 |
Matronics Email Lists
Web Forum Interface to the Matronics Email Lists
|
| View previous topic :: View next topic |
| Author |
Message |
victorbravo(at)sbcglobal.
Guest
|
 Posted: Sat Aug 11, 2018 4:04 pm Post subject: Kolb-List:Stabilizer Angle |
 |
|
Per the previous discussions regarding my FS2 / HKS testing, I have raised the leading edge of the stabilizers significantly higher than they had originally been, in order to counteract the amount of stick force I had to hold to keep the nose level.
I am trying to attach photos of the modification to this e-mail.
These photos represent the mounting point 1.25 inches above the original mounting.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
| Description: |
|
| Filesize: |
161.05 KB |
| Viewed: |
16791 Time(s) |
|
| Description: |
|
| Filesize: |
94.29 KB |
| Viewed: |
16791 Time(s) |
|
| Description: |
|
| Filesize: |
160.35 KB |
| Viewed: |
16791 Time(s) |
|
| Description: |
|
| Filesize: |
161.38 KB |
| Viewed: |
16791 Time(s) |
|
| Description: |
|
| Filesize: |
77.84 KB |
| Viewed: |
16791 Time(s) |
|
|
|
| Back to top |
|
 |
lcottrell
Joined: 29 May 2006
Posts: 1494
Location: Jordan Valley, Or
|
| Posted: Sat Aug 11, 2018 4:50 pm Post subject: Kolb-List:Stabilizer Angle |
|
|
Well I am definitely not an engineer, ( thank goodness, I have enough problems as it is) but it would appear to me as though this configuration will cause the tail to fly even higher than it had before. It is substantially higher in the front than mine is. And all of this is to keep from using a trim tab on the elevator? If you will notice the bottom of the front edge of the elevator is lower than the top of the boom tube.
Mine is trimmed to fly level at 5400 RPM (WOT 6100) With it set this way, if I want to climb, I give it more throttle, I flew from my house at 3860 feet to 10,000 feet at the top of the Steen's with no input from me at 5800 RPMs, over a distance of 39 miles.
Personally I think you are running down the wrong rat hole, but that is your option.
On Sat, Aug 11, 2018 at 6:07 PM Bill Berle <victorbravo(at)sbcglobal.net (victorbravo(at)sbcglobal.net)> wrote:
| Quote: | Per the previous discussions regarding my FS2 / HKS testing, I have raised the leading edge of the stabilizers significantly higher than they had originally been, in order to counteract the amount of stick force I had to hold to keep the nose level.
I am trying to attach photos of the modification to this e-mail.
These photos represent the mounting point 1.25 inches above the original mounting.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities |
--
The older I get, the less tolerant I am of those who are intolerant of others.
If you forward this email, or any part of it, please remove my email address before sending.
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
| Description: |
|
| Filesize: |
1.19 MB |
| Viewed: |
16793 Time(s) |
|
| Description: |
|
| Filesize: |
1.22 MB |
| Viewed: |
16793 Time(s) |
|
_________________
do not archive |
|
| Back to top |
|
|
james.vanlaak(at)gmail.co
Guest
|
| Posted: Sat Aug 11, 2018 5:13 pm Post subject: Kolb-List:Stabilizer Angle |
|
|
I have to say that this does not look healthy, and I suspect your CG is not where you think it is. Remember that a normally stable airplane has the CG forward of the center of pressure which is why it flies with a download on the tail. The Kolb high mounted pusher engine also needs download on the tail. If you are so close to neutral or even an upload, that suggests poor stall/spin behavior. It might still ok in level flight, but an accelerated stall or engine out (windmilling engine pulling nose up) could be unpleasant.
Suggest you carefully re-evaluate the cg and move it forward some.
On Sat, Aug 11, 2018 at 8:04 PM, Bill Berle <victorbravo(at)sbcglobal.net (victorbravo(at)sbcglobal.net)> wrote:
| Quote: | Per the previous discussions regarding my FS2 / HKS testing, I have raised the leading edge of the stabilizers significantly higher than they had originally been, in order to counteract the amount of stick force I had to hold to keep the nose level.
I am trying to attach photos of the modification to this e-mail.
These photos represent the mounting point 1.25 inches above the original mounting.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities |
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
|
|
| Back to top |
|
|
John Hauck
Joined: 09 Jan 2006
Posts: 4639
Location: Titus, Alabama (hauck's holler)
|
| Posted: Sat Aug 11, 2018 5:37 pm Post subject: Kolb-List:Stabilizer Angle |
|
|
Jim V/Kolbers,
Makes a lot of sense to me.
john h
mkIII
Titus, Alabama
From: owner-kolb-list-server(at)matronics.com [mailto:owner-kolb-list-server(at)matronics.com] On Behalf Of james.vanlaak(at)gmail.com
Sent: Saturday, August 11, 2018 8:13 PM
To: kolb-list(at)matronics.com
Subject: Re: Kolb-List:Stabilizer Angle
I have to say that this does not look healthy, and I suspect your CG is not where you think it is. Remember that a normally stable airplane has the CG forward of the center of pressure which is why it flies with a download on the tail. The Kolb high mounted pusher engine also needs download on the tail. If you are so close to neutral or even an upload, that suggests poor stall/spin behavior. It might still ok in level flight, but an accelerated stall or engine out (windmilling engine pulling nose up) could be unpleasant.
