---------------------------------------------------------- Kolb-List Digest Archive --- Total Messages Posted Mon 08/13/18: 29 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:50 AM - Re: Stabilizer Angle (Bill Berle) 2. 03:19 AM - Re: Stabilizer Angle (racerjerry) 3. 05:05 AM - Re: Stabilizer Angle (Richard Pike) 4. 06:26 AM - Re: Stabilizer Angle (Denny Baber) 5. 06:46 AM - Re: Stabilizer Angle (Denny Baber) 6. 06:47 AM - Re: Stabilizer Angle (George Helton) 7. 06:48 AM - Re: Stabilizer Angle (Bill Berle) 8. 08:14 AM - Re: Stabilizer Angle (Jerry-TS-MkII) 9. 09:00 AM - Re: Stabilizer Angle (John Hauck) 10. 09:03 AM - Re: Flutter / Firestar Test Flight #2 (Mcabbage) 11. 09:28 AM - Re: Re: Flutter / Firestar Test Flight #2 (John Hauck) 12. 10:17 AM - Re: Stabilizer Angle (Frankd) 13. 10:28 AM - Re: Re: Flutter / Firestar Test Flight #2 (Charlie England) 14. 11:30 AM - Re: Re: Flutter / Firestar Test Flight #2 (John Hauck) 15. 02:47 PM - Re: Stabilizer Angle (Richard Pike) 16. 02:54 PM - Re: Stabilizer Angle (Bill) 17. 02:58 PM - Re: Stabilizer Angle (Bill) 18. 03:32 PM - Re: Stabilizer Angle (B Young) 19. 04:31 PM - Re: Stabilizer Angle (Larry Cottrell) 20. 05:30 PM - Photo Sizes (John Hauck) 21. 05:36 PM - Re: Stabilizer Angle (John Hauck) 22. 05:42 PM - Re: Stabilizer Angle (John Hauck) 23. 05:44 PM - Re: Stabilizer Angle (Larry Cottrell) 24. 05:49 PM - Re: Stabilizer Angle (John Hauck) 25. 05:50 PM - Re: Stabilizer Angle (John Hauck) 26. 06:10 PM - Re: Stabilizer Angle (George Helton) 27. 06:52 PM - Re: Stabilizer Angle (John Hauck) 28. 07:05 PM - Re: Stabilizer Angle (George Helton) 29. 11:04 PM - Re: Stabilizer Angle (Bill Berle) ________________________________ Message 1 _____________________________________ Time: 12:50:36 AM PST US From: Bill Berle Subject: Re: Kolb-List:Stabilizer Angle -------------------------------------------- On Sun, 8/12/18, Charlie England 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? ________________________________ Message 2 _____________________________________ Time: 03:19:11 AM PST US Subject: Re: Kolb-List:Stabilizer Angle From: "racerjerry" Where the heck are you getting the aft C/G limit figure of 43%? Quote from my Firestar book (transition period between Firestar I & Firestar II) page 74: "... the airplane will be safe to fly if the center of gravity is between 20% and 35% of wing chord as measured from the leading edge." The Weight & Balance Calculation diagram on my plans page 26 stretches the aft limit to 37%. In my opinion, with anything beyond this you are flirting with death. BTW, I shortened the tail boom on my Firestar II one foot which resulted in completely neutral pitch forces on mine (always flown solo). Interesting to hear of different results. Jerry King -------- Jerry King Read this topic online here: http://forums.matronics.com/viewtopic.php?p=482342#482342 ________________________________ Message 3 _____________________________________ Time: 05:05:24 AM PST US Subject: Re: Kolb-List:Stabilizer Angle From: "Richard Pike" Here is a copy of the Yellow Book, scroll down to pages 41-43. http://oh2fly.net/oldpoops/Lexan%20rear%20enclosure.html CG must fall between 20% and 37%. -------- Richard Pike Kolb MKIII N420P (420ldPoops) Kingsport, TN 3TN0 Forgiving is tough, being forgiven is wonderful, and God's grace really is amazing. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=482343#482343 ________________________________ Message 4 _____________________________________ Time: 06:26:30 AM PST US From: Denny Baber Subject: Re: Kolb-List: Kolb-List:Stabilizer Angle When you lower the ailerons, you are lowering the rear of the chord for that wing section and the increased angle of attack produces more lift. It is the same on the ailerons and the flaps. The flaps work in the same direction, the ailerons operate opposite so we operate around one axis with the flaps and another axis with the ailerons. The opposite of lift is drag so we also change the trim. You are usually right so I read it as being correct. But I also agree with whoever said that these are *experimental *and instead of overthinking it, like Nike says, "Just do it". If it doesn't work one way, try the other way. All the crashes I have heard of that are mechanical failures have not been from adjustment. So get out there and EXPERIMENT until you can fly hands off. We are the owners of these planes and the FAA has agreed to let us experiment on them if we don't kill anyone else. I appreciate the freedom from certified or anyone's opinion. Respectfully, Dennis Baber Cape Coral, Fl baberdk@gmail.com 305-814-7218 Stay Curious ________________________________ Message 5 _____________________________________ Time: 06:46:51 AM PST US From: Denny Baber Subject: Re: Kolb-List: Kolb-List:Stabilizer Angle Drooping the ailerons will increase angle of