Well I guess I can interpret this as nobody really having a strong opinion on the topic. I’ll proceed with my setup and my ground aoa at 11 degrees and see how she goes!

TAZ

On Jan 4, 2022, at 10:04 PM, Troy Zawlacki <troyzc3@gmail.com> wrote:

Q-pilots,

I have a question about the ground angle of attack note in the Q2 appendix "plans changes.” The note calls for setting WL15 level, and measuring from the ground to the bottom of the tailwheel. It gives a recommended range of 25-28.6” for this measurement.

I am well versed in the Gall wheel alignment, and have just completed that on my plane. I am also pretty sure this note pre-dates the issues that were solved with the Gall alignment, but the Gall paper also doesn’t give an adjusted range for this tailwheel measurement.. There must still be a range right?

Plus, too much AoA on the ground would mean more drag during takeoff and longer runway required right?

Sam,

I read your blog post about changing your tailwheel angle back shallower for reduced drag (and since you have a proper alignment now). Do you have any idea what this measurement ended up being on your plane (ground to wheel)? My plane right now with the tail spring sitting in what looks right (parallel to top fuselage shell) has a measurement of 33” or 4.5” higher than the plans note.

I’m excited to hear some thoughts on this before I bond my tail spring in.

TAZ


Bruce Crain
 

Problem is it has been a long time for lots of us from the time we went through this mod.  There are a lot of variables with respect to ground handling.  The Gall alignment,  bell crank that Jim Pattilo has on his Q200, differential braking with the rudder pedals or only having one "Johnson Bar" brake or two finger pull brakes with differential braking.  Several ways to improve the ground handling of which angle of attack is one of them.  I did what you are looking at plus I added a large non pneumatic tail wheel which helped.  Also the reflexor attached to the ailerons helps as well.  I converted mine to a TriQ 200 but flew as a Q200 for a while.  Tri Q is a different animal for ground control but slows it down a bit.  
You can do all of them if you like but many of our builders have different ideas about which one or two work best.  
You are looking the right direction to tame this bird so don't give up!  Trouble is I don't remember the numbers for degrees static.
Bruce Crain  N96BJ


---------- Original Message ----------
From: "Troy Zawlacki" <troyzc3@...>
To: "main@Q-List.groups.io Group Moderators" <main@q-list.groups.io>
Subject: Re: [Q-List] Ground AoA/ tailwheel angle
Date: Thu, 6 Jan 2022 11:10:26 -0800

Well I guess I can interpret this as nobody really having a strong opinion on the topic. I’ll proceed with my setup and my ground aoa at 11 degrees and see how she goes!

TAZ

> On Jan 4, 2022, at 10:04 PM, Troy Zawlacki <troyzc3@...> wrote:
>
> Q-pilots,
>
> I have a question about the ground angle of attack note in the Q2 appendix "plans changes.” The note calls for setting WL15 level, and measuring from the ground to the bottom of the tailwheel. It gives a recommended range of 25-28.6” for this measurement.
>
> I am well versed in the Gall wheel alignment, and have just completed that on my plane. I am also pretty sure this note pre-dates the issues that were solved with the Gall alignment, but the Gall paper also doesn’t give an adjusted range for this tailwheel measurement.. There must still be a range right?
>
> Plus, too much AoA on the ground would mean more drag during takeoff and longer runway required right?
>
> Sam,
>
> I read your blog post about changing your tailwheel angle back shallower for reduced drag (and since you have a proper alignment now). Do you have any idea what this measurement ended up being on your plane (ground to wheel)? My plane right now with the tail spring sitting in what looks right (parallel to top fuselage shell) has a measurement of 33” or 4.5” higher than the plans note.
>
> I’m excited to hear some thoughts on this before I bond my tail spring in.
>
> TAZ





Mike Steinsland
 

Hey Troy
I know that info is on the site
Search angle of incidence 
I know I found all that info before but cant remember exactly where.if I remember correctly It ties in with the angle of the firewall as well. 
I'm not at that point yet but should be in a fee months 

On Thu., Jan. 6, 2022, 2:10 p.m. Troy Zawlacki, <troyzc3@...> wrote:
Well I guess I can interpret this as nobody really having a strong opinion on the topic. I’ll proceed with my setup and my ground aoa at 11 degrees and see how she goes!

TAZ

> On Jan 4, 2022, at 10:04 PM, Troy Zawlacki <troyzc3@...> wrote:
>
> Q-pilots,
>
> I have a question about the ground angle of attack note in the Q2 appendix "plans changes.” The note calls for setting WL15 level, and measuring from the ground to the bottom of the tailwheel. It gives a recommended range of 25-28.6” for this measurement.
>
> I am well versed in the Gall wheel alignment, and have just completed that on my plane. I am also pretty sure this note pre-dates the issues that were solved with the Gall alignment, but the Gall paper also doesn’t give an adjusted range for this tailwheel measurement.. There must still be a range right?
>
> Plus, too much AoA on the ground would mean more drag during takeoff and longer runway required right?
>
> Sam,
>
> I read your blog post about changing your tailwheel angle back shallower for reduced drag (and since you have a proper alignment now). Do you have any idea what this measurement ended up being on your plane (ground to wheel)? My plane right now with the tail spring sitting in what looks right (parallel to top fuselage shell) has a measurement of 33” or 4.5” higher than the plans note.
>
> I’m excited to hear some thoughts on this before I bond my tail spring in.
>
> TAZ






Jay Scheevel
 

Hi Troy,

I am not the best person to answer your questions, since I have a tricycle gear Q2, but I did do a lot of measuring and modeling of the Q2/Q200 including lots of currently flying ones. The bottom line is that if your wings are set up so that both level lines are parallel to one another (meaning zero decalage/per plans), you should probably think about having the ground angle in the 7-8 degrees canard AOA as your starting point.