Suggest you carefully re-evaluate the cg and move it forward some.
On Sat, Aug 11, 2018 at 8:04 PM, Bill Berle <victorbravo(at)sbcglobal.net (victorbravo(at)sbcglobal.net)> wrote:
Per the previous discussions regarding my FS2 / HKS testing, I have raised the leading edge of the stabilizers significantly higher than they had originally been, in order to counteract the amount of stick force I had to hold to keep the nose level.
I am trying to attach photos of the modification to this e-mail.
These photos represent the mounting point 1.25 inches above the original mounting.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
_________________
John Hauck
MKIII/912ULS
hauck's holler
Titus, Alabama |
|
| Back to top |
|
|
gdhelton(at)gmail.com
Guest
|
| Posted: Sat Aug 11, 2018 6:00 pm Post subject: Kolb-List:Stabilizer Angle |
|
|
Good grief! I can’t believe what I’m looking at here. I would suggest doing what John H. and Larry have suggested. I’ve never seen anything like that before on a Kolb. I’d be looking at an aft c/g problem myself. I’ve read your explanation of your c/g, Bill and with all that muffler ( yes, I know it is special to you.)hanging back there plus the weight of the HKS. It doesn’t take that much to shift the c/g to the rear. Plus your not even carrying a full load of fuel yet?
I converted my Firestar from a 377 Rotax to a 2702 Hirth this last winter. The engine weight was actually the same but the gearbox wt. is 10 lbs. more then a Rotax “B”gearbox. Plus the 3 blade 60” Powerfin prop added a additional 3 pounds more then its predecessor. I knew after the first couple of flights that I had a c/g problem. I’ve flown my Firestar long enough to recognize a major problem. I ended up making an all new engine mount to move the engine forward 2 1/2” to get the c/g back to where it belonged. I’m attaching two pictures. One is my horizontal stabilizer and other is the engine mount.
[img]cid:6943ADAD-A98B-4E6D-A9F9-21F57C0F2940[/img]
[img]cid:2D2FC27E-537B-40A7-8D25-A219A8F50482[/img]
Oh, that nice little starter was another 5 lbs. every little bit adds up. I’m not sure, but it seems like the pictures of the HKS engines that I’ve seen on Kolbs before had forward mount mufflers which seems to make sense for c/g purposes. One other thing you might check is making sure that your boom tube is the proper length. Some builders have been known to shorten them up to accommodate shorter trailers. Unscrupulous modifiers.
Anyway, this is just my thoughts. What do I know?
George H.
Firestar, FS100, 2702 Hirth
14GDH
Mesick, Michigan
gdhelton(at)gmail.com (gdhelton(at)gmail.com)
P.S. : Really is a nice looking little Firestar II.
Sent from my iPhone
On Aug 11, 2018, at 8:49 PM, Larry Cottrell <lcottrell1020(at)gmail.com (lcottrell1020(at)gmail.com)> wrote:
| Quote: | Well I am definitely not an engineer, ( thank goodness, I have enough problems as it is) but it would appear to me as though this configuration will cause the tail to fly even higher than it had before. It is substantially higher in the front than mine is. And all of this is to keep from using a trim tab on the elevator? If you will notice the bottom of the front edge of the elevator is lower than the top of the boom tube.
Mine is trimmed to fly level at 5400 RPM (WOT 6100) With it set this way, if I want to climb, I give it more throttle, I flew from my house at 3860 feet to 10,000 feet at the top of the Steen's with no input from me at 5800 RPMs, over a distance of 39 miles.
Personally I think you are running down the wrong rat hole, but that is your option.
On Sat, Aug 11, 2018 at 6:07 PM Bill Berle <victorbravo(at)sbcglobal.net (victorbravo(at)sbcglobal.net)> wrote:
| Quote: | Per the previous discussions regarding my FS2 / HKS testing, I have raised the leading edge of the stabilizers significantly higher than they had originally been, in order to counteract the amount of stick force I had to hold to keep the nose level.
I am trying to attach photos of the modification to this e-mail.
These photos represent the mounting point 1.25 inches above the original mounting.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities |
--
The older I get, the less tolerant I am of those who are intolerant of others.
