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John Hauck
Joined: 09 Jan 2006
Posts: 4639
Location: Titus, Alabama (hauck's holler)
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 Posted: Mon Aug 13, 2018 5:52 pm Post subject: Kolb-List:Stabilizer Angle |
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I don't know.
What blows my mind is the adverse nose up pitch, but BB said he used aft stick to flare, which means the nose wanted to pitch down. Doesn't add up. I'm thinking the nose up pitch is not a bad as he thinks it is because he doesn't know what to expect and how simple it is to correct.
I'd certainly put all the control surfaces back where they belong. Make sure the aircraft is rigged correctly and go from there, one thing at a time.
BB probably hasn't acquired enough knowledge of the Kolb flight characteristics to know what to look for. It's going to take a bit of time in the cockpit to learn the aircraft. Not easy to fix an airplane if you don't know what it is supposed to be doing in the first place.
Not easy to try to help an individual fix his Kolb by email.
john h
mkIII
Titus, Alabama
From: owner-kolb-list-server(at)matronics.com [mailto:owner-kolb-list-server(at)matronics.com] On Behalf Of George Helton
Sent: Monday, August 13, 2018 8:10 PM
To: kolb-list(at)matronics.com
Subject: Re: Kolb-List:Stabilizer Angle
Yeah John, I think Bill should just go back to square one. Put everything back the way it was and take your original advice. Droop the ailerons and don’t try to figure out why. I think in the long run it will be aft c/g.
George H.
Firestar
Mesick, Michigan
Sent from my iPhone
On Aug 13, 2018, at 8:50 PM, John Hauck <jhauck(at)elmore.rr.com (jhauck(at)elmore.rr.com)> wrote:
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_________________
John Hauck
MKIII/912ULS
hauck's holler
Titus, Alabama |
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gdhelton(at)gmail.com
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| Posted: Mon Aug 13, 2018 6:05 pm Post subject: Kolb-List:Stabilizer Angle |
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I agreed, the transition to Kolbs can take a bit of time. Especially if you haven’t any experience ultralights before. Oh well, I think I’ll fly somewhere for breakfast in the morning and just enjoy flying the old Firestar.
George H.
Firestar
Mesick, Michigan
Sent from my iPhone
On Aug 13, 2018, at 9:52 PM, John Hauck <jhauck(at)elmore.rr.com (jhauck(at)elmore.rr.com)> wrote:
| Quote: | <![endif]--> <![endif]-->
I don't know.
What blows my mind is the adverse nose up pitch, but BB said he used aft stick to flare, which means the nose wanted to pitch down. Doesn't add up. I'm thinking the nose up pitch is not a bad as he thinks it is because he doesn't know what to expect and how simple it is to correct.
I'd certainly put all the control surfaces back where they belong. Make sure the aircraft is rigged correctly and go from there, one thing at a time.
BB probably hasn't acquired enough knowledge of the Kolb flight characteristics to know what to look for. It's going to take a bit of time in the cockpit to learn the aircraft. Not easy to fix an airplane if you don't know what it is supposed to be doing in the first place.
Not easy to try to help an individual fix his Kolb by email.
john h
mkIII
Titus, Alabama
From: owner-kolb-list-server(at)matronics.com (owner-kolb-list-server(at)matronics.com) [mailto:owner-kolb-list-server(at)matronics.com (owner-kolb-list-server(at)matronics.com)] On Behalf Of George Helton
Sent: Monday, August 13, 2018 8:10 PM
To: kolb-list(at)matronics.com (kolb-list(at)matronics.com)
Subject: Re: Kolb-List:Stabilizer Angle
Yeah John, I think Bill should just go back to square one. Put everything back the way it was and take your original advice. Droop the ailerons and don’t try to figure out why. I think in the long run it will be aft c/g.
George H.
Firestar
Mesick, Michigan
Sent from my iPhone
On Aug 13, 2018, at 8:50 PM, John Hauck <jhauck(at)elmore.rr.com (jhauck(at)elmore.rr.com)> wrote:
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victorbravo(at)sbcglobal.
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| Posted: Mon Aug 13, 2018 10:04 pm Post subject: Kolb-List:Stabilizer Angle |
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Let me clarify this "Adverse pitch" issue a little more, so I do not confuse or confound any of the nice people trying to help get to the bottom of this with me.
There is some amount of forward stick required to fly the airplane at 40-55 mph in level flight or descent. It is not "all the way forward" by any means. It is a few pounds of force, and a few inches of forward position.
I have not felt that I could let go of the stick at any time, on any flight thus far. It is absolutely clear that the aircraft would go nose up immediately. I relaxed the pressure once (without letting go of the grip) and it went nose up.
It did not go up "violently" like an aerobatic airshow maneuver. But at the low speeds I was flying, it would not take very long to reach stall speed, so I did not let go of it.
The aircraft HANDLED like it was a little tail heavy. It was not uncontrollable by any means, but it tail heaviness would have answered why it wanted to pitchupward if I let go.
However, when it came time to try a stall, it no longer behaved like it was tail heavy, it sta lled at a speed that APPEARED to be 5 mph faster than what I have read on the Kolb list for a VG equipped Kolb.
On landing the only thing I have done is to fly a nose down descending final approach with about half or 1/3 throttle. As I got close to the ground I would level out by either pulling the stick back or "allowing" the nose-up tendency to level the aircraft out. Based on what I have learned and read from all of you, I would wait until the last second or two, and execute the flare low to the ground, raising the nose by pulling back on the stick, to achieve a three point or "tail-low" landing.
Whether letting go of the stick would have made the aircraft flare on its own... I have no idea, because I did not want to risk the "Kolb Quit" or allowing the aircraft to get too slow at 3 or 4 feet AGL.
My purpose in telling the Kolb list that I pulled back on the stick to land was only to re-assure everybody that the aircraft was not so horribly tail-heavy that I needed to push the stick forward to prevent it from doing a vertical climb on landing. That was not the case. I did NOT need to push forward even in the landing flare. If that were the case I would have grounded the aircraft.
Now as for the aileron drooping issue, nothing would pelase me more than finding out that my ailerons were r3eflexe3d upward in flight,a nd bringing them down level with the wing would solve my problam. I would be overjoyed, because drooping the ailersons has a chance of lowering the stall speed a little.
I know that some of you are saying to droop the ailerons and don't ask why. That is not the mark of a cautions, safe pilot. A long-established basic principle of aerodynamics tells us that twisting the wingtip upwards as you get out towards the tip can potentially cause an unsafe condition. I am asking over and over again why this problem does not happen in a Kolb, because on this aircraft only the outer HALF of the wing ia aileron. So drooping the ailerons will definitely create a "Wash-out" reverse twist. If this aircraft had flaps, I would have already drooped both ailerons and flaps a few degrees, and my problem might have been solved.
So before I try that method, all I wanted was to be sure of how and why that basic law of aerodynmics might not apply to this aircraft even thought it applies to many other aircraft. I apologize again if my caution makes me seem like a spoiled child or a prima donna. Neither is the case (well I was a spoiled child but that was 40+ years ago).
So at this stage I am still waiting to meet with my engineer friend and re-visit the weight and balance numbers he had recorded. 90% of the Kolb List has bet on tail-heaviness as the problem here. Since I have lost a little weight between the weight and balance day and the test flight day, yes of course the aircraft might have been tail-heavy on the days I finally flew it. If the aircraft is beyond the Kolb CG range NOW at my current weight, then I will know that this is likely the cause, and I will have to eat crow on this list and move the fuel tanks forward (and re-set the tail back to where it was).