This is pretty much what the QAC plans specify. If your wings are not set up per plans, this will change what you will want, but you will have to find that out experimentally. I would suggest starting out with the 7-8 degrees, since it is the mean expectation. If you set up with 11 degrees, you will probably have your tail lift off first and land last. Generally the tail dragger people have said that they like to be close to having the tail land right after the mains or as a three point. At least that is what I have heard over the years.

There, now I have set it up so that the tail dragger pilots will correct me if I have sent you too far astray...go at it guys!

Cheers,
Jay

-----Original Message-----
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Troy Zawlacki
Sent: Thursday, January 6, 2022 12:10 PM
To: main@Q-List.groups.io Group Moderators <main@q-list.groups.io>
Subject: Re: [Q-List] Ground AoA/ tailwheel angle

Well I guess I can interpret this as nobody really having a strong opinion on the topic. I’ll proceed with my setup and my ground aoa at 11 degrees and see how she goes!

TAZ

On Jan 4, 2022, at 10:04 PM, Troy Zawlacki <troyzc3@gmail.com> wrote:

Q-pilots,

I have a question about the ground angle of attack note in the Q2 appendix "plans changes.” The note calls for setting WL15 level, and measuring from the ground to the bottom of the tailwheel. It gives a recommended range of 25-28.6” for this measurement.

I am well versed in the Gall wheel alignment, and have just completed that on my plane. I am also pretty sure this note pre-dates the issues that were solved with the Gall alignment, but the Gall paper also doesn’t give an adjusted range for this tailwheel measurement.. There must still be a range right?

Plus, too much AoA on the ground would mean more drag during takeoff and longer runway required right?

Sam,

I read your blog post about changing your tailwheel angle back shallower for reduced drag (and since you have a proper alignment now). Do you have any idea what this measurement ended up being on your plane (ground to wheel)? My plane right now with the tail spring sitting in what looks right (parallel to top fuselage shell) has a measurement of 33” or 4.5” higher than the plans note.

I’m excited to hear some thoughts on this before I bond my tail spring in.

TAZ


Mike Dwyer
 

Well, I can say that I set up my tail wheel according to the plans and it has been perfect.

The factory plane had a tail wheel like this:
I've never liked it when people use steerable ones like this for the drag penalty they pay:  
image.png  

Factory Q200 pictures:

Since we are talking about Q200 tail wheels, let me add that the tail spring size is way too small.  You need to wrap the tail spring many times with fiberglass to build it up in diameter.  Then that piece of pipe that is supposed to slide over the fiberglass tailspring - wow, way, way too small.  I had a friend (36 years ago) cut off that steel tube and weld on a much larger tube that nearly fit over the built up tailspring.  Then my next complaint is using an AN3 bolt to hold the pivot.  Total garbage.  If I was doing it now, I'd use a brass bushing with an AN4 bolt holding it.  After 1400 hours my tail wheel pivot is worn out and will have to take to a welder to fix.  It would have been nice to just press in a new brass bushing!
Mike Dwyer Q200

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


On Thu, Jan 6, 2022 at 2:58 PM Mike Steinsland <MIKESKUSTOMS@...> wrote:
Hey Troy
I know that info is on the site
Search angle of incidence 
I know I found all that info before but cant remember exactly where.if I remember correctly It ties in with the angle of the firewall as well. 
I'm not at that point yet but should be in a fee months 

On Thu., Jan. 6, 2022, 2:10 p.m. Troy Zawlacki, <troyzc3@...> wrote:
Well I guess I can interpret this as nobody really having a strong opinion on the topic. I’ll proceed with my setup and my ground aoa at 11 degrees and see how she goes!

TAZ

> On Jan 4, 2022, at 10:04 PM, Troy Zawlacki <troyzc3@...> wrote:
>
> Q-pilots,
>
> I have a question about the ground angle of attack note in the Q2 appendix "plans changes.” The note calls for setting WL15 level, and measuring from the ground to the bottom of the tailwheel. It gives a recommended range of 25-28.6” for this measurement.
>
> I am well versed in the Gall wheel alignment, and have just completed that on my plane. I am also pretty sure this note pre-dates the issues that were solved with the Gall alignment, but the Gall paper also doesn’t give an adjusted range for this tailwheel measurement.. There must still be a range right?
>
> Plus, too much AoA on the ground would mean more drag during takeoff and longer runway required right?
>
> Sam,
>
> I read your blog post about changing your tailwheel angle back shallower for reduced drag (and since you have a proper alignment now). Do you have any idea what this measurement ended up being on your plane (ground to wheel)? My plane right now with the tail spring sitting in what looks right (parallel to top fuselage shell) has a measurement of 33” or 4.5” higher than the plans note.
>
> I’m excited to hear some thoughts on this before I bond my tail spring in.
>
> TAZ






Jay Scheevel
 

Hi Troy,

Here is Mike’s airplane’s set up with respect to the Canard AOA at takeoff (first image) and landing (second image) 😉

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Mike Dwyer
Sent: Thursday, January 6, 2022 1:31 PM
To: main@q-list.groups.io
Subject: Re: [Q-List] Ground AoA/ tailwheel angle

 

Well, I can say that I set up my tail wheel according to the plans and it has been perfect.