If you forward this email, or any part of it, please remove my email address before sending.
<trim tab.JPG>
<elevator.JPG>
|
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
| Description: |
|
| Filesize: |
157.58 KB |
| Viewed: |
16791 Time(s) |
|
| Description: |
|
| Filesize: |
94.01 KB |
| Viewed: |
16791 Time(s) |
|
|
|
| Back to top |
|
|
John Hauck
Joined: 09 Jan 2006
Posts: 4639
Location: Titus, Alabama (hauck's holler)
|
| Posted: Sat Aug 11, 2018 6:21 pm Post subject: Kolb-List:Stabilizer Angle |
|
|
George H,
This reminds me of my initial build of my mkIII. I decided the tail boom was too long, based on flying Homer's MKIII and other Kolbs. I was going to make it a little snappier handling. I shortened by a foot. That airplane would never settle down. It felt terrible. I replaced the tail boom with the proper length and the mkIII flew like a little doll baby.
john h
mkIII
Titus, Alabama
One other thing you might check is making sure that your boom tube is the proper length. Some builders have been known to shorten them up to accommodate shorter trailers. Unscrupulous modifiers.
Anyway, this is just my thoughts. What do I know?
George H.
Firestar, FS100, 2702 Hirth
14GDH
Mesick, Michigan
gdhelton(at)gmail.com (gdhelton(at)gmail.com)
P.S. : Really is a nice looking little Firestar II.
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
_________________
John Hauck
MKIII/912ULS
hauck's holler
Titus, Alabama |
|
| Back to top |
|
|
gdhelton(at)gmail.com
Guest
|
| Posted: Sat Aug 11, 2018 6:38 pm Post subject: Kolb-List:Stabilizer Angle |
|
|
Yeah, John I had contemplated on the same thing with my Firestar when I was building it to accommodate a shorter storage space. Homer assured me that it would not serve me well. Plus it’s still the same length with the wings folded. I built it per plans. And got a longer trailer. I prefer my hanger.
George
Sent from my iPhone
On Aug 11, 2018, at 10:21 PM, John Hauck <jhauck(at)elmore.rr.com (jhauck(at)elmore.rr.com)> wrote:
| Quote: | <![endif]--> <![endif]-->
George H,
This reminds me of my initial build of my mkIII. I decided the tail boom was too long, based on flying Homer's MKIII and other Kolbs. I was going to make it a little snappier handling. I shortened by a foot. That airplane would never settle down. It felt terrible. I replaced the tail boom with the proper length and the mkIII flew like a little doll baby.
john h
mkIII
Titus, Alabama
One other thing you might check is making sure that your boom tube is the proper length. Some builders have been known to shorten them up to accommodate shorter trailers. Unscrupulous modifiers.
Anyway, this is just my thoughts. What do I know?
George H.
Firestar, FS100, 2702 Hirth
14GDH
Mesick, Michigan
gdhelton(at)gmail.com (gdhelton(at)gmail.com)
P.S. : Really is a nice looking little Firestar II.
|
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
|
|
| Back to top |
|
|
victorbravo(at)sbcglobal.
Guest
|
| Posted: Sat Aug 11, 2018 8:46 pm Post subject: Kolb-List:Stabilizer Angle |
|
|
Will review the balance numbers and report the results.
Sent from my Samsung Captivate(tm) on AT&T
james.vanlaak(at)gmail.com wrote:
| Quote: | I have to say that this does not look healthy, and I suspect your CG is not
where you think it is. Remember that a normally stable airplane has the CG
forward of the center of pressure which is why it flies with a download on
the tail. The Kolb high mounted pusher engine also needs download on the
tail. If you are so close to neutral or even an upload, that suggests poor
stall/spin behavior. It might still ok in level flight, but an accelerated
stall or engine out (windmilling engine pulling nose up) could be
unpleasant.
Suggest you carefully re-evaluate the cg and move it forward some.
On Sat, Aug 11, 2018 at 8:04 PM, Bill Berle <victorbravo(at)sbcglobal.net>
wrote:
> Per the previous discussions regarding my FS2 / HKS testing, I have raised
> the leading edge of the stabilizers significantly higher than they had
> originally been, in order to counteract the amount of stick force I had to
> hold to keep the nose level.
>
> I am trying to attach photos of the modification to this e-mail.
>
> These photos represent the mounting point 1.25 inches above the original
> mounting.