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net      - winning proposals for non-profit and for-profit entities
--------------------------------------------
On Mon, 8/13/18, John Hauck <jhauck(at)elmore.rr.com> wrote:
Subject: RE: Kolb-List:Stabilizer Angle
To: kolb-list(at)matronics.com
Date: Monday, August 13, 2018, 6:52 PM
#yiv2727135594
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#yiv2727135594 I don't know. Â What blows my mind is the adverse
nose up pitch, but BB said he used aft stick to flare, which
means the nose wanted to pitch down. Doesn't add up.Â
I'm thinking the nose up pitch is not a bad as he thinks
it is because he doesn't know what to expect and how
simple it is to correct. Â I'd certainly put all the
control surfaces back where they belong. Make sure the
aircraft is rigged correctly and go from there, one thing at
a time. Â BB probably hasn't acquired
enough knowledge of the Kolb flight characteristics to know
what to look for. It's going to take a bit of time in
the cockpit to learn the aircraft. Not easy to fix an
airplane if you don't know what it is supposed to be
doing in the first place. Â Not easy to try to help an
individual fix his Kolb by email.  john hmkIIITitus, Alabama    From:
owner-kolb-list-server(at)matronics.com
[mailto:owner-kolb-list-server(at)matronics.com] On Behalf
Of George Helton
Sent: Monday,
August 13, 2018 8:10 PM
To:
kolb-list(at)matronics.com
Subject: Re:
Kolb-List:Stabilizer Angle  Yeah John, I think Bill
should just go back to square one. Put everything back the
way it was and take your original advice. Droop the ailerons
and don’t try to figure out why. I think in the long run
it will be aft c/g. George H.Firestar Mesick, Michigan Sent from my
iPhone
On Aug 13,
2018, at 8:50 PM, John Hauck <jhauck(at)elmore.rr.com>
wrote:Don't have to worry about tail
boom anymore. john hmkIIITitus, Alabama From: owner-kolb-list-server(at)matronics.com
[mailto:owner-kolb-list-server(at)matronics.com]
On Behalf Of Larry Cottrell
Sent: Monday, August 13, 2018 7:44 PM
To: kolb-list(at)matronics.com
Subject: Re: Kolb-List:Stabilizer
Angle My Firestar II measures 10.6
inches as well. So his tube is not shortened.LarryÂ
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Ducati SS
Joined: 15 Oct 2009
Posts: 93
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| Posted: Tue Aug 14, 2018 4:45 am Post subject: Re: Kolb-List:Stabilizer Angle |
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Saw a 377 powered Firestar at the local airport with the same mod.My Firefly requires considerable forward stick for level flight though all other flight characteristics are wonderful. I did shorten the boom by 8".
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baberdk
Joined: 23 Jan 2014
Posts: 53
Location: East Moline, Il
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| Posted: Tue Aug 14, 2018 5:48 am Post subject: Kolb-List:Stabilizer Angle |
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Instead of adding weight for CoG we would calculate where the battery should be to be in the middle of CoG. It is usually easy to move the battery and doesn't add any weight. It also helped the trim problem.
Respectfully,
Dennis Baber
Cape Coral, Fl
baberdk(at)gmail.com (baberdk(at)gmail.com)
305-814-7218
Stay CuriousÂ
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baberdk
Joined: 23 Jan 2014
Posts: 53
Location: East Moline, Il
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| Posted: Tue Aug 14, 2018 5:49 am Post subject: Kolb-List:Stabilizer Angle |
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Yes, the opposite of lift is gravity but if you want to fly slow you increase the angle of attack. It will make you fly slower up to around 16 degrees.
Respectfully,
Dennis Baber
Cape Coral, Fl
baberdk(at)gmail.com (baberdk(at)gmail.com)
305-814-7218
Stay CuriousÂ
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Rex Rodebush
Joined: 10 Jan 2006
Posts: 209
Location: Branson West area, Missouri
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| Posted: Tue Aug 14, 2018 7:22 am Post subject: Re: Kolb-List:Stabilizer Angle |
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Bill,
Have been following this thread and will make a few comments. I have a Mark III Xtra so it may be a apple and oranges comparison. My Kolb has to be flown all the time. Even if I trim it up as best I can, if I let go of the stick after about 3 or 5 seconds it will go up, down, right or left and I have to lightly regain control. I don't think Kolbs are like 172's where you can trim them up and then read a book.
My air speed indicator was off about 15 mph on the first flight. With a lot of speed runs and modifications to the pitot and static locations was able to get it very true to actual airspeed. Your 5 mph "high stall speed" could very well be instrument error.
When I'm landing I use up and/or down stick as required to keep it in the 3 point attitude (same as when sitting on the ground) and bring it down to just above the runway. The Kolb will slow down, stall and land, almost automatically.
I'm now flying right at the aft CG "limit", maybe even a 1/4" past it or so. I don't think this is unusual from other comments in the past on the list. It flies fine. I use the flaps slightly down for trim solo and the the standard trim for nose up with a passenger. I weigh now about 155-160 lbs. When I was 35 lbs heaver I don't think I bothered with the down trim.
I don't know how stiff your wing is in torsion but I can't believe aileron loading would move my Xtra wing any significant distance. Put a digital level on your wing and try to twist it.
Just my general ramblings. Always worth what you paid for them.
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Jerry-TS-MkII
Joined: 23 Aug 2017
Posts: 79
Location: Indiana
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| Posted: Tue Aug 14, 2018 7:27 am Post subject: Re: Kolb-List:Stabilizer Angle |
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Just a few more comments...
I don't have Kolb flight experience.. but if I had a choice between a plane that required several lbs of forward stick to maintain level flight, versus tip wash out, I'd want to have a neutral stick (or close).
I've not seen your CG% numbers, but you said "they were within specs", but also mentioned a 43% reward range. (Which everyone else seems to agree is way too far aft). WHAT is your CG% of MAC (full chord)? Maybe I missed reading a post, but THAT should be something you can verify from your paperwork, or that you SHOULD know!!
Easiest mod? Adding some nose weight, just to see if that helps.
Drooping the ailerons? Also a easy adjustment. And consider this RE tip wash out: if you adjust the aileron trail downwards, they too act like trim tabs.. and they can (and will) slightly twist the wing by doing so, into a wash out angle. It might be hard to measure or observe, but down aileron will twist the wing (and reduce the angle of attack slightly). That could be the answer you seek, re washout. It could also be a partial resolution to stick force issues.
On a early post about this plane, you mentioned bent tubes, and "He ran into something". Your plane may not be "aligned" via the building fixture at Kolb, but instead tweaked by some "other input". (One aspect of buying used).
As for less forward pressure at landing. Your airspeed is much reduced, your power is much reduced, and you are in ground effect. The elevator is much less effective at the slower speeds, and you are "wanting" to basically stall the plane at touchdown. I find nothing surprising about needing aft stick at that point. It's not the primary concern RE your stick forces.
You may consider having your engineer friend evaluate the lift generated by the flat horizontal stab, at your starting point, and the exaggerated angle too (at various speeds). And then revise the stab airfoil, and re-run the numbers. A lifting stab keeps a plane flat(er) at high speeds. One possibility, if all else is unsatisfactory. Building a R/C model might be a good way to evaluate that possible mod.
You and I may be the only two on the Kolb list, who agree.. you SHOULD be able to let go of the control stick, and it flys straight and level. Mine will have a adjustable trim tab, which alone could fly the plane if needed. And not a bungee on the stick or a sore arm!! LOL
Jerry
TS MKII
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victorbravo(at)sbcglobal.
