---------------------------------------------------------- Kolb-List Digest Archive --- Total Messages Posted Tue 12/14/04: 52 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:56 AM - 503 losing power (wmtatham@juno.com) 2. 05:11 AM - Re: Fair price for used 912S? (Rusty) 3. 05:11 AM - Re: First WetFly Flight (Rusty) 4. 05:51 AM - Re: mo CG (PATRICK LADD) 5. 05:56 AM - rotax/rotary exchange (woody) 6. 05:56 AM - Re: Fw: Rotax Price Increases (woody) 7. 06:15 AM - Re: Fw: Rotax Price Increases (Rusty) 8. 06:31 AM - Re: Fw: Rotax Price Increases (Larry Bourne) 9. 06:32 AM - Re: mo CG (robert bean) 10. 06:32 AM - Re: mo CG (Denny Rowe) 11. 06:35 AM - Re: Weight and Balance (snuffy@usol.com) 12. 06:36 AM - Re: mo CG (Larry Bourne) 13. 06:40 AM - Re: Fw: Rotax Price Increases (Larry Bourne) 14. 06:44 AM - Re: mo CG (snuffy@usol.com) 15. 06:48 AM - Re: mo CG (Creech, Lee (Local Govt)) 16. 06:50 AM - Re: Weight and Balance (John Hauck) 17. 06:53 AM - Re: Fw: Rotax Price Increases (John Hauck) 18. 07:30 AM - C of G (PATRICK LADD) 19. 07:33 AM - Re: Weight and Balance (Kirby Dennis Contr MDA/AL) 20. 07:35 AM - Re: Weight and Balance (PATRICK LADD) 21. 07:51 AM - Re: mo CG (PATRICK LADD) 22. 08:00 AM - Re: Verner Mark-III Update (William George) 23. 08:10 AM - Re: Re: Weight and Balance (jhauck@elmore.rr.com) 24. 08:10 AM - Re: C of G (jhauck@elmore.rr.com) 25. 08:14 AM - Re: mo CG (snuffy@usol.com) 26. 08:15 AM - Re: mo CG (PATRICK LADD) 27. 08:17 AM - Re: Re: mo CG (jhauck@elmore.rr.com) 28. 08:19 AM - Re: mo CG (Richard Pike) 29. 08:55 AM - Re: Tail Heavy Firestar (David Paule) 30. 09:32 AM - Re: mo CG (ray anderson) 31. 11:55 AM - Re: Tail Heavy Firestar (David Paule) 32. 01:58 PM - Re: First WetFly Flight (N27SB@aol.com) 33. 02:17 PM - Aero Engineer (Mike Pierzina) 34. 02:17 PM - Re: First WetFly Flight (N27SB@aol.com) 35. 02:18 PM - Re: 503 losing power (Silver Fern Microlights Ltd) 36. 04:47 PM - UltraStar weight and balance (Dale Sellers) 37. 04:57 PM - Re: Fw: Rotax Price Increases (Larry Bourne) 38. 05:12 PM - Re: mo CG (Larry Bourne) 39. 05:19 PM - Re: UltraStar (Flycrazy8@aol.com) 40. 05:23 PM - Re: mo CG (Larry Bourne) 41. 05:24 PM - Re: First WetFly Flight (robert bean) 42. 05:46 PM - Re: Fw: Rotax Price Increases (John Hauck) 43. 05:49 PM - Re: First WetFly Flight (John Hauck) 44. 05:54 PM - Re: UltraStar weight and balance (John Hauck) 45. 06:23 PM - UltraStar W&B (ray anderson) 46. 06:53 PM - Re: UltraStar weight and balance (Dale Sellers) 47. 07:00 PM - Re: mo CG (Beauford) 48. 07:01 PM - Re: UltraStar W&B (Dale Sellers) 49. 07:10 PM - Re: Fair price for used 912S? (Richard Swiderwski) 50. 07:20 PM - Re: Weight and Balance (Richard Swiderwski) 51. 07:31 PM - Re: Fair price for used 912S? (Larry Bourne) 52. 09:52 PM - firestar 2 nose skid? (WADE LAWICKI) ________________________________ Message 1 _____________________________________ Time: 04:56:22 AM PST US From: "wmtatham@juno.com" Subject: Kolb-List: 503 losing power --> Kolb-List message posted by: "wmtatham@juno.com" At 09:05 AM 12/13/2004 -0800, you wrote: >--> Kolb-List message posted by: Steve Kroll > >List, > >I have a 503 single carb, points ignition with about 200 hours on >it. Recently it has started to lose power in surges. It only drops a few >hundred RPM when it does it and it comes back to full RPM but it sure gets >my attention! I rebuilt the carburator but the conditiion in the engine >still exists. Anybody got any idea what may be causing this power loss? > >Thanks, > >Steve > > >--------------------------------- > > Steve, You note triggered some old memories so Ive got another possibility for you to check out. Ive got bunches of hours on several 503s and have seen this on mine and others. Check the fuel line going into the carb. The angle of the carb fuel inlet is angled somewhat upward. As such, you need to put a loop in the line just before the inlet. That becomes the high point in your fuel delivery system. The natural inclination is to make it a big loop so there is no chance of the line getting a kink in it. However, this is a problem if you have any