attack which increases lift. Respectfully, Dennis Baber Cape Coral, Fl baberdk@gmail.com 305-814-7218 Stay Curious ________________________________ Message 6 _____________________________________ Time: 06:47:13 AM PST US From: George Helton Subject: Re: Kolb-List: Kolb-List:Stabilizer Angle Just one thing. The opposite of lift is gravity. The opposite drag is thrust . But, I know what you were trying to refer to or say. George H. Firestar Mesick, Michigan Sent from my iPhone > On Aug 13, 2018, at 9:24 AM, Denny Baber wrote: > > When you lower the ailerons, you are lowering the rear of the chord for th at wing section and the increased angle of attack produces more lift. It is t he same on the ailerons and the flaps. The flaps work in the same direction, the ailerons operate opposite so we operate around one axis with the flaps a nd another axis with the ailerons. The opposite of lift is drag so we also c hange the trim. You are usually right so I read it as being correct. But I a lso agree with whoever said that these are experimental and instead of overt hinking it, like Nike says, "Just do it". If it doesn't work one way, try th e other way. All the crashes I have heard of that are mechanical failures ha ve not been from adjustment. So get out there and EXPERIMENT until you can f ly hands off. We are the owners of these planes and the FAA has agreed to le t us experiment on them if we don't kill anyone else. I appreciate the freed om from certified or anyone's opinion. > > > Respectfully, > Dennis Baber > Cape Coral, Fl > baberdk@gmail.com > 305-814-7218 > > Stay Curious > > ________________________________ Message 7 _____________________________________ Time: 06:48:54 AM PST US From: Bill Berle Subject: Re: Kolb-List: Kolb-List:Stabilizer Angle Forgive me if my memory is not perfect on that CG range number. I remember it was a number that was greater than most of the CG ranges found on light aircraft. My point was that when we did the weight and balance my aircraft WAS found to be within the safe range specified in the plans, whatever that number is. If it was close to the rear limit on the day we weighed it, and if I have miraculously lost more weight than I expected since then... then we will re-calculate it and see if I am still within the specified range. If my aircraft is outside of the range specified by Kolb, then I will have to move things around and make it safe to fly. I will not intentionally fly this aircraft outside of the Kolb specified CG range. The only time I have ever done that type of experimentation in an aircraft was under controlled conditions with a parachute, and the CG was able to be moved in flight once I was at a safe altitude. I don't have that capability with the Kolb, and I'm not going off to fly in national competitions, and sadly I'm not an indestructible 26 year old kid anymore. Bill Berle www.ezflaphandle.com - safety & performance upgrade for light aircraft www.grantstar.net - winning proposals for non-profit and for-profit entities ________________________________ Message 8 _____________________________________ Time: 08:14:59 AM PST US Subject: Re: Kolb-List:Stabilizer Angle From: "Jerry-TS-MkII" <12flybellaire@gmail.com> I've been following this post... (and no, I'm not a engineer either! LOL). But I have been a EAA member since the Rockford days, and have read every Sport Aviation, and lots of other aircraft and design related books. Have worked avionics, helped rebuild 3 GA planes, and worked on several home-builts including my own Bellaire SE. So.. just a few comments. I do agree that W&B should be checked. And I'd recommend you have a helper, so that you can climb into the plane, and check it that way as well. It's always hard to know where the weight datum is located on a large body, with arms and legs. I'll describe the generic way to do so, below. But I agree, that rearward CG is very dangerous. However, you have not mentioned any bad flight characteristics (in normal flight). Too far aft, it will become un-stable.. and then un-flyable. I wouldn't recommend doing any stalls at this point. And it's quite easy to add some weight in the nose. I helped a guy fly a Hummer, and he weighed about 90 lbs. We secured lead inside the forward foot support cross bar, to compensate for his very light weight. When using the term "wing chord" as the basis for the percentages for a acceptable CG range.. I'd find out from KOLB if that is between the leading and trailing tubes, or including the aileron chord too. Makes a big difference. Or just ask them the distance back from the leading edge. A forward CG is rarely a problem.. so I'd think moving it forward with some (temporary, but well secured) nose weight would be prudent, and may help resolve the problem. "Center of pressure" develops pitching moments, which are different for any given