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| Posted: Tue Aug 14, 2018 10:33 am Post subject: Kolb-List:Stabilizer Angle |
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To answer a few more questions:
I had made up a 9 degree plywood wedge with a bubble level taped to it. This was held underneath the wing surface at several locations on both wings during the weight and balance process. My Firestar plans say clearly that the wing needs to be at 9 degrees for the weight and balance. It was.
The reason I had a real aero engineer there in the first place is because I am not completely proficient to do a proper weight and balance. I learned it many years ago at A&P mechanic school, but I have have never had to do it since then because I am not a working A&P mechanic.
I have no idea what the angle between the wing and the fuselage is. Part of this is because I don't know what part of the fuselage you are supposed to measure for that. If there is a specific place where that measurement is taken then I will take that measurement and report it to the group.
But there are no visible modifications to the upper fuselage cage, no weld repairs, no bent tubes, etc. It certainly does not look like it was rebuilt or changed in that area.
Kolbs have various different "angle of incidence" for the wings depending on which model and what the use for the airplane is. The Slingshot had a much lower incidence angle on the same basic wing because it was supposed to be a much faster aircraft. Kolb adjusted the angles of wing, fuselage, and tail in many many different variations. You can easily see this just by looking at the photos of the flying aircraft.
Because of the Kolb's unique wing folding hinge, the only thing they had to do to adjust the angle of incidence in most cases was to drill the bolt hole in the wing root fitting higher or lower. Then they adjusted the stabilizer angle to provide the proper amount of decalage angle between the wing and tail. This allowed Kolb to experiment and customize the same basic components into many different models over the years. Very clever and it worked well.
In my case I cannot (and should not) re-drill the hole in the root fitting. My aircraft had badly worn oval bolt holes in this fitting, and I repaired it by bolting reinforcement doublerplates to either side of the fitting. This gives me essentially a new hole in new metal, and I still have the old hole and old metal as a backup. Safe and strong. But I cannot simply drill a new hole because the reinforcements and fasteners are there.
There is very little torsional movement in the leading edge of the ailerons. I held the root end of the control arm and a friend of mine held the tip of the aileron, and we twisted it. It was pretty stiff, not "springy" at all. I also looked at the ailerons in flight, and when I moved them the inboard and outboard ends of the ailerons were both at the same angle... littleor no twisting of the aileron itself in flight.
I am going to get the original weight and balance calculations this week, and I wil post exactly what we found. Then I will have a calculation done on where the CG is with my current body weight,a and see if my weight loss has thrown the aircraft out of the Kolb approved range.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net      - winning proposals for non-profit and for-profit entities
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Rex Rodebush
Joined: 10 Jan 2006
Posts: 209
Location: Branson West area, Missouri
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| Posted: Tue Aug 14, 2018 4:42 pm Post subject: Re: Kolb-List:Stabilizer Angle |
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When I set up my wing I called Brian at TNK. He gave me the recommended wing and horizontal stabilizer angles in reference to the motor mounts. ie, get a digital level, set it on the motor mounts and zero it, then check both wings at several points and average the results. Same for the stabilizer. I would call Brian and get the angles for your model.
Where you have your stabilizer now is so far from everyone else that something is definitely wrong.
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victorbravo(at)sbcglobal.
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| Posted: Wed Aug 15, 2018 7:21 am Post subject: Kolb-List:Stabilizer Angle |
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Just landed after test flight #4. Aircraft is safe and controllable with stabilizer mount bolt 1.125" above original location. Still needs light forward stick. But not as much as before. NOW it is within the range of a simple trim tab. Ailerons are level with wing undersurface in flight, not trailing upward. Installed higher quality pitot/static probe and hooked static to airspeed indicator. Stall speed now down where it was expected, 30 mph. But level flight speed is still in the 40-45 mph range at 5300-5500 rpm. Putting on the windshield may solve part of this, but I still believe there is some other cause of the slow speed. I am willing to do any and all drag reduction, that is the fun part for an old sailplane racer. I also installed two rudder trim tabs which reduced the need for left rudder. That will now be manageable. So at least this is all moving in the right direction.
Sent from my Samsung Captivate(tm) on AT&T
Rex Rodebush <jrrodebush(at)gmail.com> wrote:
| Quote: |
When I set up my wing I called Brian at TNK. He gave me the recommended wing and horizontal stabilizer angles in reference to the motor mounts. ie, get a digital level, set it on the motor mounts and zero it, then check both wings at several points and average the results. Same for the stabilizer. I would call Brian and get the angles for your model.
Where you have your stabilizer now is so far from everyone else that something is definitely wrong.
Read this topic online here:
http://forums.matronics.com/viewtopic.php?p=482402#482402
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victorbravo(at)sbcglobal.
Guest
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| Posted: Wed Aug 15, 2018 9:43 am Post subject: Kolb-List:Stabilizer Angle |
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I cannot find any reference in the 1993 plans that gives me the wing incidence angle. It shows "level" at 9 degrees for W&B but nothing about the angle between wing and fuselage.
Sent from my Samsung Captivate(tm) on AT&T
Bill <victorbravo(at)sbcglobal.net> wrote:
| Quote: |
Just landed after test flight #4. Aircraft is safe and controllable with stabilizer mount bolt 1.125" above original location. Still needs light forward stick. But not as much as before. NOW it is within the range of a simple trim tab. Ailerons are level with wing undersurface in flight, not trailing upward. Installed higher quality pitot/static probe and hooked static to airspeed indicator. Stall speed now down where it was expected, 30 mph. But level flight speed is still in the 40-45 mph range at 5300-5500 rpm. Putting on the windshield may solve part of this, but I still believe there is some other cause of the slow speed. I am willing to do any and all drag reduction, that is the fun part for an old sailplane racer. I also installed two rudder trim tabs which reduced the need for left rudder. That will now be manageable. So at least this is all moving in the right direction.
Sent from my Samsung Captivate(tm) on AT&T
Rex Rodebush <jrrodebush(at)gmail.com> wrote:
>
>
>When I set up my wing I called Brian at TNK. He gave me the recommended wing and horizontal stabilizer angles in reference to the motor mounts. ie, get a digital level, set it on the motor mounts and zero it, then check both wings at several points and average the results. Same for the stabilizer. I would call Brian and get the angles for your model.
>
>Where you have your stabilizer now is so far from everyone else that something is definitely wrong.
>
>
>Read this topic online here:
>
>http://forums.matronics.com/viewtopic.php?p=482402#482402
>
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gdhelton(at)gmail.com
Guest
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| Posted: Wed Aug 15, 2018 10:08 am Post subject: Kolb-List:Stabilizer Angle |
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|
I think you’re doing fine Bill. As for speed? I wouldn’t worry a lot about it right now. Your speed actually sounds pretty good. Learn to fly her at 45 or 50 that’s good ultralighting speed. Work on your landings alittle. I’m sure if you crank up the rpm it’ll do 55 or 65. You might have to push forward on the stick alittle more but, she’ll go faster. My little old Firestar loves cruising around at 52 to 55 mph. Go have some fun!
George H.
Firestar, FS100, 2702 Hirth
14GDH
Mesick, Michigan
gdhelton(at)gmail.com
Sent from my iPhone
| Quote: | On Aug 15, 2018, at 1:42 PM, Bill <victorbravo(at)sbcglobal.net> wrote:
I cannot find any reference in the 1993 plans that gives me the wing incidence angle. It shows "level" at 9 degrees for W&B but nothing about the angle between wing and fuselage.