>
> Bill Berle
> www.ezflaphandle.com - safety & performance upgrade for light aircraft
> www.grantstar.net - winning proposals for non-profit and
> for-profit entities
|
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
|
|
| Back to top |
|
|
Richard Pike
Joined: 09 Jan 2006
Posts: 1671
Location: Blountville, Tennessee
|
| Posted: Sun Aug 12, 2018 4:38 am Post subject: Re: Kolb-List:Stabilizer Angle |
|
|
Looking at this thread, and then looking at my web page on raising the elevator leading edges on Ed's FSII, I just made a startling discovery; I apparently was not paying attention when I typed in the info-
I got it backwards!
http://oh2fly.net/oldpoops/FSIIelevatorbracket.html
Raising the aileron trailing edges (or flaps) moves the center of lift forward, drooping the ailerons (or flaps) moves it aft.
My apologies to everyone, I'll fix it this afternoon.
(How come none of you guys caught that? You should have had my butt on a plate a couple years ago for that one!)
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
_________________
Richard Pike
Kolb MKIII N420P (420ldPoops)
Kingsport, TN 3TN0
Forgiving is tough, being forgiven is wonderful, and God's grace really is amazing. |
|
| Back to top |
|
|
John Hauck
Joined: 09 Jan 2006
Posts: 4639
Location: Titus, Alabama (hauck's holler)
|
| Posted: Sun Aug 12, 2018 5:29 am Post subject: Kolb-List:Stabilizer Angle |
|
|
Folks with flap aircraft know when you droop the flaps the nose droops too.
If you raise the flaps the nose comes up. Same same for ailerons.
I've never done anything backwards, except reading a wind sock 180 degrees
out, entering traffic 180 degrees out, and I could go on.
Gosh, it would be nice to be perfect and not make all those mistakes. 
john h
mkIII
Titus, Alabama
Raising the aileron trailing edges (or flaps) moves the center of lift
forward, drooping the ailerons (or flaps) moves it aft.
My apologies to everyone, I'll fix it this afternoon.
(How come none of you guys caught that? You should have had my butt on a
plate a couple years ago for that one!)
--------
Richard Pike
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
_________________
John Hauck
MKIII/912ULS
hauck's holler
Titus, Alabama |
|
| Back to top |
|
|
neilsenrm(at)gmail.com
Guest
|
| Posted: Sun Aug 12, 2018 7:17 am Post subject: Kolb-List:Stabilizer Angle |
|
|
Bill
Wow never saw a Kolb horizontal stabilizer mounted so high. The photos show a bunch but brings up a lot of questions.
It hard to see from the angle of your photo but it looks like the horizontal stabilizer is in line with the wing. Is the wing set with a much higher angle of attack than stock? I can't comment on if that is good or bad. If it is higher, that would explain why the horizontal stabilizer has to be set that high. Be careful. What is the impact on all this?? Kolbs tend to look like they are flying a bit nose down but your plane might go a bit beyond that.
Rick Neilsen
Redrive VW Powered MKIIIC
On Sat, Aug 11, 2018 at 8:07 PM Bill Berle <victorbravo(at)sbcglobal.net (victorbravo(at)sbcglobal.net)> wrote:
| Quote: | Per the previous discussions regarding my FS2 / HKS testing, I have raised the leading edge of the stabilizers significantly higher than they had originally been, in order to counteract the amount of stick force I had to hold to keep the nose level.
I am trying to attach photos of the modification to this e-mail.
These photos represent the mounting point 1.25 inches above the original mounting.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities |
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
|
|
| Back to top |
|
|
victorbravo(at)sbcglobal.
Guest
|
| Posted: Sun Aug 12, 2018 8:29 am Post subject: Kolb-List:Stabilizer Angle |
|
|
I tried to take 0one of the photos showing that the angleo f the tail is nearly equal to the angle of the lower surface of the wing.
Since I did not build this aircraft originally, I have no idea if the wing angle is higher or lower than stock. It looks really high because I put taller landing gear (Kolb Slingshot) on it, plus big tires.
I will try at least one "crow hop" down the runway with the stabilizer set like it is in the photo. If it seems controllable then I will continue climbing and flying, If it requires a large pull rearward on the stick then I will land and re-set the stabilizer angle to the last setting which was safe enough to make the last test flight.
Regarding drooping the ailerons: Last time I flew I did NOT notice that the ailerons were flexed upward by air loads. They looked like they were parallel to the bottom wing surface. If the ailerons were flying in a reflexed upward position I would have seen the balance weights below the wing, which I did not.
I also moved the control stick left and right firmly, and I did not see the ailerons twisting (meaning more movement at the inboard end of the aileron than the outboard). So I have to say that form my limited amount of testing it does NOT seem that the ailerons are "springy", or that the air moves them upward. So it seems that drooping them on the ground would make them fly in the same drooped position. I can easily see how this will pitch the nose down and solve part or all of the trim problem, but I cannot understand how this will not create "wash-in" or aerodynamic twist in the wrong direction. Can someone explain to me WHY drooping the ailerons will NOT create a wiing that stalls at the tips before the root?