airfoil. And it changes (typically) with the angle of attack. So to verify all of that for sure, take a close look at the rib profile. You "could have" a "user modification" with a different airfoil. In light of the characteristics mentioned, I'd mount a Go-pro above the wing, to observe it, while making a near take-off run. (Ie wing is loaded and lifting). Make sure you do not have fabric that is either loose, or stretching with flight loads, causing the airfoil to be different than what was prescribed in the plans. That would include checking or observing the covering attachment to the stabilizer (top and bottom!!). Have you checked the geometry of the tail boom relative to the wing incidence? I've seen bent Kolbs before, but I'd think that would be obvious. I agree with you.. while trim tabs are wonderful, yours would be the size of your elevator!! They are intended to only slightly modify the elevator position in flight with a opposite deflection.. and not to resolve major "problems". Generic W&B. If you know the normal flight angle, (probably 3-4 positive angle of attack).. make a support for your tail wheel scale, so that on 3 scales, it is in the normal flying stance. Pick a datum point.. say the very nose of the plane. Plumb bob from there, to measure back to the position of the axles, and to the center of the tail wheel. Multiply the length in inches x the (two weights) for the mains, and do the same for the tail. Adding the weights, gives you the AC weight, and adding the two products together gives you the lever arm. Divide that by the total weight. The answer will be the balance point in inches back from the same nose (datum point). Just an example: Nose to main axles 48" x 500# = 24000 in/lbs Nose to tail wheel 192" x 25# = 4800 in/lbs Total weight 525. total lever arm 28800... 28800/525 = CG at 54.85" from the nose. Measure from the nose to the Leading Edge (and subtract that distance), and compare the remainder with the chord, for the percentage of the chord. If you add a pilot, do the same measurements, add in the weight and arm, TOW goes up, and the CG will change. So.. I'd suggest you put fuel in it, and YOU, and have someone else take the readings. 20-30% of the chord would seem to be much safer than 43%. Acrobatic planes push the CG rearward, so they snap roll more quickly! While we are all flying "Experimental" aircraft with Kolbs.. it is a well established design. Tweaking is fine, if something is new and unknown, or only slightly off. But it would appear (I believe) to everyone on the list.. something is "wrong" with your plane.. and needs correction, not just tweaking, or a trim tab. If the solution does not become obvious, with all of the input from the forum, you may want to find some local EAA guys to take a look at it.. something seems to be amiss.. and we're all wanting you to keep complaining about heavy ailerons for a long time! ;-) Jerry Twin Star MK II (rework at present) Read this topic online here: http://forums.matronics.com/viewtopic.php?p=482348#482348 ________________________________ Message 9 _____________________________________ Time: 09:00:29 AM PST US From: "John Hauck" Subject: RE: Kolb-List:Stabilizer Angle In all my years I have never seen or heard of a Kolb that had a cg problem unless there were major changes to the design or a bunch of weight was placed too far aft or too far forward. It just doesn't happen. How tight the fabric is shrunk, especially the bottom and the top of the wing has got to change flight characteristics. I shrink mine until it starts bending tubes. When you look at your wing bottom while sitting on the ground it is nice and flat. It does not stay that way once it is loaded. The looser the fabric the more concave the bottom of the wing in flight. I really do not know what flight characteristic this changes, but I have a gut feeling it does. If it was my problem I'd be taking measurements of everything. Start out with wing incidence. Someone help me here. I'm thinking more wing incidence causes the aircraft to climb excessively. I don't know. Some of you smarter Kolbers help me out. I'm not a Kolb expert, and don't mind admitting when I am wrong or if I don't know something. Asking questions helps get me educated. Something ain't right with Berle's Kolb. All he has to do is find it and correct it. One thing Berle said blows my mind. I do not comprehend the following. Excessive adverse pitch up while flying, but he used aft stick when landing. Can't wrap my head around that one. Anxious to find out what the "real" problem is. When I first started flying Kolbs I had a lot to learn about this unique aircraft. I had no fixed wing training on top of that. I must have been a good fixed wing IP (instructor pilot) because I didn't kill myself. ;-) john h mkIII Titus, Alabama ________________________________ Message 10 ____________________________________ Time: 09:03:55 AM PST US Subject: Kolb-List: Re: Flutter / Firestar Test Flight #2 From: "Mcabbage" Excellent discussion, im not trying to hijack your post Bill but may i ask as a zero time Kolb pilot what is the proper way to fly and land an engine out Kolb? Thanks Mike -------- 2007 Firestar 2 503 N203SD Moster 185 Flattop PPG/Sky K2 Paraglider Trike Buggy Soaring Trike & Northwing Stratus XP Read this topic online here: http://forums.matronics.com/viewtopic.php?p=482350#482350 ________________________________ Message 11 ____________________________________ Time: 09:28:45 AM PST US From: "John Hauck" Subject: RE: Kolb-List: Re: Flutter / Firestar Test Flight #2 Not much different than powered landing. Only thing is you don't get a second chance to do it. The Kolb will glide better dead stick and with the engine at idle. We should all be constantly looking for forced landing areas as we fly. Most likely the engine will quit when you least expect it, not necessarily when you have a nice big hay field to land in. If you can shoot your approach at idle all the way to the ground, you can do a dead stick. I've been flying 50 years next month. I still practice engine failures with dead stick landings. When the time comes I want to be able to execute the forced landing with ease. john h mkIII Titus, Alabama Excellent discussion, im not trying to hijack your post Bill but may i ask as a zero time Kolb pilot what is the proper way to fly and land an engine out Kolb? Thanks Mike -------- 2007 Firestar 2 503 N203SD ________________________________ Message 12 ____________________________________ Time: 10:17:43 AM PST US Subject: Re: Kolb-List:Stabilizer Angle From: "Frankd" Hello Bill/Kolbers, I have been following this thread from the beginning. When I saw your photos I was reminded of my MkIII Xtra where I had followed the factory instructions and later had to adjust the front mount of the Horizontal Stabs to be level with the top of the Boom tube. But not as high as yours. I also got a set of the wider universal joints to raise the Trailing edge of the wings about 1inch. Your wings look like they are set at a very high angle (Yes , your wheels make it look high) and your Horz Stabs are not far from that same angle. As well as checking your CG, I would also verify the Angle of attack of your wings and how your tail should be in relation to your wing on any plans you have . I believe your elevator should be producing a down force that counters the high engine thrust line. See the attached photo of the wide universal joint KOLB made for me. FrankD 1014S. Do not archive Read this topic online here: http://forums.matronics.com/viewtopic.php?p=482354#482354 Attachments: http://forums.matronics.com//files/wing_lift_193.jpg ________________________________ Message 13 ____________________________________ Time: 10:28:26 AM PST US Subject: Re: Kolb-List: Re: Flutter / Firestar Test Flight #2 From: Charlie England Amen to that. When I did my training for my private ticket (in a not-Kolb), I was fortunate to have an instructor that made me treat every landing as an engine-out. I had to be at idle at pattern altitude abeam the numbers, and make the landing work from there. I realize that going to idle that early isn't likely to work in a Kolb, but carrying power into the flair on every landing is a sure-fire way to guarantee a bent plane (and maybe broken people) the 1st time the engine actually fails. That's true no matter what you fly, unless it has turbine power. Charlie On 8/13/2018 11:28 AM, John Hauck wrote: > > Not much different than powered landing. Only thing is you don't get a > second chance to do it. The Kolb will glide better dead stick and with the > engine at idle. > > We should all be constantly looking for forced landing areas as we fly. > Most likely the engine will quit when you least expect it, not necessarily > when you have a nice big hay field to land in. > > If you can shoot your approach at idle all the way to the ground, you can do > a dead stick. > > I've been flying 50 years next month. I still practice engine failures with > dead stick landings. When the time comes I want to be able to execute the > forced landing with ease. > > john h > mkIII > Titus, Alabama > > > > Excellent discussion, im not trying to hijack your post Bill > but may i ask as a zero time Kolb pilot what is the proper way to fly > and land an engine out Kolb? > Thanks Mike > > -------- > 2007 Firestar 2 503 N203SD > > > --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus ________________________________ Message 14 ____________________________________ Time: 11:30:04 AM PST US From: "John Hauck" Subject: RE: Kolb-List: Re: Flutter / Firestar Test Flight #2 I forget how many landings I've done in my MKIII, 7 or 8 thousand. Too lazy to get