condition that causes bubbles to form in the fuel line such as vibration, partially clogged fuel filter, etc. These bubbles collect at the high point of the line as the engine runs. Eventually, the carb will gulp the whole bubbly mix. This briefly lowers the fuel level in the float bowl. The result (depending on how big the air slug is) ranges from a barely perceptible engine roughness to a stoppage. (yes, I have some first-hand knowledge of this.) Ive found the preventative to be minimizing the high point in the fuel line to minimize how much air can form. Get rid of any big loop of fuel line at the top. Obviously, it is also critical to make sure that you have no obstructions in the fuel supply. Even though this isnt necessarily the problem, it sure sounds familiar. I hope this helps. Best wishes, Will Tatham Juno Gift Certificates Give the gift of Internet access this holiday season. http://www.juno.com/give ________________________________ Message 2 _____________________________________ Time: 05:11:17 AM PST US From: "Rusty" <13brv3c@bellsouth.net> Subject: RE: Kolb-List: Fair price for used 912S? --> Kolb-List message posted by: "Rusty" <13brv3c@bellsouth.net> Sorry to hear about your problem. Obviously you did all the right things to get her back down & walk away grumpy & not lumpy. I had two friends who didn't. You did Good. Do not archive ----------------------- Thanks for the comments Richard. I did some things right, and some things wrong, but it worked out OK. Cheers, Rusty (wings home, fuselage home today) ________________________________ Message 3 _____________________________________ Time: 05:11:17 AM PST US From: "Rusty" <13brv3c@bellsouth.net> Subject: RE: Kolb-List: First WetFly Flight --> Kolb-List message posted by: "Rusty" <13brv3c@bellsouth.net> Well we did it, The WetFly flew today. Bryan said it was easier than on wheels. Also I did two flights today. This was my first time in a Firefly.What a great flying airplane. --------------------- Great news Steve. Neat project! Sure wish you guys would quit tempting me with these floats :-) Cheers, Rusty Do not archive ________________________________ Message 4 _____________________________________ Time: 05:51:41 AM PST US From: "PATRICK LADD" Subject: Re: Kolb-List: mo CG --> Kolb-List message posted by: "PATRICK LADD" Because of the forward pitching moment caused by the wing at cruise the tail surfaces constantly have to be pushing downward. >> Hi all, What forward pitching moment? That doesn`t look right to me. If that were so all tailplanes would be designed with an airofoil section which produced a downward component. I am sure I would have noticed. Lift is always at 90 degrees to the wing. How can it have a `forward pitching moment`? If we add weight to an a/c in front of the centre of lift we have to hold the nose up by applying back stick. Eventually, if we keep adding weight to the nose we shall run out of elevator control and dive. Similarly if we add weight aft (bigger tailwheels) we shall eventually run out of forward stick, the plane will climb, stall and ZAPP! Cheers Pat ________________________________ Message 5 _____________________________________ Time: 05:56:02 AM PST US From: "woody" Subject: Kolb-List: rotax/rotary exchange --> Kolb-List message posted by: "woody" I may be able to orchestrate a swap with a brand new (still pickled) Rotary professionally modified for aircraft use. Let me know if you are interested. > > Rusty, > > A 912S in hand versus a rotary conversion in the bush? > > That is somewhat beyond masochistic tendencies! ;-) > > You may want to seek help. ________________________________ Message 6 _____________________________________ Time: 05:56:07 AM PST US From: "woody" Subject: Re: Kolb-List: Fw: Rotax Price Increases --> Kolb-List message posted by: "woody" . I also want to beat Vamoose > into the air. I've said and done that 3 times now and am contemplating the 4th. After a while beating Lar into the air just isn't a challenge any more. I'm almost tempted to fly down there and help him get that bird into the air. ________________________________ Message 7 _____________________________________ Time: 06:15:28 AM PST US From: "Rusty" <13brv3c@bellsouth.net> Subject: RE: Kolb-List: Fw: Rotax Price Increases --> Kolb-List message posted by: "Rusty" <13brv3c@bellsouth.net> I've said and done that 3 times now and am contemplating the 4th. After a while beating Lar into the air just isn't a challenge any more. I'm almost tempted to fly down there and help him get that bird into the air. ----------------- (RD) Man, you guys are brutal. All he really needs is a new manual to replace the yellowed, crumbling pages of his original :-) Rusty (hey, it's fun to pick on Lar ) Do not archive (for Lar's sake) ________________________________ Message 8 _____________________________________ Time: 06:31:41 AM PST US From: "Larry Bourne" Subject: Re: Kolb-List: Fw: Rotax Price Increases --> Kolb-List message posted by: "Larry Bourne" Think I'm gonna re-name myself Larry Dangerfield...........or maybe Nixon. :-) Picked-On Lar. Do not Archive. Larry Bourne Palm Springs, CA Building Kolb Mk III N78LB Vamoose www.gogittum.com ----- Original Message ----- From: "woody" Subject: Re: Kolb-List: Fw: Rotax Price Increases > --> Kolb-List message posted by: "woody" > > . I also want to beat Vamoose >> into the air. > > I've said and done that 3 times now and am contemplating the 4th. After > a > while beating Lar into the air just isn't a challenge any more. I'm almost > tempted to fly down there and help him get that bird into the air. > > > ________________________________ Message 9 _____________________________________ Time: 06:32:35 AM PST US From: robert bean Subject: Re: Kolb-List: mo CG --> Kolb-List message posted by: robert bean Pat, that is why canard aircraft are more efficient...all surfaces are lifting during flight. Several current tail-type planes indeed use inverted tail planes. check out: http://www.zenithair.com/stolch701/7-design-tail.html I'm not attempting to win a right/wrong contest here. -BB do not archive On 14, Dec 2004, at 8:51 AM, PATRICK LADD wrote: > --> Kolb-List message posted by: "PATRICK LADD" > > > Because of the forward pitching moment caused by the wing at cruise > the tail > surfaces constantly have to be pushing > downward. >> > > Hi all, > What forward pitching moment? That doesn`t look right to me. If that > were so > all tailplanes would be designed with an airofoil section which > produced a > downward component. I am sure I would have noticed. > Lift is always at 90 degrees to the wing. How can it have a `forward > pitching moment`? > > If we add weight to an a/c in front of the centre of lift we have to > hold > the nose up by applying back stick. Eventually, if we keep adding > weight to > the nose we shall run out of elevator control and dive. Similarly if > we add > weight aft (bigger tailwheels) we shall eventually run out of forward > stick, > the plane will climb, stall and ZAPP! > > Cheers > > Pat > > ________________________________ Message 10 ____________________________________ Time: 06:32:59 AM PST US From: "Denny Rowe" Subject: Re: Kolb-List: mo CG --> Kolb-List message posted by: "Denny Rowe" ----- Original Message ----- From: "PATRICK LADD wrote: Because of the forward pitching moment caused by the wing at cruise the tail > surfaces constantly have to be pushing > downward. >> > > Hi all, > What forward pitching moment? That doesn`t look right to me. If that were > so > all tailplanes would be designed with an airofoil section which produced a > downward component. I am sure I would have noticed. > Lift is always at 90 degrees to the wing. How can it have a `forward > pitching moment`? Patrick and others, The center of gravity in all stable conventional aircraft is in front of the wing so there is always a forward pitching moment that the tail must overcome. Also since the wing is an incline plane presented to the relative wind, (positive angle of attack) the wind is always trying to pitch the wing forward (down), this pitching moment is added to the center of gravitys relation to the center of lift. Look at the angle of all horizontal stabs in relation