 

The factory plane had a tail wheel like this:

I've never liked it when people use steerable ones like this for the drag penalty they pay:  

  

 

Factory Q200 pictures:

 

Since we are talking about Q200 tail wheels, let me add that the tail spring size is way too small.  You need to wrap the tail spring many times with fiberglass to build it up in diameter.  Then that piece of pipe that is supposed to slide over the fiberglass tailspring - wow, way, way too small.  I had a friend (36 years ago) cut off that steel tube and weld on a much larger tube that nearly fit over the built up tailspring.  Then my next complaint is using an AN3 bolt to hold the pivot.  Total garbage.  If I was doing it now, I'd use a brass bushing with an AN4 bolt holding it.  After 1400 hours my tail wheel pivot is worn out and will have to take to a welder to fix.  It would have been nice to just press in a new brass bushing!

Mike Dwyer Q200

 

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

 

 

On Thu, Jan 6, 2022 at 2:58 PM Mike Steinsland <MIKESKUSTOMS@...> wrote:

Hey Troy

I know that info is on the site

Search angle of incidence 

I know I found all that info before but cant remember exactly where.if I remember correctly It ties in with the angle of the firewall as well. 

I'm not at that point yet but should be in a fee months 

 

On Thu., Jan. 6, 2022, 2:10 p.m. Troy Zawlacki, <troyzc3@...> wrote:

Well I guess I can interpret this as nobody really having a strong opinion on the topic. I’ll proceed with my setup and my ground aoa at 11 degrees and see how she goes!

TAZ

> On Jan 4, 2022, at 10:04 PM, Troy Zawlacki <troyzc3@...> wrote:
>
> Q-pilots,
>
> I have a question about the ground angle of attack note in the Q2 appendix "plans changes.” The note calls for setting WL15 level, and measuring from the ground to the bottom of the tailwheel. It gives a recommended range of 25-28.6” for this measurement.
>
> I am well versed in the Gall wheel alignment, and have just completed that on my plane. I am also pretty sure this note pre-dates the issues that were solved with the Gall alignment, but the Gall paper also doesn’t give an adjusted range for this tailwheel measurement.. There must still be a range right?
>
> Plus, too much AoA on the ground would mean more drag during takeoff and longer runway required right?
>
> Sam,
>
> I read your blog post about changing your tailwheel angle back shallower for reduced drag (and since you have a proper alignment now). Do you have any idea what this measurement ended up being on your plane (ground to wheel)? My plane right now with the tail spring sitting in what looks right (parallel to top fuselage shell) has a measurement of 33” or 4.5” higher than the plans note.
>
> I’m excited to hear some thoughts on this before I bond my tail spring in.
>
> TAZ





Jim Patillo
 

Troy,

With the tail wheel on the ground and an inclinometer on the firewall


From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Bruce Crain <jcrain2@...>
Sent: Thursday, January 6, 2022 11:28:08 AM
To: main@Q-List.groups.io <main@Q-List.groups.io>
Subject: Re: [Q-List] Ground AoA/ tailwheel angle
 
Problem is it has been a long time for lots of us from the time we went through this mod.  There are a lot of variables with respect to ground handling.  The Gall alignment,  bell crank that Jim Pattilo has on his Q200, differential braking with the rudder pedals or only having one "Johnson Bar" brake or two finger pull brakes with differential braking.  Several ways to improve the ground handling of which angle of attack is one of them.  I did what you are looking at plus I added a large non pneumatic tail wheel which helped.  Also the reflexor attached to the ailerons helps as well.  I converted mine to a TriQ 200 but flew as a Q200 for a while.  Tri Q is a different animal for ground control but slows it down a bit.  
You can do all of them if you like but many of our builders have different ideas about which one or two work best.  
You are looking the right direction to tame this bird so don't give up!  Trouble is I don't remember the numbers for degrees static.
Bruce Crain  N96BJ


---------- Original Message ----------
From: "Troy Zawlacki" <troyzc3@...>
To: "main@Q-List.groups.io Group Moderators" <main@q-list.groups.io>
Subject: Re: [Q-List] Ground AoA/ tailwheel angle
Date: Thu, 6 Jan 2022 11:10:26 -0800

Well I guess I can interpret this as nobody really having a strong opinion on the topic. I’ll proceed with my setup and my ground aoa at 11 degrees and see how she goes!