I am absolutely 1000% happy and willing to try drooping the ailerons, so long as I can understand why it will not make the aircraft more prone to tip stall.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
--------------------------------------------
On Sun, 8/12/18, Rick Neilsen <neilsenrm(at)gmail.com> wrote:
Bill
Wow never saw a Kolb horizontal stabilizer mounted so high. The photos show a bunch but brings up a lot of questions.
It hard to see from the angle of your photo but it looks like the horizontal stabilizer is in line with the wing. Is the wing set with a much higher angle of attack than stock? I can't comment on if that is good or bad. If it is higher, that would explain why the horizontal stabilizer has to be set that high. Be careful. What is the impact on all this?? Kolbs tend to look like they are flying a bit nose down but your plane might go a
bit beyond that.
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
|
|
| Back to top |
|
|
gdhelton(at)gmail.com
Guest
|
| Posted: Sun Aug 12, 2018 9:28 am Post subject: Kolb-List:Stabilizer Angle |
|
|
Bill, Kolbs do not have built in twist or “wash out” in the wings like your Cessna. They intentionally built flat. Your wing is not stalling at 50 mph. It’s a high lift/ high drag wing. The leading edge rib design is there to establish smooth directional air flow over the entire wing. This is also why the wing doesn’t require any dihedral to be added. If you want to add dihedral it simply adds more stability, which makes it more of rubbered plane then aileron controlled.
Take a long straight edge and put it along the bottom of the wing and make sure the aileron is centered and not in reflex. Make sure they equal at the trailing edge. Now, initially shorten your rod ends two full turns. I would return the angle of incidence of the horizontal stabilizer back to what was originally. Test fly the airplane. If the stick pressure has lighten a bit. You’re doing the right thing. You may have do this a couple of times. If anyone disagrees with this advice please chime in. It ‘s been many years since I set mine. It flies great with very little rudder input except for climbing with increased power settings and naturally during takeoff and landing. I have no trim tabs at all. But, I think that’s the exception. But, Homer Kolb thought it was the way to go if necessary. I had a adjustable elevator trim tab on my MKII which came as standard equipment.
George H.
Firestar, FS100, 2702 Hirth
14GDH
Mesick, Michigan
gdhelton(at)gmail.com
Sent from my iPhone
| Quote: | On Aug 12, 2018, at 12:29 PM, Bill Berle <victorbravo(at)sbcglobal.net> wrote:
I tried to take 0one of the photos showing that the angleo f the tail is nearly equal to the angle of the lower surface of the wing.
Since I did not build this aircraft originally, I have no idea if the wing angle is higher or lower than stock. It looks really high because I put taller landing gear (Kolb Slingshot) on it, plus big tires.
I will try at least one "crow hop" down the runway with the stabilizer set like it is in the photo. If it seems controllable then I will continue climbing and flying, If it requires a large pull rearward on the stick then I will land and re-set the stabilizer angle to the last setting which was safe enough to make the last test flight.
Regarding drooping the ailerons: Last time I flew I did NOT notice that the ailerons were flexed upward by air loads. They looked like they were parallel to the bottom wing surface. If the ailerons were flying in a reflexed upward position I would have seen the balance weights below the wing, which I did not.
I also moved the control stick left and right firmly, and I did not see the ailerons twisting (meaning more movement at the inboard end of the aileron than the outboard). So I have to say that form my limited amount of testing it does NOT seem that the ailerons are "springy", or that the air moves them upward. So it seems that drooping them on the ground would make them fly in the same drooped position. I can easily see how this will pitch the nose down and solve part or all of the trim problem, but I cannot understand how this will not create "wash-in" or aerodynamic twist in the wrong direction. Can someone explain to me WHY drooping the ailerons will NOT create a wiing that stalls at the tips before the root?
I am absolutely 1000% happy and willing to try drooping the ailerons, so long as I can understand why it will not make the aircraft more prone to tip stall.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
--------------------------------------------
On Sun, 8/12/18, Rick Neilsen <neilsenrm(at)gmail.com> wrote:
Bill
Wow never saw a Kolb horizontal stabilizer mounted so high. The photos show a bunch but brings up a lot of questions.
It hard to see from the angle of your photo but it looks like the horizontal stabilizer is in line with the wing. Is the wing set with a much higher angle of attack than stock? I can't comment on if that is good or bad. If it is higher, that would explain why the horizontal stabilizer has to be set that high. Be careful. What is the impact on all this?? Kolbs tend to look like they are flying a bit nose down but your plane might go a
bit beyond that.
|
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
|
|
| Back to top |
|
|
gdhelton(at)gmail.com
Guest
|
| Posted: Sun Aug 12, 2018 9:32 am Post subject: Kolb-List:Stabilizer Angle |
|
|
I still think you have c/g problem more anything else. Which I mentioned in a earlier email.
George H.