up. Now I see my log books on the end of my desk. In my mkIII alone, 7,302 landings, not counting multiple landings from bounces. Not counting landings in other Kolbs. All those landings were idle engine unless I was in a Hell of a wind and needed some power to help the rudder kick the tail around. Not hard for a good wind to overpower the rudder at idle. Doesn't count landings in my Ultrastar and Firestar. I started shooting landings at idle from the get go in the US. It was just the natural thing to do, to me. Back then we experienced a lot of engine outs, and I wanted to be prepared. Got my Private Ticket in a 152, 22 years after Army Rotary Wing Training and 16 years after I started flying Kolbs. I was getting ready to build a two place Kolb. Don't know how many landings in the US and FS, but I did get 1150.0 hours in both aircraft in less than 5 years. I was pretty hard on those airplanes confronted with a steep learning curve. There were a couple years of down time to repair, and another complete rebuild down to bare steel on the fuselage and other steel parts. I was a flying fool back then. I was taught idle power landings in the 152. What were we talking about? Sorry, I got carried away again. john h mkIII Titus, Alabama Amen to that. When I did my training for my private ticket (in a not-Kolb), I was fortunate to have an instructor that made me treat every landing as an engine-out. I had to be at idle at pattern altitude abeam the numbers, and make the landing work from there. I realize that going to idle that early isn't likely to work in a Kolb, but carrying power into the flair on every landing is a sure-fire way to guarantee a bent plane (and maybe broken people) the 1st time the engine actually fails. That's true no matter what you fly, unless it has turbine power. Charlie ________________________________ Message 15 ____________________________________ Time: 02:47:27 PM PST US Subject: Re: Kolb-List:Stabilizer Angle From: "Richard Pike" Even though Frankd does not have Image Resizer (poor chap - blew the page dimensions all to pot wit da giant pitchur) https://www.bricelam.net/ImageResizer/ he does bring up a good point: if your wing and your horizontal stab have the wrong angle between them, it causes problems. There is an app for Android phones called "Bubble Level" - it seems to be accurate to 1/10 of a degree. Went out and checked my MKIII; stab leading edge bracket is right to plans, main spar attach point is right to plans. The underside of the wing measured along a rib bottom was at an angle of 8.3 degrees. The root tube of the horizontal stab was at .3 degrees. Exactly 8 degrees of difference between the bottom of the wing and the horizontal stab. Don't know if that is what it is supposed to be, but my MKIII has always been easy to fly, trim, etc. At least it is known to behave acceptably, which gives us all something to work from. Worth what ya paid fer it. So Brother Berle - How about you download Bubble Level onto your smart phone, go check your wing and tail, and let us know what ya got. -------- Richard Pike Kolb MKIII N420P (420ldPoops) Kingsport, TN 3TN0 Forgiving is tough, being forgiven is wonderful, and God's grace really is amazing. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=482358#482358 ________________________________ Message 16 ____________________________________ Time: 02:54:55 PM PST US Subject: RE: Kolb-List:Stabilizer Angle From: Bill To answer one of the questions raised, my decalage angle is 4 degrees. With wings level the stabilizer is 4 degrees nose down (with the new tall extensions). This seems reasonable. Sent from my Samsung Captivate(tm) on AT&T John Hauck wrote: > > > In all my years I have never seen or heard of a Kolb that had a cg problem >unless there were major changes to the design or a bunch of weight was >placed too far aft or too far forward. It just doesn't happen. > >How tight the fabric is shrunk, especially the bottom and the top of the >wing has got to change flight characteristics. I shrink mine until it >starts bending tubes. When you look at your wing bottom while sitting on >the ground it is nice and flat. It does not stay that way once it is >loaded. The looser the fabric the more concave the bottom of the wing in >flight. I really do not know what flight characteristic this changes, but I >have a gut feeling it does. > >If it was my problem I'd be taking measurements of everything. Start out >with wing incidence. Someone help me here. I'm thinking more wing >incidence causes the aircraft to climb excessively. I don't know. Some of >you smarter Kolbers help me out. I'm not a Kolb expert, and don't mind >admitting when I am wrong or if I don't know something. Asking questions >helps get me educated. > >Something ain't right with Berle's Kolb. All he has to do is find it and >correct it. > >One