TAZ

> On Jan 4, 2022, at 10:04 PM, Troy Zawlacki <troyzc3@...> wrote:
>
> Q-pilots,
>
> I have a question about the ground angle of attack note in the Q2 appendix "plans changes.” The note calls for setting WL15 level, and measuring from the ground to the bottom of the tailwheel. It gives a recommended range of 25-28.6” for this measurement.
>
> I am well versed in the Gall wheel alignment, and have just completed that on my plane. I am also pretty sure this note pre-dates the issues that were solved with the Gall alignment, but the Gall paper also doesn’t give an adjusted range for this tailwheel measurement.. There must still be a range right?
>
> Plus, too much AoA on the ground would mean more drag during takeoff and longer runway required right?
>
> Sam,
>
> I read your blog post about changing your tailwheel angle back shallower for reduced drag (and since you have a proper alignment now). Do you have any idea what this measurement ended up being on your plane (ground to wheel)? My plane right now with the tail spring sitting in what looks right (parallel to top fuselage shell) has a measurement of 33” or 4.5” higher than the plans note.
>
> I’m excited to hear some thoughts on this before I bond my tail spring in.
>
> TAZ





Jay Scheevel
 

Here is the factory prototype Q200 with a measurement on the firewall like Jim is suggesting (8 degrees from vertical).

 

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Jim Patillo
Sent: Thursday, January 6, 2022 1:40 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Ground AoA/ tailwheel angle

 

Troy,

 

With the tail wheel on the ground and an inclinometer on the firewall


From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Bruce Crain <jcrain2@...>
Sent: Thursday, January 6, 2022 11:28:08 AM
To: main@Q-List.groups.io <main@Q-List.groups.io>
Subject: Re: [Q-List] Ground AoA/ tailwheel angle

 

Problem is it has been a long time for lots of us from the time we went through this mod.  There are a lot of variables with respect to ground handling.  The Gall alignment,  bell crank that Jim Pattilo has on his Q200, differential braking with the rudder pedals or only having one "Johnson Bar" brake or two finger pull brakes with differential braking.  Several ways to improve the ground handling of which angle of attack is one of them.  I did what you are looking at plus I added a large non pneumatic tail wheel which helped.  Also the reflexor attached to the ailerons helps as well.  I converted mine to a TriQ 200 but flew as a Q200 for a while.  Tri Q is a different animal for ground control but slows it down a bit.  

You can do all of them if you like but many of our builders have different ideas about which one or two work best.  

You are looking the right direction to tame this bird so don't give up!  Trouble is I don't remember the numbers for degrees static.

Bruce Crain  N96BJ



---------- Original Message ----------
From: "Troy Zawlacki" <troyzc3@...>
To: "main@Q-List.groups.io Group Moderators" <main@q-list.groups.io>
Subject: Re: [Q-List] Ground AoA/ tailwheel angle
Date: Thu, 6 Jan 2022 11:10:26 -0800

Well I guess I can interpret this as nobody really having a strong opinion on the topic. I’ll proceed with my setup and my ground aoa at 11 degrees and see how she goes!

TAZ

> On Jan 4, 2022, at 10:04 PM, Troy Zawlacki <troyzc3@...> wrote:
>
> Q-pilots,
>
> I have a question about the ground angle of attack note in the Q2 appendix "plans changes.” The note calls for setting WL15 level, and measuring from the ground to the bottom of the tailwheel. It gives a recommended range of 25-28.6” for this measurement.
>
> I am well versed in the Gall wheel alignment, and have just completed that on my plane. I am also pretty sure this note pre-dates the issues that were solved with the Gall alignment, but the Gall paper also doesn’t give an adjusted range for this tailwheel measurement.. There must still be a range right?
>
> Plus, too much AoA on the ground would mean more drag during takeoff and longer runway required right?
>
> Sam,
>
> I read your blog post about changing your tailwheel angle back shallower for reduced drag (and since you have a proper alignment now). Do you have any idea what this measurement ended up being on your plane (ground to wheel)? My plane right now with the tail spring sitting in what looks right (parallel to top fuselage shell) has a measurement of 33” or 4.5” higher than the plans note.
>
> I’m excited to hear some thoughts on this before I bond my tail spring in.
>
> TAZ

 


Jim Patillo
 

Sorry about that. With the tail wheel on the ground and an inclinometer on the original canard template provided, the angle of incidence should be between 7.5 and 8 degrees for the canard. Presuming LS1 canard, if I remember correctly. My LS1 is mounted into the fuselage with 0 angle of incidence. 

Jim Patillo
N46JP O200
1830 hours 


From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Bruce Crain <jcrain2@...>
Sent: Thursday, January 6, 2022 11:28:08 AM
To: main@Q-List.groups.io <main@Q-List.groups.io>
Subject: Re: [Q-List] Ground AoA/ tailwheel angle
 
Problem is it has been a long time for lots of us from the time we went through this mod.  There are a lot of variables with respect to ground handling.  The Gall alignment,  bell crank that Jim Pattilo has on his Q200, differential braking with the rudder pedals or only having one "Johnson Bar" brake or two finger pull brakes with differential braking.  Several ways to improve the ground handling of which angle of attack is one of them.  I did what you are looking at plus I added a large non pneumatic tail wheel which helped.  Also the reflexor attached to the ailerons helps as well.  I converted mine to a TriQ 200 but flew as a Q200 for a while.  Tri Q is a different animal for ground control but slows it down a bit.  
You can do all of them if you like but many of our builders have different ideas about which one or two work best.  
You are looking the right direction to tame this bird so don't give up!  Trouble is I don't remember the numbers for degrees static.
Bruce Crain  N96BJ


---------- Original Message ----------
From: "Troy Zawlacki" <troyzc3@...>
To: "main@Q-List.groups.io Group Moderators" <main@q-list.groups.io>
Subject: Re: [Q-List] Ground AoA/ tailwheel angle
Date: Thu, 6 Jan 2022 11:10:26 -0800

Well I guess I can interpret this as nobody really having a strong opinion on the topic. I’ll proceed with my setup and my ground aoa at 11 degrees and see how she goes!