Sent from my Samsung Captivate(tm) on AT&T
Bill <victorbravo(at)sbcglobal.net> wrote:
>
>
> Just landed after test flight #4. Aircraft is safe and controllable with stabilizer mount bolt 1.125" above original location. Still needs light forward stick. But not as much as before. NOW it is within the range of a simple trim tab. Ailerons are level with wing undersurface in flight, not trailing upward. Installed higher quality pitot/static probe and hooked static to airspeed indicator. Stall speed now down where it was expected, 30 mph. But level flight speed is still in the 40-45 mph range at 5300-5500 rpm. Putting on the windshield may solve part of this, but I still believe there is some other cause of the slow speed. I am willing to do any and all drag reduction, that is the fun part for an old sailplane racer. I also installed two rudder trim tabs which reduced the need for left rudder. That will now be manageable. So at least this is all moving in the right direction.
>
> Sent from my Samsung Captivate(tm) on AT&T
>
> Rex Rodebush <jrrodebush(at)gmail.com> wrote:
>
>>
>>
>> When I set up my wing I called Brian at TNK. He gave me the recommended wing and horizontal stabilizer angles in reference to the motor mounts. ie, get a digital level, set it on the motor mounts and zero it, then check both wings at several points and average the results. Same for the stabilizer. I would call Brian and get the angles for your model.
>>
>> Where you have your stabilizer now is so far from everyone else that something is definitely wrong.
>>
>>
>>
>>
>> Read this topic online here:
>>
>> http://forums.matronics.com/viewtopic.php?p=482402#482402
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
>
>
|
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victorbravo(at)sbcglobal.
Guest
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| Posted: Wed Aug 15, 2018 10:57 am Post subject: Kolb-List:Stabilizer Angle |
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Just spent 45 minutes on the phone with Duane at Kolb. Great guy! He also thinks the stabilizer should not be that high. He will show the pictures to Bryan.
Sent from my Samsung Captivate(tm) on AT&T
Bill <victorbravo(at)sbcglobal.net> wrote:
| Quote: |
I cannot find any reference in the 1993 plans that gives me the wing incidence angle. It shows "level" at 9 degrees for W&B but nothing about the angle between wing and fuselage.
Sent from my Samsung Captivate(tm) on AT&T
Bill <victorbravo(at)sbcglobal.net> wrote:
>
>
>Just landed after test flight #4. Aircraft is safe and controllable with stabilizer mount bolt 1.125" above original location. Still needs light forward stick. But not as much as before. NOW it is within the range of a simple trim tab. Ailerons are level with wing undersurface in flight, not trailing upward. Installed higher quality pitot/static probe and hooked static to airspeed indicator. Stall speed now down where it was expected, 30 mph. But level flight speed is still in the 40-45 mph range at 5300-5500 rpm. Putting on the windshield may solve part of this, but I still believe there is some other cause of the slow speed. I am willing to do any and all drag reduction, that is the fun part for an old sailplane racer. I also installed two rudder trim tabs which reduced the need for left rudder. That will now be manageable. So at least this is all moving in the right direction.
>
>Sent from my Samsung Captivate(tm) on AT&T
>
>Rex Rodebush <jrrodebush(at)gmail.com> wrote:
>
>>
>>
>>When I set up my wing I called Brian at TNK. He gave me the recommended wing and horizontal stabilizer angles in reference to the motor mounts. ie, get a digital level, set it on the motor mounts and zero it, then check both wings at several points and average the results. Same for the stabilizer. I would call Brian and get the angles for your model.
>>
>>Where you have your stabilizer now is so far from everyone else that something is definitely wrong.
>>
>>
>>
>>
>>Read this topic online here:
>>
>>http://forums.matronics.com/viewtopic.php?p=482402#482402
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
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victorbravo(at)sbcglobal.
Guest
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| Posted: Wed Aug 15, 2018 7:52 pm Post subject: Kolb-List:Stabilizer Angle |
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Back from the airport. This morning I got in a 30-35 minute test flight which included four or five landings.
The stabilizer was raised to 1.125" above the original bolt hole for this flight. As I mentioned earlier, the aircraft flew acceptably well, the stick force was less than before. However, I understand my stabilizer is higher than almost any other Kolb. This has everyone up in arms, including Duane at Kolb, and including me, since I want to know what it so strange about the aircraft I am flying.
As mentioned, I spent 45 minutes on the phone with Duane today at Kolb. He gave me the exact measurements that the wing and tail incidence is supposed to be on a Firestar 2. The WING incidence is set bu where you drill the hole in the main spar pin attachment at the steel fitting that rivets to the spar tube. The measurement is supposed to be 3 inches form the bottom surface up to the center of the hole. My aircraft is 3 and 1/16 inches HIGHER than the lower surface. This means that my wing will be 1/16 of an inch LOWER when the pin goes through the hole in the fuselage carry-through... which means my wing incidence is LOWER than a perfect plans built Firestar.
By all logic this means that I should be pulling back on the stick a little, not pushing forward.
The stock plans-built Firestar has the stabilizer bolt 3/8 of an inch above the top of the fuselage boom tube., Mine is a LOT higher than that as we can all see from the photos posted previously.
So we have an aircraft that:
1) Has the main wing incidence very close to a perfect plans-built specification, and it is even 1/16 inch lower.
2) We have an aircraft that balanced at 32% of wing chord, and is allowed to go up to 37% of chord.
3) We have an aircraft that has the full-length, un-cut tailboom tube.
4) We have an aircraft that has no warps, twists, or bends in the wings (they are flat on the bottom, root to tip).
5) We have an aircraft that does NOT have the ailerons reflexed upward in flight with air loads on them.
And yet the aircraft still has some amount of nose-up pitch with the stabilizer at 3/8 inch, 3/4 inch, AND 1.125 inch above the tailboom tube. I DO NOT want to raise it any higher, because the Kolb List and the Kolb Aircraft Company and a bunch of experienced Kolbers are already thinking it is way too high. It looks pretty darn high to me too.
So today I put two small aluminum trim tabs on the elevator to "fine tune" the last little bit of trim so I can let go of the stick for two seconds. I did this because so far all the guesses and possibilities about the stabilizer angle and wing incidence and aileron position are apparently NOT the cause of this. Which means if we weigh& balance it agaain and it is NOT outside of the Kolb approved range... then you and me and everyone else is just about out of ideas. Unless Bryan Melborn knows something the rest of the Kolbers don't know, then everyone is out of ideas.
I had also installed two small rudder trim tabs, which are 3/4 of the way to "fixing" the yaw trim.
Today's test flight included some final approaches with little or no power. I paid attention to the rudder during these approaches,a nd sure enough the amount of left rudder needed is a lot less with little or no power. So my aircraft is not significantly "bent" or warped in the yaw directiton, the rudder trim issue is directly related to the engine and prop wash just like everyone suspected. So a rudder triim tab is an easy and obvious fix. Maybe someday in the future I will put the engine on at a different angle, but that will be after I have fun flying it for a while.
Today's test flight also was equipped with a higher quality pitot and static probe, and it verified that the aircraft is making a lot more drag than it could be. 45 miles an hour cruise speed (downwind in the pattern) at 5600-5700 RPM. But I have not done any drag reduction on this aircraft yet, no fairings, no streamline struts, no tape over the control gaps, etc. etc. So I am guessing that I can find another 10-15 mph as I fiddle with the drag stuff.
I was supposed to meet with the guy who did the weight and balance today but he had to postpone it till Friday. The only thing that would explain all of this aircraft's strange behavior is if it is REALLY tail-heavy, and I do not believe it is outside of the Kolb CG range.