thing Berle said blows my mind. I do not comprehend the following. >Excessive adverse pitch up while flying, but he used aft stick when landing. >Can't wrap my head around that one. > >Anxious to find out what the "real" problem is. When I first started flying >Kolbs I had a lot to learn about this unique aircraft. I had no fixed wing >training on top of that. I must have been a good fixed wing IP (instructor >pilot) because I didn't kill myself. ;-) > > >john h >mkIII >Titus, Alabama > > ________________________________ Message 17 ____________________________________ Time: 02:58:00 PM PST US Subject: RE: Kolb-List:Stabilizer Angle From: Bill Also the distance from the attach bolt at the fuselage cage to the rear edge of the fuselage tube (inside the steel ring) at the rear is 10 ft 6 in. Sent from my Samsung Captivate(tm) on AT&T John Hauck wrote: > > > In all my years I have never seen or heard of a Kolb that had a cg problem >unless there were major changes to the design or a bunch of weight was >placed too far aft or too far forward. It just doesn't happen. > >How tight the fabric is shrunk, especially the bottom and the top of the >wing has got to change flight characteristics. I shrink mine until it >starts bending tubes. When you look at your wing bottom while sitting on >the ground it is nice and flat. It does not stay that way once it is >loaded. The looser the fabric the more concave the bottom of the wing in >flight. I really do not know what flight characteristic this changes, but I >have a gut feeling it does. > >If it was my problem I'd be taking measurements of everything. Start out >with wing incidence. Someone help me here. I'm thinking more wing >incidence causes the aircraft to climb excessively. I don't know. Some of >you smarter Kolbers help me out. I'm not a Kolb expert, and don't mind >admitting when I am wrong or if I don't know something. Asking questions >helps get me educated. > >Something ain't right with Berle's Kolb. All he has to do is find it and >correct it. > >One thing Berle said blows my mind. I do not comprehend the following. >Excessive adverse pitch up while flying, but he used aft stick when landing. >Can't wrap my head around that one. > >Anxious to find out what the "real" problem is. When I first started flying >Kolbs I had a lot to learn about this unique aircraft. I had no fixed wing >training on top of that. I must have been a good fixed wing IP (instructor >pilot) because I didn't kill myself. ;-) > > >john h >mkIII >Titus, Alabama > > ________________________________ Message 18 ____________________________________ Time: 03:32:16 PM PST US From: B Young Subject: Re: Kolb-List:Stabilizer Angle When using the term "wing chord" as the basis for the percentages for a acceptable CG range.. I'd find out from KOLB if that is between the leading and trailing tubes, or including the aileron chord too. ************************* Checked the plans for my mkiii c... Front of Leading edge to the rear of trailing edge is 50. 5/8. W&B page says to use 66 for figuring the % of CG which should be between 25% and 35 % With these numbers I've concluded that % of wing cord includes ailerons and flaps Boyd Young Mkiii c Utah ________________________________ Message 19 ____________________________________ Time: 04:31:15 PM PST US From: Larry Cottrell Subject: Re: Kolb-List:Stabilizer Angle Measured my firestar 2 and it is 8 degrees difference as well. Larry On Mon, Aug 13, 2018 at 3:49 PM Richard Pike wrote: > > Even though Frankd does not have Image Resizer (poor chap - blew the page > dimensions all to pot wit da giant pitchur) > https://www.bricelam.net/ImageResizer/ > he does bring up a good point: if your wing and your horizontal stab have > the wrong angle between them, it causes problems. > > There is an app for Android phones called "Bubble Level" - it seems to be > accurate to 1/10 of a degree. Went out and checked my MKIII; stab leading > edge bracket is right to plans, main spar attach point is right to plans. > The underside of the wing measured along a rib bottom was at an angle of > 8.3 degrees. > The root tube of the horizontal stab was at .3 degrees. > Exactly 8 degrees of difference between the bottom of the wing and the > horizontal stab. > > Don't know if that is what it is supposed to be, but my MKIII has always > been easy to fly, trim, etc. At least it is known to behave acceptably, > which gives us all something to work from. > > Worth what ya paid fer it. > > So Brother Berle - How about you download Bubble Level onto your smart > phone, go check your wing and tail, and let us know what ya got. > > -------- > Richard Pike > Kolb MKIII N420P (420ldPoops) > Kingsport, TN 3TN0 > > Forgiving is tough, being forgiven is wonderful, and God's grace really is > amazing. > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=482358#482358 > > -- *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.