to the wing, they produce downward lift, airfoil shaped or not. When the aircraft slows, this downward component is reduced, letting the tail rise and the nose drop, maintaining your trimmed airspeed. I hope this helps. Denny Rowe, Mk-3, PA ________________________________ Message 11 ____________________________________ Time: 06:35:12 AM PST US From: snuffy@usol.com Subject: RE: Kolb-List: Weight and Balance --> Kolb-List message posted by: snuffy@usol.com " Regarding the aft cg limit, Homer himself told me the Kolb wing defies convention, " Wonder what he meant by "Defies convention"? One of the great things about a Kolb is that it's so easy to move the CG in either direction. Do not archive ________________________________ Message 12 ____________________________________ Time: 06:36:44 AM PST US From: "Larry Bourne" Subject: Re: Kolb-List: mo CG --> Kolb-List message posted by: "Larry Bourne" Hi Patrick: I'm not sure about the "pitching moment" either, but it's well known that the tailplanes deliver a downward thrust to offset the nose heavy tendency of all planes. (that I've ever heard of) Therefore they ARE built with a downward airfoil, except in planes like the Kolb that angle a flat surface downward to give the same effect. Lar. Larry Bourne Palm Springs, CA Building Kolb Mk III N78LB Vamoose www.gogittum.com ----- Original Message ----- From: "PATRICK LADD" Subject: Re: Kolb-List: mo CG > --> Kolb-List message posted by: "PATRICK LADD" > > Because of the forward pitching moment caused by the wing at cruise the > tail > surfaces constantly have to be pushing > downward. >> > > Hi all, > What forward pitching moment? That doesn`t look right to me. If that were > so > all tailplanes would be designed with an airofoil section which produced a > downward component. I am sure I would have noticed. > Lift is always at 90 degrees to the wing. How can it have a `forward > pitching moment`? > > If we add weight to an a/c in front of the centre of lift we have to hold > the nose up by applying back stick. Eventually, if we keep adding weight > to > the nose we shall run out of elevator control and dive. Similarly if we > add > weight aft (bigger tailwheels) we shall eventually run out of forward > stick, > the plane will climb, stall and ZAPP! > > Cheers > > Pat > > > ________________________________ Message 13 ____________________________________ Time: 06:40:54 AM PST US From: "Larry Bourne" Subject: Re: Kolb-List: Fw: Rotax Price Increases --> Kolb-List message posted by: "Larry Bourne" Yah, Vamoose is just sitting there while I've been fishing and working on the boat. "Yellowed, crumbling ??" Haven't seen it in years. I did see the blueprints a while back, hiding behind the sofa, covered in dust and spider webs............. :-) Lazy Lar. Do not Archive. Larry Bourne Palm Springs, CA Building Kolb Mk III N78LB Vamoose www.gogittum.com ----- Original Message ----- From: "Rusty" <13brv3c@bellsouth.net> Subject: RE: Kolb-List: Fw: Rotax Price Increases > --> Kolb-List message posted by: "Rusty" <13brv3c@bellsouth.net> > > > I've said and done that 3 times now and am contemplating the 4th. After > a > while beating Lar into the air just isn't a challenge any more. I'm almost > tempted to fly down there and help him get that bird into the air. > ----------------- > > > (RD) Man, you guys are brutal. All he really needs is a new manual to > replace the yellowed, crumbling pages of his original :-) > > Rusty (hey, it's fun to pick on Lar ) > > Do not archive (for Lar's sake) > > > ________________________________ Message 14 ____________________________________ Time: 06:44:29 AM PST US From: snuffy@usol.com Subject: Re: Kolb-List: mo CG --> Kolb-List message posted by: snuffy@usol.com ________________________________ Message 15 ____________________________________ Time: 06:48:37 AM PST US From: "Creech, Lee (Local Govt)" Subject: RE: Kolb-List: mo CG --> Kolb-List message posted by: "Creech, Lee (Local Govt)" I think it's because the other force acting on the wing (besides lift) is drag. If you think of this as wind resistance pushing back on the leading