TAZ

> On Jan 4, 2022, at 10:04 PM, Troy Zawlacki <troyzc3@...> wrote:
>
> Q-pilots,
>
> I have a question about the ground angle of attack note in the Q2 appendix "plans changes.” The note calls for setting WL15 level, and measuring from the ground to the bottom of the tailwheel. It gives a recommended range of 25-28.6” for this measurement.
>
> I am well versed in the Gall wheel alignment, and have just completed that on my plane. I am also pretty sure this note pre-dates the issues that were solved with the Gall alignment, but the Gall paper also doesn’t give an adjusted range for this tailwheel measurement.. There must still be a range right?
>
> Plus, too much AoA on the ground would mean more drag during takeoff and longer runway required right?
>
> Sam,
>
> I read your blog post about changing your tailwheel angle back shallower for reduced drag (and since you have a proper alignment now). Do you have any idea what this measurement ended up being on your plane (ground to wheel)? My plane right now with the tail spring sitting in what looks right (parallel to top fuselage shell) has a measurement of 33” or 4.5” higher than the plans note.
>
> I’m excited to hear some thoughts on this before I bond my tail spring in.
>
> TAZ





Sam Hoskins
 

Troy , I have to apologize. I was heading out to the hangar for a few things and I meant to measure my deck angle, that is, the angle on top of the fuselage just aft of the firewall.

I forgot.

I don't know how important it is with a tail dragger, really.  For me the main thing is to be able to see over the engine on rollout.  And for that, my tail spring is pretty muck in line with the fuselage.  Like this: https://q-list.groups.io/g/main/photo/115659/1394126?p=Created%2C%2C%2C100%2C2%2C0%2C0

Sam

On Wed, Jan 5, 2022 at 12:04 AM Troy Zawlacki <troyzc3@...> wrote:
Q-pilots,

I have a question about the ground angle of attack note in the Q2 appendix "plans changes.” The note calls for setting WL15 level, and measuring from the ground to the bottom of the tailwheel. It gives a recommended range of 25-28.6” for this measurement.

I am well versed in the Gall wheel alignment, and have just completed that on my plane. I am also pretty sure this note pre-dates the issues that were solved with the Gall alignment, but the Gall paper also doesn’t give an adjusted range for this tailwheel measurement.. There must still be a range right?

Plus, too much AoA on the ground would mean more drag during takeoff and longer runway required right?

Sam,

I read your blog post about changing your tailwheel angle back shallower for reduced drag (and since you have a proper alignment now). Do you have any idea what this measurement ended up being on your plane (ground to wheel)? My plane right now with the tail spring sitting in what looks right (parallel to top fuselage shell) has a measurement of 33” or 4.5” higher than the plans note.

I’m excited to hear some thoughts on this before I bond my tail spring in.

TAZ





Frankenbird Vern
 

 This is in my build log also. My tailwheel spring is round steel..arc to meet the 8 degree ramp angle. I may end up 
setting a bit more arc since the MKII gear I have in works is more as the RV6..or Tailwind.  In any case my target is 8 
degrees as Jay provides here.      


From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Jay Scheevel <jay@...>
Sent: Thursday, January 6, 2022 2:42 PM
To: main@Q-List.groups.io <main@Q-List.groups.io>
Subject: Re: [Q-List] Ground AoA/ tailwheel angle
 

Here is the factory prototype Q200 with a measurement on the firewall like Jim is suggesting (8 degrees from vertical).

 

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Jim Patillo
Sent: Thursday, January 6, 2022 1:40 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Ground AoA/ tailwheel angle

 

Troy,

 

With the tail wheel on the ground and an inclinometer on the firewall


From: main@Q-List.groups.io <main@Q-List.groups.io> on behalf of Bruce Crain <jcrain2@...>
Sent: Thursday, January 6, 2022 11:28:08 AM
To: main@Q-List.groups.io <main@Q-List.groups.io>
Subject: Re: [Q-List] Ground AoA/ tailwheel angle

 

Problem is it has been a long time for lots of us from the time we went through this mod.  There are a lot of variables with respect to ground handling.  The Gall alignment,  bell crank that Jim Pattilo has on his Q200, differential braking with the rudder pedals or only having one "Johnson Bar" brake or two finger pull brakes with differential braking.  Several ways to improve the ground handling of which angle of attack is one of them.  I did what you are looking at plus I added a large non pneumatic tail wheel which helped.  Also the reflexor attached to the ailerons helps as well.  I converted mine to a TriQ 200 but flew as a Q200 for a while.  Tri Q is a different animal for ground control but slows it down a bit.  

You can do all of them if you like but many of our builders have different ideas about which one or two work best.  

You are looking the right direction to tame this bird so don't give up!  Trouble is I don't remember the numbers for degrees static.