* ________________________________ Message 20 ____________________________________ Time: 05:30:21 PM PST US From: "John Hauck" Subject: Kolb-List: Photo Sizes I don't seem to have the same problem as Richard. All photos are downloaded and posted the correct size. I think most computers, now days, do that. Every once in a while I get a "lopper" that flows right off the margins and I can't make heads nor tails about it. In that case I don't look at it. If it is important I'll contact the sender and ask him to resize and resend me a copy if he wants me to see it. Check and see why your computer is not automatically resizing. I know I can't have the only computer, actually two computers, that resize. john h mkIII Titus, Alabama Even though Frankd does not have Image Resizer (poor chap - blew the page dimensions all to pot wit da giant pitchur) https://www.bricelam.net/ImageResizer/ he does bring up a good point: if your wing and your horizontal stab have the wrong angle between them, it causes problems. -------- Richard Pike ________________________________ Message 21 ____________________________________ Time: 05:36:22 PM PST US From: "John Hauck" Subject: RE: Kolb-List:Stabilizer Angle What is the total length supposed to be for your model Kolb? I don't think tail boom length is the root of your problem, but I don't know for sure. john h mkIII Titus, Alabama Also the distance from the attach bolt at the fuselage cage to the rear edge of the fuselage tube (inside the steel ring) at the rear is 10 ft 6 in. ________________________________ Message 22 ____________________________________ Time: 05:42:26 PM PST US From: "John Hauck" Subject: RE: Kolb-List:Stabilizer Angle Ya'll may be on to something. Since Bill B, also known as BB, hacked his up he is only half that distance. john h mkIII Titus, Alabama From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of Larry Cottrell Sent: Monday, August 13, 2018 6:31 PM Subject: Re: Kolb-List:Stabilizer Angle Measured my firestar 2 and it is 8 degrees difference as well. Larry ________________________________ Message 23 ____________________________________ Time: 05:44:32 PM PST US From: Larry Cottrell Subject: Re: Kolb-List:Stabilizer Angle My Firestar II measures 10.6 inches as well. So his tube is not shortened. Larry On Mon, Aug 13, 2018 at 6:37 PM John Hauck wrote: > > What is the total length supposed to be for your model Kolb? > > I don't think tail boom length is the root of your problem, but I don't > know for sure. > > john h > mkIII > Titus, Alabama > > > > Also the distance from the attach bolt at the fuselage cage to the rear > edge of the fuselage tube (inside the steel ring) at the rear is 10 ft 6 in. > > -- *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.* ________________________________ Message 24 ____________________________________ Time: 05:49:41 PM PST US From: "John Hauck" Subject: RE: Kolb-List:Stabilizer Angle I just got in from mounting a couple 14 ply trailer tires on my 5th wheel. I know better than to try and write an email when I'm that pooped. My one line msg should have read: jacked his up, not hacked his up. ;-) Bill B may not think that's funny, but it was an honest mistake. As we used to say in VN, "Sin Loi" or "Sorry about that". john h mkIII Titus, Alabama From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of John Hauck Sent: Monday, August 13, 2018 7:40 PM Subject: RE: Kolb-List:Stabilizer Angle Ya'll may be on to something. Since Bill B, also known as BB, hacked his up he is only half that distance. john h mkIII Titus, Alabama ________________________________ Message 25 ____________________________________ Time: 05:50:47 PM PST US From: "John Hauck" Subject: RE: Kolb-List:Stabilizer Angle Don't have to worry about tail boom anymore. john h mkIII Titus, Alabama From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of Larry Cottrell Sent: Monday, August 13, 2018 7:44 PM Subject: Re: Kolb-List:Stabilizer Angle My Firestar II measures 10.6 inches as well. So his tube is not shortened. Larry ________________________________ Message 26 ____________________________________ Time: 06:10:30 PM PST US From: George Helton Subject: Re: Kolb-List:Stabilizer Angle Yeah John, I think Bill should just go back to square one. Put everything ba ck the way it was and take your original advice. Droop the ailerons and don =99t 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 wrote: > > Don't have to worry about tail boom anymore. > > john h > mkIII > Titus, Alabama > > From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@ matronics.com] On Behalf Of Larry Cottrell > Sent: Monday, August 13, 2018 7:44 PM > To: kolb-list@matronics.com > Subject: Re: Kolb-List:Stabilizer Angle > > My Firestar II measures 10.6 inches as