edge, and combine this with lift pulling upward, it's not hard to visualize how the net result is a tendency of the wing to rotate forward. I think I've seen STOL airplanes that do have tailplanes with a noticeable upside-down-airfoil section. Mostly, though, they just rely on the angle-of-incidence setting to produce the necessary downforce. Lee Do not archive -----Original Message----- From: PATRICK LADD [mailto:pj.ladd@btinternet.com] Subject: Re: Kolb-List: mo CG "What forward pitching moment? That doesn`t look right to me. If that were so all tailplanes would be designed with an airofoil section which produced a downward component. I am sure I would have noticed. Lift is always at 90 degrees to the wing. How can it have a `forward pitching moment`?" advertising on the Matronics Forums. ________________________________ Message 16 ____________________________________ Time: 06:50:28 AM PST US From: "John Hauck" Subject: Re: Kolb-List: Weight and Balance --> Kolb-List message posted by: "John Hauck" | " Regarding the aft cg limit, Homer himself told me the Kolb wing | defies convention, " | | | Wonder what he meant by "Defies convention"? One of the great | things about a Kolb is that it's so easy to move the CG in either | direction. Snuffy/Gang: That's one of the things I like about my Kolb, UNCONVENTIONAL. As John W pointed out, sometimes the factory numbers don't alway work for everyone. They have never worked for any of my airplanes. However, I can guarantee you, Homer Kolb has blessed and flown every one I built except the Ultrastar. There are some things about my Kolb I can not explain. I simply accept them, and fly on............... John W: Thanks for explaining the test process of your Williamson/Kolb Kolbra. john h ________________________________ Message 17 ____________________________________ Time: 06:53:01 AM PST US From: "John Hauck" Subject: Re: Kolb-List: Fw: Rotax Price Increases --> Kolb-List message posted by: "John Hauck" working on | the boat. Lazy Lar. Larry/All: Desert fishing? Sand fish? Desert schooner? john h Looking out at the blue water of Lake Jordan shimmering under the sun as the thermometer hovers around 34F! DO NOT ARCHIVE ________________________________ Message 18 ____________________________________ Time: 07:30:05 AM PST US From: "PATRICK LADD" Subject: Kolb-List: C of G --> Kolb-List message posted by: "PATRICK LADD" Hi all, just after sending my last post I picked up the book which I am in the middle of reading. It is called `War in a Stringbag` (accent on the first syllable please) The Stringbag was the nickname for the Fairey Swordfish which was the main torpedo bomber of the Fleet Air Arm at the outbreak of war and usually operated from aircraft carriers. It was a massive 46ft span biplane with a 690hp radial engine, a crew of 3 in open cockpits and carried 4/ 250 lb bombs or an 18 inch diameter torpedo. The bit from the book which caught my eye was this ` "A Swordfish back from the desert (North Africa) was easily recognisable because tail wheels were often wrenched off in the soft sand and were replaced by an improvised skid. This entailed strengthening the tail-bay.The extra weight was compensated for BY REMOVING THE DECK ARRESTER GEAR. If the Navy took all that trouble to keep a big strong a/c like the Stringbag within C of G limits then we would certainly be advised to do the same with our little light weight butterflies. Cheers Pat pj.ladd@btinternet .com Do not archive ________________________________ Message 19 ____________________________________ Time: 07:33:36 AM PST US From: Kirby Dennis Contr MDA/AL Subject: Kolb-List: Re: Weight and Balance --> Kolb-List message posted by: Kirby Dennis Contr MDA/AL ray anderson wrote: << First, if the inspector who signed off their plane with such a deficiency, out of bounds CG, is either unqualified to be an inspector of a deliberate fraud, endangering the life of the inexperienced builder who expects him to catch deficiencies that would endanger his life. >> Ray, and Kolbers - Keep in mind, the FAA inspectors will not actually verify your weight and