Firestar
Mesick, Michigan
Sent from my iPhone
| Quote: | On Aug 12, 2018, at 12:29 PM, Bill Berle <victorbravo(at)sbcglobal.net> wrote:
I tried to take 0one of the photos showing that the angleo f the tail is nearly equal to the angle of the lower surface of the wing.
Since I did not build this aircraft originally, I have no idea if the wing angle is higher or lower than stock. It looks really high because I put taller landing gear (Kolb Slingshot) on it, plus big tires.
I will try at least one "crow hop" down the runway with the stabilizer set like it is in the photo. If it seems controllable then I will continue climbing and flying, If it requires a large pull rearward on the stick then I will land and re-set the stabilizer angle to the last setting which was safe enough to make the last test flight.
Regarding drooping the ailerons: Last time I flew I did NOT notice that the ailerons were flexed upward by air loads. They looked like they were parallel to the bottom wing surface. If the ailerons were flying in a reflexed upward position I would have seen the balance weights below the wing, which I did not.
I also moved the control stick left and right firmly, and I did not see the ailerons twisting (meaning more movement at the inboard end of the aileron than the outboard). So I have to say that form my limited amount of testing it does NOT seem that the ailerons are "springy", or that the air moves them upward. So it seems that drooping them on the ground would make them fly in the same drooped position. I can easily see how this will pitch the nose down and solve part or all of the trim problem, but I cannot understand how this will not create "wash-in" or aerodynamic twist in the wrong direction. Can someone explain to me WHY drooping the ailerons will NOT create a wiing that stalls at the tips before the root?
I am absolutely 1000% happy and willing to try drooping the ailerons, so long as I can understand why it will not make the aircraft more prone to tip stall.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
--------------------------------------------
On Sun, 8/12/18, Rick Neilsen <neilsenrm(at)gmail.com> wrote:
Bill
Wow never saw a Kolb horizontal stabilizer mounted so high. The photos show a bunch but brings up a lot of questions.
It hard to see from the angle of your photo but it looks like the horizontal stabilizer is in line with the wing. Is the wing set with a much higher angle of attack than stock? I can't comment on if that is good or bad. If it is higher, that would explain why the horizontal stabilizer has to be set that high. Be careful. What is the impact on all this?? Kolbs tend to look like they are flying a bit nose down but your plane might go a
bit beyond that.
|
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
|
|
| Back to top |
|
|
wrk2win4u
Joined: 12 Nov 2011
Posts: 30
|
| Posted: Sun Aug 12, 2018 10:05 am Post subject: Kolb-List:Stabilizer Angle |
|
|
Hi Bill,
I was just looking at the photos. Are your fuel tanks mounted side by side or inline?
From: owner-kolb-list-server(at)matronics.com <owner-kolb-list-server(at)matronics.com> on behalf of Bill Berle <victorbravo(at)sbcglobal.net>
Sent: Saturday, August 11, 2018 6:04:11 PM
To: kolb-list(at)matronics.com
Subject: RE: Kolb-List:Stabilizer Angle
Per the previous discussions regarding my FS2 / HKS testing, I have raised the leading edge of the stabilizers significantly higher than they had originally been, in order to counteract the amount of stick force I had to hold to keep the nose level.
I am trying to attach photos of the modification to this e-mail.
These photos represent the mounting point 1.25 inches above the original mounting.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
|
|
| Back to top |
|
|
capedavis(at)yahoo.com
Guest
|
| Posted: Sun Aug 12, 2018 10:30 am Post subject: Kolb-List:Stabilizer Angle |
|
|
Have u flown it yet? Looks to a non engineer like a drastic change.
Sent from my iPhone
| Quote: | On Aug 11, 2018, at 8:04 PM, Bill Berle <victorbravo(at)sbcglobal.net> wrote:
Per the previous discussions regarding my FS2 / HKS testing, I have raised the leading edge of the stabilizers significantly higher than they had originally been, in order to counteract the amount of stick force I had to hold to keep the nose level.
I am trying to attach photos of the modification to this e-mail.
These photos represent the mounting point 1.25 inches above the original mounting.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
<Tail Extensions August 2018-1.JPG>
<Tail Extensions August 2018-2.JPG>
<Tail Extensions August 2018-3.JPG>
<Tail Extensions August 2018-4.JPG>
<Tail Extensions August 2018-5.JPG>
|
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
|
|
| Back to top |
|
|
stuart(at)harnerfarm.net
Guest
|
| Posted: Sun Aug 12, 2018 10:30 am Post subject: Kolb-List:Stabilizer Angle |
|
|
Bill,
The way I understand it drooping the ailerons will cause them to act as "flaps". This will slightly increase the lift of that portion of the wing while adding a small bit of drag to the bottom of the wing.
This small bit of drag will help move the nose in a downward position.