Bruce Crain  N96BJ



---------- Original Message ----------
From: "Troy Zawlacki" <troyzc3@...>
To: "main@Q-List.groups.io Group Moderators" <main@q-list.groups.io>
Subject: Re: [Q-List] Ground AoA/ tailwheel angle
Date: Thu, 6 Jan 2022 11:10:26 -0800

Well I guess I can interpret this as nobody really having a strong opinion on the topic. I’ll proceed with my setup and my ground aoa at 11 degrees and see how she goes!

TAZ

> On Jan 4, 2022, at 10:04 PM, Troy Zawlacki <troyzc3@...> wrote:
>
> Q-pilots,
>
> I have a question about the ground angle of attack note in the Q2 appendix "plans changes.” The note calls for setting WL15 level, and measuring from the ground to the bottom of the tailwheel. It gives a recommended range of 25-28.6” for this measurement.
>
> I am well versed in the Gall wheel alignment, and have just completed that on my plane. I am also pretty sure this note pre-dates the issues that were solved with the Gall alignment, but the Gall paper also doesn’t give an adjusted range for this tailwheel measurement.. There must still be a range right?
>
> Plus, too much AoA on the ground would mean more drag during takeoff and longer runway required right?
>
> Sam,
>
> I read your blog post about changing your tailwheel angle back shallower for reduced drag (and since you have a proper alignment now). Do you have any idea what this measurement ended up being on your plane (ground to wheel)? My plane right now with the tail spring sitting in what looks right (parallel to top fuselage shell) has a measurement of 33” or 4.5” higher than the plans note.
>
> I’m excited to hear some thoughts on this before I bond my tail spring in.
>
> TAZ

 


David J. Gall
 

TAZ,

Do the Jim-Bob six-pack (all six), do the alignment, and don't worry about the "ground angle of attack." That was a Gene Sheehan red herring that never made any sense except to deflect customer complaints. As long as your nose isn’t so high in the air as to cause the canard to be stalled while rolling with full aft stick you'll be fine.


David J. Gall

-----Original Message-----
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Troy Zawlacki
Sent: Thursday, January 6, 2022 11:10 AM
To: main@Q-List.groups.io Group Moderators <main@q-list.groups.io>
Subject: Re: [Q-List] Ground AoA/ tailwheel angle

Well I guess I can interpret this as nobody really having a strong opinion on the topic. I’ll proceed with my setup and my ground aoa at 11 degrees and see how she goes!

TAZ

On Jan 4, 2022, at 10:04 PM, Troy Zawlacki <troyzc3@gmail.com> wrote:

Q-pilots,

I have a question about the ground angle of attack note in the Q2 appendix "plans changes.” The note calls for setting WL15 level, and measuring from the ground to the bottom of the tailwheel. It gives a recommended range of 25-28.6” for this measurement.

I am well versed in the Gall wheel alignment, and have just completed that on my plane. I am also pretty sure this note pre-dates the issues that were solved with the Gall alignment, but the Gall paper also doesn’t give an adjusted range for this tailwheel measurement.. There must still be a range right?

Plus, too much AoA on the ground would mean more drag during takeoff and longer runway required right?

Sam,

I read your blog post about changing your tailwheel angle back shallower for reduced drag (and since you have a proper alignment now). Do you have any idea what this measurement ended up being on your plane (ground to wheel)? My plane right now with the tail spring sitting in what looks right (parallel to top fuselage shell) has a measurement of 33” or 4.5” higher than the plans note.

I’m excited to hear some thoughts on this before I bond my tail spring in.

TAZ


Martin Skiby
 

Follow David Gall’s advice here. It works.

Martin

On Jan 6, 2022, at 3:59 PM, David J. Gall <David@gall.com> wrote:

TAZ,

Do the Jim-Bob six-pack (all six), do the alignment, and don't worry about the "ground angle of attack." That was a Gene Sheehan red herring that never made any sense except to deflect customer complaints. As long as your nose isn’t so high in the air as to cause the canard to be stalled while rolling with full aft stick you'll be fine.


David J. Gall


-----Original Message-----
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Troy Zawlacki
Sent: Thursday, January 6, 2022 11:10 AM
To: main@Q-List.groups.io Group Moderators <main@q-list.groups.io>
Subject: Re: [Q-List] Ground AoA/ tailwheel angle

Well I guess I can interpret this as nobody really having a strong opinion on the topic. I’ll proceed with my setup and my ground aoa at 11 degrees and see how she goes!

TAZ

On Jan 4, 2022, at 10:04 PM, Troy Zawlacki <troyzc3@gmail.com> wrote:

Q-pilots,

I have a question about the ground angle of attack note in the Q2 appendix "plans changes.” The note calls for setting WL15 level, and measuring from the ground to the bottom of the tailwheel. It gives a recommended range of 25-28.6” for this measurement.

I am well versed in the Gall wheel alignment, and have just completed that on my plane. I am also pretty sure this note pre-dates the issues that were solved with the Gall alignment, but the Gall paper also doesn’t give an adjusted range for this tailwheel measurement.. There must still be a range right?

Plus, too much AoA on the ground would mean more drag during takeoff and longer runway required right?

Sam,

I read your blog post about changing your tailwheel angle back shallower for reduced drag (and since you have a proper alignment now). Do you have any idea what this measurement ended up being on your plane (ground to wheel)? My plane right now with the tail spring sitting in what looks right (parallel to top fuselage shell) has a measurement of 33” or 4.5” higher than the plans note.