balance when they do your final airworthiness inspection. They will only ask if you did a W&B, and possibly look at your numbers, primarily to determine that you understand the concept. The inspector expects that you "did the appropriate things" to ensure your plane falls within the manufacturer's recommended CG range. He will NOT pull out the scales and check your weights. That's the nature of Experimental Amateur-Built: Some things are entirely our responsibility for ensuring they're safe. Dennis Kirby Mark-III, New Mexico ________________________________ Message 20 ____________________________________ Time: 07:35:50 AM PST US From: "PATRICK LADD" Subject: Re: Kolb-List: Weight and Balance --> Kolb-List message posted by: "PATRICK LADD" <> Hi all, it is easy to move the C of G in any a/c. Just hang weight on the nose or the tail. The question is, will it still be capable of CONTROLLED flight. Cheers Pat Do not archive. ________________________________ Message 21 ____________________________________ Time: 07:51:33 AM PST US From: "PATRICK LADD" Subject: Re: Kolb-List: mo CG --> Kolb-List message posted by: "PATRICK LADD" <> Hi Lar, I knew you would be contributing sooner or later. What `nose heavy tendency?` The centre of gravity is established by actual weighing, not by calculations of lift/drag and if the plane was lifted into the air on the end of a pole at the C of G it should balance. The acceptable limits of the range fore and aft of that point are merely to accomodate pilots of various weights, fuel load, etc.,and these can be trimmed out. The trim of course only introduces some up/down elevator to compensate and this is not efficicient. If you have to fly fully trimmed up/down all the time then your C of G is out. None of my gliders had a tailplane which is offset from the horizontal and neither has my Challenger. Cheers Pat pj.ladd@btinternet.com Do not archive ________________________________ Message 22 ____________________________________ Time: 08:00:31 AM PST US From: William George Subject: Re: Kolb-List: Verner Mark-III Update --> Kolb-List message posted by: William George Hi Dennis, Thanks for the update. Your numbers are in line with mine. Tell us about the fuel consumption ;-) Bill George Hawaii Kolb Mk-3 Verner 1400 Powerfin On Dec 13, 2004, at 9:56 PM, Kolb-List Digest Server wrote: > I flew my Mark-III this past weekend for the first time in five > months, and > decided to post a Flight Report for your interest. After all, if > Duane the > Plane does it ... ________________________________ Message 23 ____________________________________ Time: 08:10:44 AM PST US Subject: Re: Kolb-List: Re: Weight and Balance From: jhauck@elmore.rr.com --> Kolb-List message posted by: jhauck@elmore.rr.com Use http://www.onspeed.com/?A=web2mail to transform dial up connections to near broadband speed. Reccomended by Web2Mail > The inspector expects that you > "did the appropriate things" to ensure your plane falls within the > manufacturer's recommended CG range. > Dennis Kirby Dennis/All: Mine falls within the manufacturere's recommended CG range. I am the manufacturer of my airplane. Says so on my airworthiness certificate. john h ________________________________ Message 24 ____________________________________ Time: 08:10:48 AM PST US Subject: Re: Kolb-List: C of G From: jhauck@elmore.rr.com --> Kolb-List message posted by: jhauck@elmore.rr.com -------------------------------------------------- Here is a message for you from http://web2mail.com The easy way to read and send POP email on the web -------------------------------------------------- > If the Navy took all that trouble to keep a big strong a/c like the Stringbag within C of G limits then we would certainly be advised to do the same with our little light weight butterflies. > > Cheers > > Pat Pat/Gang: I am sure my MKIII is within its CG limits, not what the factory publishes. It has been thoroughly tested over more than 2,000 hours, demonstrating no tendancies for being set up beyond safe aft cg limits (for my airplane). No, Miss P'fer is not a light weight butterfly. She is