Anyway, again I REALLY appreciate everyone's interest and participation in trying to solve this puzzle. If any of the mroe highly experienced Kolb pilots want to come fly this aircraft themselves and try to figure it out, let me know.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net      - winning proposals for non-profit and for-profit entities
--------------------------------------------
On Wed, 8/15/18, Bill <victorbravo(at)sbcglobal.net> wrote:
Subject: Re: Kolb-List:Stabilizer Angle
To: kolb-list(at)matronics.com
Date: Wednesday, August 15, 2018, 11:56 AM
<victorbravo(at)sbcglobal.net>
Just spent 45 minutes on the phone with
Duane at Kolb. Great guy! He also thinks the stabilizer
should not be that high. He will show the pictures to Bryan.
Sent from my Samsung Captivate(tm) on
AT&T
Bill <victorbravo(at)sbcglobal.net>
wrote:
>
Bill <victorbravo(at)sbcglobal.net>
>
>I cannot find any reference in the
1993 plans that gives me the wing incidence angle. It shows
"level" at 9 degrees for W&B but nothing about the angle
between wing and fuselage.
>
>Sent from my Samsung Captivate(tm)
on AT&T
>
>Bill <victorbravo(at)sbcglobal.net>
wrote:
>
>>--> Kolb-List message posted
by: Bill <victorbravo(at)sbcglobal.net>
>>
>>Just landed after test flight
#4. Aircraft is safe and controllable with stabilizer mount
bolt 1.125" above original location. Still needs light
forward stick. But not as much as before. NOW it is within
the range of a simple trim tab. Ailerons are level with wing
undersurface in flight, not trailing upward. Installed
higher quality pitot/static probe and hooked static to
airspeed indicator. Stall speed now down where it was
expected, 30 mph. But level flight speed is still in the
40-45 mph range at 5300-5500 rpm. Putting on the windshield
may solve part of this, but I still believe there is some
other cause of the slow speed. I am willing to do any and
all drag reduction, that is the fun part for an old
sailplane racer. I also installed two rudder trim tabs which
reduced the need for left rudder. That will now be
manageable. So at least this is all moving in the right
direction.
>>
>>Sent from my Samsung
Captivate(tm) on AT&T
>>
>>Rex Rodebush <jrrodebush(at)gmail.com>
wrote:
>>
>>>--> Kolb-List message
posted by: "Rex Rodebush" <jrrodebush(at)gmail.com>
>>>
>>>When I set up my wing I
called Brian at TNK. He gave me the recommended wing
and horizontal stabilizer angles in reference to the motor
mounts. ie, get a digital level, set it on the motor
mounts and zero it, then check both wings at several points
and average the results. Same for the
stabilizer. I would call Brian and get the angles for
your model.Â
>>>
>>>Where you have your
stabilizer now is so far from everyone else that something
is definitely wrong.
>>>
>>>
>>>
>>>
>>>Read this topic online
here:
>>>
>>>http://forums.matronics.com/viewtopic.php?p=482402#482402
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>
>>
>>
>>
>
>
>
>
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ceengland7(at)gmail.com
Guest
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| Posted: Thu Aug 16, 2018 3:50 am Post subject: Kolb-List:Stabilizer Angle |
|
|
Hi Bill,
I'm afraid we're all just spitballing now, hoping something will stick to the wall. Having said that...
I think you mentioned flying without the windshield. Have you considered installing it for a test flight? I have no idea whether it generates any downforce on the nose; did you ask Kolb?
Is thrust angle the same as the rotax? Same height?
At what speed does it fly hands-off? If you need to push in cruise and pull to flair, there should be some speed in between requiring neutral pressure.
For a w&b 'sanity check', what does your engine weigh, compared to the expected Rotax, is it in the same location, and what does that muffler weigh? It obviously is pretty far aft of standard. Did y'all adjust your measurements for the extended gear legs?
Again, just spitballing; maybe it will push you into thinking of something none of us has considered.
Charlie
On Aug 15, 2018, at 11:54 PM, Bill Berle <victorbravo(at)sbcglobal.net (victorbravo(at)sbcglobal.net)> wrote: | Quote: | | Quote: | --> Kolb-List message posted by: Bill Berle <victorbravo(at)sbcglobal.net>Back from the airport. This morning I got in a 30-35 minute test flight which included four or five landings.The stabilizer was raised to 1.125" above the original bolt hole for this flight. As I mentioned earlier, the aircraft flew acceptably well, the stick force was less than before. However, I understand my stabilizer is higher than almost any other Kolb. This has everyone up in arms, including Duane at Kolb, and including me, since I want to know what it so strange about the aircraft I am flying.As mentioned, I spent 45 minutes on the phone with Duane today at Kolb. He gave me the exact measurements that the wing and tail incidence is supposed to be on a Firestar 2. The WING incidence is set bu where you drill the hole in the main spar pin attachment at the steel fitting that rivets to the spar tube. The measurement is supposed to be 3 inches form the bottom surface up to the center of the hole. My aircraft is 3 and 1/16 inches HIGHER than the lower surface. This means that my wing will be 1/16 of an inch LOWER when the pin goes through the hole in the fuselage carry-through... which means my wing incidence is LOWER than a perfect plans built Firestar. By all logic this means that I should be pulling back on the stick a little, not pushing forward.The stock plans-built Firestar has the stabilizer bolt 3/8 of an inch above the top of the fuselage boom tube., Mine is a LOT higher than that as we can all see from the photos posted previously.So we have an aircraft that:1) Has the main wing incidence very close to a perfect plans-built specification, and it is even 1/16 inch lower. 2) We have an aircraft that balanced at 32% of wing chord, and is allowed to go up to 37% of chord. 3) We have an aircraft that has the full-length, un-cut tailboom tube. 4) We have an aircraft that has no warps, twists, or bends in the wings (they are flat on the bottom, root to tip). 5) We have an aircraft that does NOT have the ailerons reflexed upward in flight with air loads on them.And yet the aircraft still has some amount of nose-up pitch with the stabilizer at 3/8 inch, 3/4 inch, AND 1.125 inch above the tailboom tube. I DO NOT want to raise it any higher, because the Kolb List and the Kolb Aircraft Company and a bunch of experienced Kolbers are already thinking it is way too high. It looks pretty darn high to me too.So today I put two small aluminum trim tabs on the elevator to "fine tune" the last little bit of trim so I can let go of the stick for two seconds. I did this because so far all the guesses and possibilities about the stabilizer angle and wing incidence and aileron position are apparently NOT the cause of this. Which means if we weigh& balance it agaain and it is NOT outside of the Kolb approved range... then you and me and everyone else is just about out of ideas. Unless Bryan Melborn knows something the rest of the Kolbers don't know, then everyone is out of ideas.I had also installed two small rudder trim tabs, which are 3/4 of the way to "fixing" the yaw trim. Today's test flight included some final approaches with little or no power. I paid attention to the rudder during these approaches,a nd sure enough the amount of left rudder needed is a lot less with little or no power. So my aircraft is not significantly "bent" or warped in the yaw directiton, the rudder trim issue is directly related to the engine and prop wash just like everyone suspected. So a rudder triim tab is an easy and obvious fix. Maybe someday in the future I will put the engine on at a different angle, but that will be after I have fun flying it for a while.Today's test flight also was equipped with a higher quality pitot and static probe, and it verified that the aircraft is making a lot more drag than it could be. 45 miles an hour cruise speed (downwind in the pattern) at 5600-5700 RPM. But