Going by Richard Pike's description it also moves the center of lift aft. Although in this case a small amount. One would think that this also would help move the nose downward.
A wing with a small amount of lift added by applying flaps will stall at a higher angle of attack, therefore the root with no flaps will stall before the tips with a little bit of flaps. This should mean that the tips will stall last while preserving aileron effectiveness up until the last bit of flow separates from the wing. Assuming the wings have no "twist" to them.
Somewhere in your plans there should be data about setting the fuselage to wing root angle. I would verify this on both wings. Then move on to verify that the wing tips have the same angle. Next I would seriously do the weight an balance again, myself just to confirm that it is correct. If you discover that your wings are anything but flat along the bottom it may be causing some of your problems. That is likely to cause a wing heavy problem but not a tail heavy problem unless they are twisted equally but that is another discussion entirely.
I would use different scales as a second check point. For this you don't have to have certified scales. For the W&B of my Firefly I bought three $25 bathroom scales from Walmart. I used known weights of various amounts and checked all 3 against the known value. To my surprise they all agreed within the 0.2# resolution of the scales. When I got the plane into level flight attitude, I put a scale under all wheels and took a reading. Then rotated the scales one wheel clockwise and took new readings. Then did it again. I averaged all the readings and calculated the CG. You could do the same kind of thing with scales that were not identical.
Doing an analysis of what is going on is a different process than second guessing the design. The first part of the analysis should be confirmation of the product against the design (plans). You already know that the plane flies tail heavy and that applying down elevator corrects this condition. A trim tab will also correct for this condition. Even though it may be a band-aid and not solve the underlying problem in the end it may be the most practical. By the same token adjusting the tail plane angle is also a band-aid if it was built to plans in the first place.
Sleuthing out the root cause could be fun and infuriating at the same time. Only you can decide how far you want to pursue it.
Along with double checking the W&B checking the boom tube length would seem most appropriate. I had not considered that someone might have intentionally cut it down from the plans. But you never know if you didn't do it yourself. 
If for some reason your CG is out of whack, no amount of tweaking or tabbing or twisting will solve that problem. It may mask the problem but it will still be there waiting to bite you in the butt at the worst time possible. Murphy and all that....
Best of luck and keep posting. We're here to help if we can.
Stuart
--
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
|
|
| Back to top |
|
|
victorbravo(at)sbcglobal.
Guest
|
| Posted: Sun Aug 12, 2018 11:01 am Post subject: Kolb-List:Stabilizer Angle |
|
|
Hi Kurt, thanks for chiming in on this discussion.
My fuel tanks are stock Kolb plastic cans in the stock (inline) position. I had briefly thought about putting the fuel where the rear "seat" was, but in the end I did not want to redesign that. I know other people have put the fuel in the "rear seat" location. It makes sense to me. If it turns out that my CG is behind the maximum Kolb factory limit then I may have to move the fuel, because there is not any safe place to put the battery in the front of the aircraft.
Stuart thank you for your input as well, and thanks to everyone else (John, Richard, George, Larry, and the "usual suspects") once again.
I am really sorry if I seem to have "an attitude" about any of this, but I absolutely promise I am not being a smart ass here. I just need the answers and opinions of others to make sense and not conflict with established basic aerodynamics or basic aircraft engineering principles.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
--------------------------------------------
On Sun, 8/12/18, K I <wrk2win4u(at)msn.com> wrote:
Subject: Re: Kolb-List:Stabilizer Angle
To: "kolb-list(at)matronics.com" <kolb-list(at)matronics.com>
Date: Sunday, August 12, 2018, 11:05 AM
Hi Bill,
I was just looking
at the photos. Are your fuel tanks mounted side by side or
inline?
From:
owner-kolb-list-server(at)matronics.com
<owner-kolb-list-server(at)matronics.com> on behalf of
Bill Berle <victorbravo(at)sbcglobal.net>
Sent: Saturday, August 11, 2018 6:04:11 PM
To: kolb-list(at)matronics.com
Subject: RE: Kolb-List:Stabilizer Angle
Per the
previous discussions regarding my FS2 / HKS testing, I have
raised the leading edge of the stabilizers significantly
higher than they had originally been, in order to counteract
the amount of stick force I had to hold to keep
the nose level.
I am trying to attach photos of the modification to this
e-mail.
These photos represent the mounting point 1.25 inches above
the original mounting.
Bill Berle
www.ezflaphandle.com
- safety & performance upgrade for light aircraft
www.grantstar.net
- winning proposals for non-profit and for-profit
entities
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
|
|
| Back to top |
|
|
ceengland7(at)gmail.com
Guest
|
| Posted: Sun Aug 12, 2018 12:12 pm Post subject: Kolb-List:Stabilizer Angle |
|
|
Here are a few thoughts from the guy with less Kolb time than you. (Probably less than 10 minutes. )
One possible reason to not get the same reversed inboard/outboard stall pattern when you droop the Kolb ailerons is that they are more or less full span, so the root gets the same change that a 'normal' plane's aileron area would get when the ailerons droop.