well. So his tube is not shortened. > Larry > ________________________________ Message 27 ____________________________________ Time: 06:52:28 PM PST US From: "John Hauck" Subject: RE: Kolb-List:Stabilizer Angle 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@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of George Helton Sent: Monday, August 13, 2018 8:10 PM 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=99t 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 wrote: Don't have to worry about tail boom anymore. john h mkIII Titus, Alabama From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of Larry Cottrell Sent: Monday, August 13, 2018 7:44 PM Subject: Re: Kolb-List:Stabilizer Angle My Firestar II measures 10.6 inches as well. So his tube is not shortened. Larry ________________________________ Message 28 ____________________________________ Time: 07:05:30 PM PST US From: George Helton Subject: Re: Kolb-List:Stabilizer Angle I agreed, the transition to Kolbs can take a bit of time. Especially if you h aven=99t any experience ultralights before. Oh well, I think I=99ll 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 wrote: > > I don't know. > > What blows my mind is the adverse nose up pitch, but BB said he used aft s tick 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 doe sn'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 s ure 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 characteri stics to know what to look for. It's going to take a bit of time in the coc kpit to learn the aircraft. Not easy to fix an airplane if you don't know w hat 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@matronics.com [mailto:owner-kolb-list-server@ matronics.com] On Behalf Of George Helton > Sent: Monday, August 13, 2018 8:10 PM > To: kolb-list@matronics.com > Subject: Re: Kolb-List:Stabilizer Angle > > Yeah John, I think Bill should just go back to square one. Put everything b ack the way it was and take your original advice. Droop the ailerons and don =99t 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 wrote: > > Don't have to worry about tail boom anymore. > > john h > mkIII > Titus, Alabama > > From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@ matronics.com] On Behalf Of Larry Cottrell > Sent: Monday, August 13, 2018 7:44 PM > To: kolb-list@matronics.com > Subject: Re: Kolb-List:Stabilizer Angle > > My Firestar II measures 10.6 inches as well. So his tube is not shortened. > Larry > ________________________________ Message 29 ____________________________________ Time: 11:04:01 PM PST US From: Bill Berle Subject: RE: Kolb-List:Stabilizer Angle 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 wrote: Subject: RE: Kolb-List:Stabilizer Angle To: kolb-list@matronics.com Date: Monday, August 13, 2018, 6:52 PM #yiv2727135594 #yiv2727135594 -- _filtered #yiv2727135594 {panose-1:2 4 5 3 5 4 6 3 2 4;} _filtered #yiv2727135594 {font-family:Calibri;panose-1:2 15 5 2 2 2 4 3 2 4;} _filtered #yiv2727135594 {font-family:Tahoma;panose-1:2 11 6 4 3 5 4 4 2 4;} #yiv2727135594 #yiv2727135594 p.yiv2727135594MsoNormal, #yiv2727135594 li.yiv2727135594MsoNormal, #yiv2727135594 div.yiv2727135594MsoNormal {margin:0in;margin-bottom:.0001pt;font-size:12.0pt;font-family:New;} #yiv2727135594 a:link, #yiv2727135594 span.yiv2727135594MsoHyperlink {color:blue;text-decoration:underline;} #yiv2727135594 a:visited, #yiv2727135594 span.yiv2727135594MsoHyperlinkFollowed {color:purple;text-decoration:underline;} #yiv2727135594 span.yiv2727135594EmailStyle17 {color:#1F497D;} #yiv2727135594 span.yiv2727135594EmailStyle18 {color:#1F497D;} #yiv2727135594 .yiv2727135594MsoChpDefault {font-size:10.0pt;} _filtered #yiv2727135594 {margin:1.0in 1.0in 1.0in 1.0in;} #yiv2727135594 div.yiv2727135594WordSection1 {} #yiv2727135594 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 hmkIIITitus, Alabama From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of George Helton Sent: Monday, August 13, 2018 8:10 PM To: kolb-list@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 dont try to figure out why. I think in the long run it will be aft c/g.George H.FirestarMesick, MichiganSent from my iPhone On Aug 13, 2018, at 8:50 PM, John Hauck wrote:Don't have to worry about tail boom anymore.john hmkIIITitus, AlabamaFrom: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of Larry Cottrell Sent: Monday, August 13, 2018 7:44 PM To: kolb-list@matronics.com Subject: Re: Kolb-List:Stabilizer AngleMy Firestar II measures 10.6 inches as well. So his tube is not shortened.Larry ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message kolb-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Kolb-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/kolb-list Browse Digests http://www.matronics.com/digest/kolb-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.