I have not done any drag reduction on this aircraft yet, no fairings, no streamline struts, no tape over the control gaps, etc. etc. So I am guessing that I can find another 10-15 mph as I fiddle with the drag stuff. I was supposed to meet with the guy who did the weight and balance today but he had to postpone it till Friday. The only thing that would explain all of this aircraft's strange behavior is if it is REALLY tail-heavy, and I do not believe it is outside of the Kolb CG range.Anyway, again I REALLY appreciate everyone's interest and participation in trying to solve this puzzle. If any of the mroe highly experienced Kolb pilots want to come fly this aircraft themselves and try to figure it out, let me know.Bill Berlewww.ezflaphandle.com - safety & performance upgrade for light aircraftwww.grantstar.net - winning proposals for non-profit and for-profit entitiesOn Wed, 8/15/18, Bill <victorbravo(at)sbcglobal.net> wrote: Subject: Re: Kolb-List:Stabilizer Angle To: kolb-list(at)matronics.com Date: Wednesday, August 15, 2018, 11:56 AM --> Kolb-List message posted by: Bill <victorbravo(at)sbcglobal.net> Just spent 45 minutes on the phone with Duane at Kolb. Great guy! He also thinks the stabilizer should not be that high. He will show the pictures to Bryan. Sent from my Samsung Captivate(tm) on AT&T Bill <victorbravo(at)sbcglobal.net> wrote: | Quote: | | --> Kolb-List message posted by: |
Bill <victorbravo(at)sbcglobal.net> | Quote: | | I cannot find any reference in the |
1993 plans that gives me the wing incidence angle. It shows "level" at 9 degrees for W&B but nothing about the angle between wing and fuselage. | Quote: | | Sent from my Samsung Captivate(tm) |
on AT&T | Quote: | | Bill <victorbravo(at)sbcglobal.net> |
wrote: | Quote: | | Quote: | | --> Kolb-List message posted |
|
by: Bill <victorbravo(at)sbcglobal.net> | Quote: | | Quote: | | Just landed after test flight |
|
#4. Aircraft is safe and controllable with stabilizer mount bolt 1.125" above original location. Still needs light forward stick. But not as much as before. NOW it is within the range of a simple trim tab. Ailerons are level with wing undersurface in flight, not trailing upward. Installed higher quality pitot/static probe and hooked static to airspeed indicator. Stall speed now down where it was expected, 30 mph. But level flight speed is still in the 40-45 mph range at 5300-5500 rpm. Putting on the windshield may solve part of this, but I still believe there is some other cause of the slow speed. I am willing to do any and all drag reduction, that is the fun part for an old sailplane racer. I also installed two rudder trim tabs which reduced the need for left rudder. That will now be manageable. So at least this is all moving in the right direction. | Quote: | | Quote: | | Sent from my Samsung |
|
Captivate(tm) on AT&T | Quote: | | Quote: | | Rex Rodebush <jrrodebush(at)gmail.com> |
|
wrote: | Quote: | | Quote: | | Quote: | | --> Kolb-List message |
|
|
posted by: "Rex Rodebush" <jrrodebush(at)gmail.com> | Quote: | | Quote: | | Quote: | | When I set up my wing I |
|
|
called Brian at TNK. He gave me the recommended wing and horizontal stabilizer angles in reference to the motor mounts. ie, get a digital level, set it on the motor mounts and zero it, then check both wings at several points and average the results. Same for the stabilizer. I would call Brian and get the angles for your model. | Quote: | | Quote: | | Quote: | | Where you have your |
|
|
stabilizer now is so far from everyone else that something is definitely wrong. | Quote: | | Quote: | | Quote: | | Read this topic online |
|
|
here: The Kolb-List Email Forum - Navigator to browse List Un/Subscription, 7-Day Browse, Chat, FAQ, - MATRONICS WEB FORUMS - via the Web Forums! - NEW MATRONICS LIST WIKI - Email List Wiki! - List Contribution Web Site - support! href="http://www.matronics.com/Navigator?Kolb-List">http://www.matr> http://www.matronics.com/contribution |
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racerjerry
Joined: 15 Dec 2009
Posts: 202
Location: Deer Park, NY
|
| Posted: Thu Aug 16, 2018 4:06 am Post subject: Re: Kolb-List:Stabilizer Angle |
|
|
Bill, Did you redo your weight & balance?
I wish you would post the figures here so we could verify.
Kolb states the average wing chord is 64 inches (p74) for Firestar II.
I found a simplified method that reduces calculation error potential when doing W&B on the Kolb: Use the MAIN WHEEL centerline as your datum point. In this manner, Only the tail weight moment arm needs to be computed.
"H" (in inches) is then calculated by: Total Moments (tail only) / Total Weight).
Afterwards, the distance from Main Wheel Centerline to Wing Leading Edge is added back in.
Then % CG is found by (H x 100) / 64
My CG was 33.04 % with shortened tail boom. Your engine is a helluva' lot heavier than my 447.
I hope this helps.
Jerry King
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John Hauck
Joined: 09 Jan 2006
Posts: 4639
Location: Titus, Alabama (hauck's holler)
|
| Posted: Thu Aug 16, 2018 4:46 am Post subject: Kolb-List:Stabilizer Angle |
|
|
I've flown Larry Cottrell's FS2 many times. Larry's FS2 is powered with an HKS. Flies pretty damn good and cruises well over 65 mph. Wish I had paid more attention to the gauges. Well...I didn't fly it wide open anyhow. It has no adverse habits, big tires, etc. By all means, Bill B's FS2 should fly the same way if he built it to plans.
If Bill B's FS2 is set up according to plans, it would fly the same way with or without windshield. However, if he is flying the FS2 without a gap seal, that alone will kill airspeed and make the aircraft fly like a turd. It will perform awful and handle awful. That may be his problem. I really have no idea unless I had hands on to determine what's going on.
Kolbs are what they are, draggy. Not a whole lot one can do to get them streamlined and decrease some of that drag. Streamlined drag struts and gear legs will help a tiny, tiny bit. Not much one can do about dragging that big tail boom through the air sideways. That is what it is doing because it flies tail high. One of the reasons the Kolbra and SS are a little cleaner and fly faster is less incidence, tail boom flying straighter through the airstream, not at an angle.
Bill B's got a problem that is out of the norm. Changing the attitude of the engine won't help. I went through that exercise 30 years ago with my FS. It didn't help. I have experimented and tested every way I can to get a little more cruise speed out of my Kolbs. My FS and US both flew 75+ mph. My MKIII flies 95 mph. Only thing I've done to streamline the MKIII is streamlined lift struts. It is a heavy airplane. Why do my airplanes fly faster than others? I do not know for sure, but have a good idea it is how tight I shrink my fabric on all surfaces. I like it tight and I make it tight.
Bill B needs to make sure he pulls the anchor in before he takes off. 
john h
mkIII
Titus, Alabama
From: owner-kolb-list-server(at)matronics.com [mailto:owner-kolb-list-server(at)matronics.com] On Behalf Of Charlie England
Sent: Thursday, August 16, 2018 6:50 AM
To: kolb-list(at)matronics.com
Subject: Re: Kolb-List:Stabilizer Angle
Hi Bill,
I'm afraid we're all just spitballing now, hoping something will stick to the wall. Having said that...
I think you mentioned flying without the windshield. Have you considered installing it for a test flight? I have no idea whether it generates any downforce on the nose; did you ask Kolb?
Is thrust angle the same as the rotax? Same height?
At what speed does it fly hands-off? If you need to push in cruise and pull to flair, there should be some speed in between requiring neutral pressure.
For a w&b 'sanity check', what does your engine weigh, compared to the expected Rotax, is it in the same location, and what does that muffler weigh? It obviously is pretty far aft of standard. Did y'all adjust your measurements for the extended gear legs?
Again, just spitballing; maybe it will push you into thinking of something none of us has considered.