But I'm kinda in the cg camp, as well. Did you mention whether you had to pull the nose up to flair for landing, or did you have to push even in the flair? If you were always pushing, I wouldn't want to fly it again before *knowing* where the cg really is. I had one experience with a tail heavy Luscombe (water in the fuselage), and I'm quite proud to still be alive. I suspect that a Kolb, with the engine already behind the cg, could be completely unrecoverable if it has an out of limit aft cg
& the nose got 'up'.
As someone mentioned, I'd be verifying every measurement distance and angle you can find in the plans, before doing anything else. Then I'd re-do weight & balance, paying particular attention to not only where the datum is, but also where the measurement points are, because with the extended gear, everything changes. I have no idea how detailed the Firestar instructions are, but my prehistoric Twinstar plans had very little in the way of useful w&b instructions.
Charlie
On Sun, Aug 12, 2018 at 11:29 AM, Bill Berle <victorbravo(at)sbcglobal.net (victorbravo(at)sbcglobal.net)> wrote:
| Quote: | --> Kolb-List message posted by: Bill Berle <victorbravo(at)sbcglobal.net (victorbravo(at)sbcglobal.net)>
I tried to take 0one of the photos showing that the angleo f the tail is nearly equal to the angle of the lower surface of the wing.
Since I did not build this aircraft originally, I have no idea if the wing angle is higher or lower than stock. It looks really high because I put taller landing gear (Kolb Slingshot) on it, plus big tires.
I will try at least one "crow hop" down the runway with the stabilizer set like it is in the photo. If it seems controllable then I will continue climbing and flying, If it requires a large pull rearward on the stick then I will land and re-set the stabilizer angle to the last setting which was safe enough to make the last test flight.
Regarding drooping the ailerons: Last time I flew I did NOT notice that the ailerons were flexed upward by air loads. They looked like they were parallel to the bottom wing surface. If the ailerons were flying in a reflexed upward position I would have seen the balance weights below the wing, which I did not.
I also moved the control stick left and right firmly, and I did not see the ailerons twisting (meaning more movement at the inboard end of the aileron than the outboard). So I have to say that form my limited amount of testing it does NOT seem that the ailerons are "springy", or that the air moves them upward. So it seems that drooping them on the ground would make them fly in the same drooped position. I can easily see how this will pitch the nose down and solve part or all of the trim problem, but I cannot understand how this will not create "wash-in" or aerodynamic twist in the wrong direction. Can someone explain to me WHY drooping the ailerons will NOT create a wiing that stalls at the tips before the root?
I am absolutely 1000% happy and willing to try drooping the ailerons, so long as I can understand why it will not make the aircraft more prone to tip stall.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net - winning proposals for non-profit and for-profit entities
|
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
|
|
| Back to top |
|
|
victorbravo(at)sbcglobal.
Guest
|
| Posted: Sun Aug 12, 2018 11:50 pm Post subject: Kolb-List:Stabilizer Angle |
|
|
--------------------------------------------
On Sun, 8/12/18, Charlie England <ceengland7(at)gmail.com> wrote:
" But I'm kinda in the cg camp, as well. Did you mention whether you had to pull the nose up to flair for
landing, or did you have to push even in the flair? If you were always pushing, I wouldn't want to fly it again
before *knowing* where the cg really is."
My aircraft does NOT require a "push" during landing. I still pull the stick back to flare out and land.
I am absolutely certain that the CG on the day we did the W&B was within the factory specified limits. If I have been lucky enough to lose enough weight since then, so much that the aircraft is now outside of the Kolb specifications, well then that would answer a lot.
But it would not answer everything, because at an aft CG location your aircraft will stall SLOWER than it will at any other CG location. But it appears that my aircraft stalls a little faster than others.
I think the Kolb factory CG limit is something like 43% of MAC chord. Do you guys think that being anywhere within the factory CG is safe, or do you guys think that some of the Kolb factory CG numbers are unsafe?
| | - The Matronics Kolb-List Email Forum - | | | Use the List Feature Navigator to browse the many List utilities available such as the Email Subscriptions page, Archive Search & Download, 7-Day Browse, Chat, FAQ, Photoshare, and much more:
http://www.matronics.com/Navigator?Kolb-List |
|
|
|
| Back to top |
|
|
|
|
You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum
You cannot attach files in this forum
You can download files in this forum
|
Powered by phpBB © 2001, 2005 phpBB Group
|
Get Email Distribution Too!
FAQ
Search
Memberlist
Usergroups
Register
Profile
Log in to check your private messages
Log in