I’m excited to hear some thoughts on this before I bond my tail spring in.

TAZ










Troy Zawlacki
 

Thank you all for the input on this. I have read various different opinions online but there is no better source than a seasoned group of pilots. 

My canard (LS1) was purchased by the previous owner of this kit back in the 80s from a company called Quality Aircraft Components (QAC, suspicious right?). For whatever reason, the anhedral angle is a little steeper than the plans, so I knew my plane would sit taller in the front than most, which is what led me to asking the question in the first place. 

Thank you again for chiming in, now I feel comfortable to proceed and mount the tail spring.

TAZ

On Jan 6, 2022, at 3:08 PM, Martin Skiby <mskiby@...> wrote:

Follow David Gall’s advice here.   It works.

Martin
On Jan 6, 2022, at 3:59 PM, David J. Gall <David@...> wrote:

TAZ,

Do the Jim-Bob six-pack (all six), do the alignment, and don't worry about the "ground angle of attack." That was a Gene Sheehan red herring that never made any sense except to deflect customer complaints. As long as your nose isn’t so high in the air as to cause the canard to be stalled while rolling with full aft stick you'll be fine.


David J. Gall


-----Original Message-----
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Troy Zawlacki
Sent: Thursday, January 6, 2022 11:10 AM
To: main@Q-List.groups.io Group Moderators <main@q-list.groups.io>
Subject: Re: [Q-List] Ground AoA/ tailwheel angle

Well I guess I can interpret this as nobody really having a strong opinion on the topic. I’ll proceed with my setup and my ground aoa at 11 degrees and see how she goes!

TAZ

On Jan 4, 2022, at 10:04 PM, Troy Zawlacki <troyzc3@...> wrote:

Q-pilots,

I have a question about the ground angle of attack note in the Q2 appendix "plans changes.” The note calls for setting WL15 level, and measuring from the ground to the bottom of the tailwheel. It gives a recommended range of 25-28.6” for this measurement. 

I am well versed in the Gall wheel alignment, and have just completed that on my plane. I am also pretty sure this note pre-dates the issues that were solved with the Gall alignment, but the Gall paper also doesn’t give an adjusted range for this tailwheel measurement.. There must still be a range right?

Plus, too much AoA on the ground would mean more drag during takeoff and longer runway required right?

Sam, 

I read your blog post about changing your tailwheel angle back shallower for reduced drag (and since you have a proper alignment now). Do you have any idea what this measurement ended up being on your plane (ground to wheel)? My plane right now with the tail spring sitting in what looks right (parallel to top fuselage shell) has a measurement of 33” or 4.5” higher than the plans note.

I’m excited to hear some thoughts on this before I bond my tail spring in.

TAZ
















Chris Walterson
 

Troy------- I am probably wrong , but I  think somewhere  i read that the angle is 7.5---8.5.  I had sent a few pictures of my airplane to Jay and he did the check for angle and I came out where I should be.  I have only flow it twice , but it seems good.

 Sometimes " lucky" is better than smart.-----------  Chris


--
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Jay Scheevel
 

Did a quick survey of the planes I have measured over the years. These are all tail-draggers that have been flying for years, most of them decades (not attaching names/N-numbers to protect the innocent):

Degrees ground angle (unloaded)
8.97
8.84
7.8
8.98
7.95
9.36
8.1
6.5
8.35
8.5
7.5

Only a very few of these planes had zero decalage, so I averaged the MW and Canard angles to arrive at the average wing ground angle.

Also, based on 5 different planes where I had inflight videos, all aircraft including tri-gear flared and touched down between 8 and 10 degrees AOA.

Hope this helps.

Cheers,
Jay

-----Original Message-----
From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Chris Walterson
Sent: Thursday, January 6, 2022 5:15 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Ground AoA/ tailwheel angle

Troy------- I am probably wrong , but I think somewhere i read that the angle is 7.5---8.5. I had sent a few pictures of my airplane to Jay and he did the check for angle and I came out where I should be. I have only flow it twice , but it seems good.

Sometimes " lucky" is better than smart.----------- Chris


--
This email has been checked for viruses by Avast antivirus software.
https://www.avast.com/antivirus


Michael Dunning
 

Finally found the Wainfan references I was looking for; wanted to make sure I wasn't crazy before weighing in. The following is quick, back of the envelope engiNerding meant for illustrative purposes more than anything, so play along for funsies...

Aerodynamically, the best things to reduce takeoff roll are to reduce wing loading and get as close to maximum lift coefficient (Clmax) as possible. Our wings are pretty well fixed (pun intended) so that leaves us getting close to Clmax via mounting angle (angle of attack). Looking *just* at the main wing airfoil, at a close but not perfect takeoff condition since I'm lazy (Reynolds 1M vs ~800k), we see Clmax occurs ~15 degress AoA. We are a tandem wing airplane, so we can't get close to that.