Charlie
On Aug 15, 2018, at 11:54 PM, Bill Berle <victorbravo(at)sbcglobal.net (victorbravo(at)sbcglobal.net)> wrote: | Quote: | | --> Kolb-List message posted by: Bill Berle <victorbravo(at)sbcglobal.net>Back from the airport. This morning I got in a 30-35 minute test flight which included four or five landings.The stabilizer was raised to 1.125" above the original bolt hole for this flight. As I mentioned earlier, the aircraft flew acceptably well, the stick force was less than before. However, I understand my stabilizer is higher than almost any other Kolb. This has everyone up in arms, including Duane at Kolb, and including me, since I want to know what it so strange about the aircraft I am flying.As mentioned, I spent 45 minutes on the phone with Duane today at Kolb. He gave me the exact measurements that the wing and tail incidence is supposed to be on a Firestar 2. The WING incidence is set bu where you drill the hole in the main spar pin attachment at the steel fitting that rivets to the spar tube. The measurement is supposed to be 3 inches form the bottom surface up to the center of the hole. My aircraft is 3 and 1/16Â inches HIGHER than the lower surface. This means that my wing will be 1/16 of an inch LOWER when the pin goes through the hole in the fuselage carry-through... which means my wing incidence is LOWER than a perfect plans built Firestar. By all logic this means that I should be pulling back on the stick a little, not pushing forward.The stock plans-built Firestar has the stabilizer bolt 3/8 of an inch above the top of the fuselage boom tube., Mine is a LOT higher than that as we can all see from the photos posted previously.So we have an aircraft that:1) Has the main wing incidence very close to a perfect plans-built specification, and it is even 1/16 inch lower. 2) We have an aircraft that balanced at 32% of wing chord, and is allowed to go up to 37% of chord. 3) We have an aircraft that has the full-length, un-cut tailboom tube. 4) We have an aircraft that has no warps, twists, or bends in the wings (they are flat on the bottom, root to tip). 5) We have an aircraft that does NOT have the ailerons reflexed upward in flight with air loads on them.And yet the aircraft still has some amount of nose-up pitch with the stabilizer at 3/8 inch, 3/4 inch, AND 1.125 inch above the tailboom tube. I DO NOT want to raise it any higher, because the Kolb List and the Kolb Aircraft Company and a bunch of experienced Kolbers are already thinking it is way too high. It looks pretty darn high to me too.So today I put two small aluminum trim tabs on the elevator to "fine tune" the last little bit of trim so I can let go of the stick for two seconds. I did this because so far all the guesses and possibilities about the stabilizer angle and wing incidence and aileron position are apparently NOT the cause of this. Which means if we weigh& balance it agaain and it is NOT outside of the Kolb approved range... then you and me and everyone else is just about out of ideas. Unless Bryan Melborn knows something the rest of the Kolbers don't know, then everyone is out of ideas.I had also installed two small rudder trim tabs, which are 3/4 of the way to "fixing" the yaw trim. Today's test flight included some final approaches with little or no power. I paid attention to the rudder during these approaches,a nd sure enough the amount of left rudder needed is a lot less with little or no power. So my aircraft is not significantly "bent" or warped in the yaw directiton, the rudder trim issue is directly related to the engine and prop wash just like everyone suspected. So a rudder triim tab is an easy and obvious fix. Maybe someday in the future I will put the engine on at a different angle, but that will be after I have fun flying it for a while.Today's test flight also was equipped with a higher quality pitot and static probe, and it verified that the aircraft is making a lot more drag than it could be. 45 miles an hour cruise speed (downwind in the pattern) at 5600-5700 RPM. But I have not done any drag reduction on this aircraft yet, no fairings, no streamline struts, no tape over the control gaps, etc. etc. So I am guessing that I can find another 10-15 mph as I fiddle with the drag stuff. I was supposed to meet with the guy who did the weight and balance today but he had to postpone it till Friday. The only thing that would explain all of this aircraft's strange behavior is if it is REALLY tail-heavy, and I do not believe it is outside of the Kolb CG range.Anyway, again I REALLY appreciate everyone's interest and participation in trying to solve this puzzle. If any of the mroe highly experienced Kolb pilots want to come fly this aircraft themselves and try to figure it out, let me know.Bill Berlewww.ezflaphandle.com - safety & performance upgrade for light aircraftwww.grantstar.net - winning proposals for non-profit and for-profit entitiesOn Wed, 8/15/18, Bill <victorbravo(at)sbcglobal.net> wrote: Subject: Re: Kolb-List:Stabilizer Angle To: kolb-list(at)matronics.com Date: Wednesday, August 15, 2018, 11:56 AM Â --> Kolb-List message posted by: Bill <victorbravo(at)sbcglobal.net> Â Just spent 45 minutes on the phone with Duane at Kolb. Great guy! He also thinks the stabilizer should not be that high. He will show the pictures to Bryan. Â Â Sent from my Samsung Captivate(tm) on AT&T Â Bill <victorbravo(at)sbcglobal.net> wrote: --> Kolb-List message posted by: Bill <victorbravo(at)sbcglobal.net>I cannot find any reference in the 1993 plans that gives me the wing incidence angle. It shows "level" at 9 degrees for W&B but nothing about the angle between wing and fuselage.Sent from my Samsung Captivate(tm) on AT&TBill <victorbravo(at)sbcglobal.net> |
03579 | Quote: | | Quote: | | Quote: | | On Wed, 8/15/18, Bill <victorbravo(at)sbcglobal.net> wrote: Subject: Re: Kolb-List:Stabilizer Angle To: kolb-list(at)matronics.com Date: Wednesday, August 15, 2018, 11:56 AM Â --> Kolb-List message posted by: Bill <victorbravo(at)sbcglobal.net> Â Just spent 45 minutes on the phone with Duane at Kolb. Great guy! He also thinks the stabilizer should not be that high. He will show the pictures to Bryan. Â Â Sent from my Samsung Captivate(tm) on AT&T Â Bill <victorbravo(at)sbcglobal.net> wrote: |
0 | Quote: | | On Wed, 8/15/18, Bill <victorbravo(at)sbcglobal.net> wrote: Subject: Re: Kolb-List:Stabilizer Angle To: kolb-list(at)matronics.com Date: Wednesday, August 15, 2018, 11:56 AM Â --> Kolb-List message posted by: Bill <victorbravo(at)sbcglobal.net> Â Just spent 45 minutes on the phone with Duane at Kolb. Great guy! He also thinks the stabilizer should not be that high. He will show the pictures to Bryan. Â Â Sent from my Samsung Captivate(tm) on AT&T Â Bill <victorbravo(at)sbcglobal.net> wrote: |
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On Wed, 8/15/18, Bill <victorbravo(at)sbcglobal.net> wrote: Subject: Re: Kolb-List:Stabilizer Angle To: kolb-list(at)matronics.com Date: Wednesday, August 15, 2018, 11:56 AM Â --> Kolb-List message posted by: Bill <victorbravo(at)sbcglobal.net> Â Just spent 45 minutes on the phone with Duane at Kolb. Great guy! He also thinks the stabilizer should not be that high. He will show the pictures to Bryan. Â Â Sent from my Samsung Captivate(tm) on AT&T Â Bill <victorbravo(at)sbcglobal.net> wrote: |
2 | Quote: | | Quote: | | Quote: | | On Wed, 8/15/18, Bill <victorbravo(at)sbcglobal.net> wrote: Subject: Re: Kolb-List:Stabilizer Angle To: kolb-list(at)matronics.com Date: Wednesday, August 15, 2018, 11:56 AM Â --> Kolb-List message posted by: Bill <victorbravo(at)sbcglobal.net> Â Just spent 45 minutes on the phone with Duane at Kolb. Great guy! He also thinks the stabilizer should not be that high. He will show the pictures to Bryan. Â Â Sent from my Samsung Captivate(tm) on AT&T Â Bill <victorbravo(at)sbcglobal.net> wrote: |
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On Wed, 8/15/18, Bill <victorbravo(at)sbcglobal.net> wrote: Subject: Re: Kolb-List:Stabilizer Angle To: kolb-list(at)matronics.com Date: Wednesday, August 15, 2018, 11:56 AM Â --> Kolb-List message posted by: Bill <victorbravo(at)sbcglobal.net> Â Just spent 45 minutes on the phone with Duane at Kolb. Great guy! He also thinks the stabilizer should not be that high. He will show the pictures to Bryan. Â Â Sent from my Samsung Captivate(tm) on AT&T Â Bill <victorbravo(at)sbcglobal.net> wrote: |
4 | Quote: | | Quote: | | Quote: | | On Wed, 8/15/18, Bill <victorbravo(at)sbcglobal.net> wrote: Subject: Re: Kolb-List:Stabilizer Angle To: kolb-list(at)matronics.com Date: Wednesday, August 15, 2018, 11:56 AM Â --> Kolb-List message posted by: Bill <victorbravo(at)sbcglobal.net> Â Just spent 45 minutes on the phone with Duane at Kolb. Great guy! He also thinks the stabilizer should not be that high. He will show the pictures to Bryan. Â Â Sent from my Samsung Captivate(tm) on AT&T Â Bill <victorbravo(at)sbcglobal.net> wrote: |
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On Wed, 8/15/18, Bill <victorbravo(at)sbcglobal.net> wrote: Subject: Re: Kolb-List:Stabilizer Angle To: kolb-list(at)matronics.com Date: Wednesday, August 15, 2018, 11:56 AM Â --> Kolb-List message posted by: Bill <victorbravo(at)sbcglobal.net> Â Just spent 45 minutes on the phone with Duane at Kolb. Great guy! He also thinks the stabilizer should not be that high. He will show the pictures to Bryan. Â Â Sent from my Samsung Captivate(tm) on AT&T Â Bill <victorbravo(at)sbcglobal.net> wrote: |
6 | Quote: | | Quote: | | Quote: | | On Wed, 8/15/18, Bill <victorbravo(at)sbcglobal.net> wrote: Subject: Re: Kolb-List:Stabilizer Angle To: kolb-list(at)matronics.com Date: Wednesday, August 15, 2018, 11:56 AM Â --> Kolb-List message posted by: Bill <victorbravo(at)sbcglobal.net> Â Just spent 45 minutes on the phone with Duane at Kolb. Great guy! He also thinks the stabilizer should not be that high. He will show the pictures to Bryan. Â Â Sent from my Samsung Captivate(tm) on AT&T Â Bill <victorbravo(at)sbcglobal.net> wrote: |
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On Wed, 8/15/18, Bill <victorbravo(at)sbcglobal.net> wrote: Subject: Re: Kolb-List:Stabilizer Angle To: kolb-list(at)matronics.com Date: Wednesday, August 15, 2018, 11:56 AM Â --> Kolb-List message posted by: Bill <victorbravo(at)sbcglobal.net> Â Just spent 45 minutes on the phone with Duane at Kolb. Great guy! He also thinks the stabilizer should not be that high. He will show the pictures to Bryan. Â Â Sent from my Samsung Captivate(tm) on AT&T Â Bill <victorbravo(at)sbcglobal.net> wrote: |
8 | Quote: | | Quote: | | Quote: | | On Wed, 8/15/18, Bill <victorbravo(at)sbcglobal.net> wrote: Subject: Re: Kolb-List:Stabilizer Angle To: kolb-list(at)matronics.com Date: Wednesday, August 15, 2018, 11:56 AM Â --> Kolb-List message posted by: Bill <victorbravo(at)sbcglobal.net> Â Just spent 45 minutes on the phone with Duane at Kolb. Great guy! He also thinks the stabilizer should not be that high. He will show the pictures to Bryan. Â Â Sent from my Samsung Captivate(tm) on AT&T Â Bill <victorbravo(at)sbcglobal.net> wrote: |
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John Hauck
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victorbravo(at)sbcglobal.
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| Posted: Thu Aug 16, 2018 6:29 am Post subject: Kolb-List:Stabilizer Angle |
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To answer the recent questions...
Excellent idea about the wheel locations. That would have definitely skewed the equations a little. But we did in fact use the actual location of the main wheels, because the gear legs are very different than stock on tis aircraft. We put little pieces of tape on the ground under all three wheels and used the actual tape measure distances. So we did the weight and balance specifically to the measurements of this aircraft.
My HKS engine manual says the weight is 121 pounds including starter, alternator, gearbox, and OEM exhgaut/muffler system. My custom aluminum muffler weighs about the same as the stock steel can, but my muffler is definitely further behind the CG than the standard installation.
The engine angle is the same as whatever is welded into the Kolb mounts. There are no wedges or shims in my mounting system to alter the thrust line. I went to great lengths to have my thrust line as low as possible, so I did not have any pitch-forward problems. I managed to keep the gearbox turned "downward". I have a 65 inch diameter propeller, wihch has 7/8 of an inch clearance above the tailboom tube. So this puts the center of the thrust line 33.25 inches above the top surface of the tailboom tube. I do recall asking Bryan Melborn at Kolb about this distance, and he said that he would not want to be flyng a Kolb with the thrust line more than 36 inches above the tailboom. So I probably should be in the acceptable range.
I do have 3/4 of a gap seal between the wings. What I mean by that is that I have an aluminum "airfoil" shaped leading edgee piece that slides on from the front,a nd extends back to just behind the thickest part of the wing. This aluminum piece ends right at where the main spar pins are installed. THEN I have a fabric cover that Velcro's btween the wings from there to the rear carry-through where the wing fold U-joints are. The front of this fabric cover overlaps and Velcro's to the back of the aluminum piece. So there is not a huge hole where the air can flow upward between the wings. But there is nothing on the TOP of the wing behind the aluminum leading edge fairing and in front of the engine. Maybe 18 inches of wing chord with no cover on the TOP. All of the gap on the bottom is covered back to the wing fold U-joints.
Duane at Kolb asked me to verify that this is a Firestar 2. It is definitely a FS2, with the 7 rib wing and the "rear seat" area.
Anyway, as soon as we can go through the W&B calculations again I will copy and post them here so you guys can see them.
Bill Berle
www.ezflaphandle.com - safety & performance upgrade for light aircraft
www.grantstar.net      - winning proposals for non-profit and for-profit entities
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Rex Rodebush
Joined: 10 Jan 2006
Posts: 209
Location: Branson West area, Missouri
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| Posted: Thu Aug 16, 2018 7:49 am Post subject: Re: Kolb-List:Stabilizer Angle |
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Bill,
Rather than using the 3" measurement for the wing angle I think it would perhaps be worthwhile to find out the actual wing angle and stabilizer angle referenced from the motor mounts. If Kolb can't give that to you maybe someone with a good flying Firestar could give you the numbers.
(My Xtra had a wing angle procedure by leveling and measuring distances. Which I did. When I got Brian's actual recommended wing angle it was not the same. I reset to Brian's recommendations and my Xtra has flown great.)
Another thought. If the center of thrust has been changed (you said you lowered it), maybe that would affect the ideal wing angle? Maybe others have done that with no problems.
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