So the next best thing we can do is get as much angle as possible before drag (Cd) goes straight through the roof. That appears to happen in the 10ish degree range:



A good bet here - where we can't achieve max lift - would be to maximize "lifting efficiency", or Cl/Cd for us engineer types. That appears to occur within a neat little plateau from around 10±2.5 degrees...SMACK where Jay has observed it on flying airplanes:



So basically...don't stress it too much. There's a fair bit of wiggle room, and Flying Airplanes don't lie 😉
--
-MD
#2827 (still thinking about planning on visualizing how to finish building)


David J. Gall
 

Since we’re only interested in “ground angle of attack” the analysis centers on the canard with “flap extended” (full aft stick). Set the “ground angle of attack” via the tailspring installed angle/length so that in the three-point attitude the canard can get close to its full-aft-stick CLmax to permit liftoff at minimum speed (and to be able to land at minimum touchdown speed).

 

Since the tailwheel prevents the airplane from being rotated nose-up while rolling in the three-point attitude, setting the “ground angle of attack” to a too-low pitch attitude that prevents achieving nearly CLmax will mean that the airplane will need to continue accelerating on the ground until the lower angle of attack/CL and the higher speed satisfy the lift equation to overcome gravity. Yes, it is possible that a lower ground angle of attack *might* yield less drag during acceleration so that the higher liftoff speed would be attained in a shorter distance, but who’s got the analysis horsepower for that effort? And anyway, if one thinks that to be the case, the stick also serves as a drag control on the ground – don’t pull full aft stick until close to liftoff speed.

 

Set the “ground angle of attack” the old-school way like the Piper Cub guy did, so that the “front wing” (canard) can make close to its CLmax while still in the three-point attitude and, thereby, liftoff at minimum flying speed.

 

You’ll note that I couched references to the CLmax term with a “close to” at every instance; this is so that liftoff actually occurs at something a little bit faster than stall speed. It’s no fun lifting off and climbing out of ground effect only to stall right away. About a one degree lower “ground angle of attack” margin will give a 0.1 CL margin above stall. The liftoff still happens well below (L/D)max so the initial acceleration in ground effect is on the “back side of the power curve” -- some airplanes are so draggy that the margin needs to be more than just one degree, but I think the Q2/Q200 is a fairly low-drag design, so a one degree margin below the CLmax “ground angle of attack” should be sufficient to prevent unexpected settling back onto the runway after liftoff.

 

Worth every penny you paid for it, my advice is only an opinion and I hereby declaim any and all liability for anything bad that comes of it. (Kudos and accolades for good outcomes may be expressed via copious amounts of cash, as always.)

 

 

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Michael
Sent: Friday, January 7, 2022 6:28 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Ground AoA/ tailwheel angle

 

Finally found the Wainfan references I was looking for; wanted to make sure I wasn't crazy before weighing in. The following is quick, back of the envelope engiNerding meant for illustrative purposes more than anything, so play along for funsies...

Aerodynamically, the best things to reduce takeoff roll are to reduce wing loading and get as close to maximum lift coefficient (Clmax) as possible. Our wings are pretty well fixed (pun intended) so that leaves us getting close to Clmax via mounting angle (angle of attack). Looking *just* at the main wing airfoil, at a close but not perfect takeoff condition since I'm lazy (Reynolds 1M vs ~800k), we see Clmax occurs ~15 degress AoA. We are a tandem wing airplane, so we can't get close to that.

So the next best thing we can do is get as much angle as possible before drag (Cd) goes straight through the roof. That appears to happen in the 10ish degree range:



A good bet here - where we can't achieve max lift - would be to maximize "lifting efficiency", or Cl/Cd for us engineer types. That appears to occur within a neat little plateau from around 10±2.5 degrees...SMACK where Jay has observed it on flying airplanes:



So basically...don't stress it too much. There's a fair bit of wiggle room, and Flying Airplanes don't lie 😉
--
-MD
#2827 (still thinking about planning on visualizing how to finish building)


David J. Gall
 

Mike, why are you looking at the main wing here? It’s the canard that controls liftoff speed….

 

From: main@Q-List.groups.io <main@Q-List.groups.io> On Behalf Of Michael
Sent: Friday, January 7, 2022 6:28 PM
To: main@Q-List.groups.io
Subject: Re: [Q-List] Ground AoA/ tailwheel angle

 

Finally found the Wainfan references I was looking for; wanted to make sure I wasn't crazy before weighing in. The following is quick, back of the envelope engiNerding meant for illustrative purposes more than anything, so play along for funsies...

Aerodynamically, the best things to reduce takeoff roll are to reduce wing loading and get as close to maximum lift coefficient (Clmax) as possible. Our wings are pretty well fixed (pun intended) so that leaves us getting close to Clmax via mounting angle (angle of attack). Looking *just* at the main wing airfoil, at a close but not perfect takeoff condition since I'm lazy (Reynolds 1M vs ~800k), we see Clmax occurs ~15 degress AoA. We are a tandem wing airplane, so we can't get close to that.

So the next best thing we can do is get as much angle as possible before drag (Cd) goes straight through the roof. That appears to happen in the 10ish degree range:



A good bet here - where we can't achieve max lift - would be to maximize "lifting efficiency", or Cl/Cd for us engineer types. That appears to occur within a neat little plateau from around 10±2.5 degrees...SMACK where Jay has observed it on flying airplanes:



So basically...don't stress it too much. There's a fair bit of wiggle room, and Flying Airplanes don't lie 😉
--
-MD
#2827 (still thinking about planning on visualizing how to finish building)