a flying piss ant. hehehe She is probably a little more forgiving than the British Fairey Swordfish, "String Bag". Take care, john h ________________________________ Message 25 ____________________________________ Time: 08:14:41 AM PST US From: snuffy@usol.com Subject: Re: Kolb-List: mo CG --> Kolb-List message posted by: snuffy@usol.com I wonder where the center of lift is on a given wing in relation to the actual center of the cord? I believe it is aft. Do not archive ________________________________ Message 26 ____________________________________ Time: 08:15:15 AM PST US From: "PATRICK LADD" Subject: Re: Kolb-List: mo CG --> Kolb-List message posted by: "PATRICK LADD" <> Hi Denny and All. Seems as though we are just approaching this from differing angles. The C of G of the a/c is the point at which it would balance on a pole. The allowable range either side of that point is where the plane is controllable when it is flying. In a sail boat ( a sail is only a wing standing on end) there is the lift produced by the sail, the centre of effort, and the point where a hull would balance when pushed sideways through the water, the centre of pressure. If those two points are close (within limits) the boat will sail easy on the tiller. If they are far apart she will be hard on the rudder and will get stuck in stays every time she changes tack and become uncontrollable. Just the same for an aircraft. If the balance of the FLYING forces are far from the actual balance point she will be a dog. Cheers Pat (what the hell do I know. I fly a Challenger) Ladd ________________________________ Message 27 ____________________________________ Time: 08:17:01 AM PST US Subject: Re: Re: Kolb-List: mo CG From: jhauck@elmore.rr.com --> Kolb-List message posted by: jhauck@elmore.rr.com Use http://www.onspeed.com/?A=web2mail to transform dial up connections to near broadband speed. Reccomended by Web2Mail > If you have to fly fully trimmed > up/down all the time then your C of G is out. > > None of my gliders had a tailplane which is offset from the horizontal and > neither has my Challenger. > > Cheers > > Pat Pat/All: We are not flying gliders. You will find that the Kolb aircraft, especially the MKIII, will require a lot of nose up trim. Not because of a forward cg problem, rather the high thrustline of a pusher prop. Getting me confused now. I have aft cg and require nose up trim to fly. ;-) Take care, john h ________________________________ Message 28 ____________________________________ Time: 08:19:32 AM PST US From: Richard Pike Subject: RE: Kolb-List: mo CG --> Kolb-List message posted by: Richard Pike The lift applied by the wing is not symmetrical with respect to the surface area of the wing. When you look at a cross section of an airfoil showing the distribution of lift, the front fourth generates very little lift, and the rear two thirds (roughly) most of the lift. And depending on how the back fourth of the airfoil is shaped, you can have big changes in the pitching moment of the wing. If you look at airfoils used for flying wings, they generally have a lot of reflex in the back end of the airfoil to act like a "mini-elevator" to control the angle of attack of the wing, counteract the rotation of the lifting moment around the cg, and prevent pitch over. But the trade off is that flying wing airfoils are less efficient than "standard" airfoils. And it is true that the further toward the rear of the cg envelope you operate, the less drag you get from needing to apply up elevator to trim the airplane, (holding the nose up) something to think about when planning a fuel efficient cross country. It is also true that some airplanes are flyable with the cg aft of the acceptable envelope. That doesn't mean it's a good idea. I recently got into RC model flying in a small way, and did a little experimenting with my Tiger Moth. Moving the cg aft in small stages continuously improves the agility of the airplane, but if I go a tad too far, I have to hope it impacts in the tall grass, because I can no longer fly it, the pitch excursions come faster than I can catch them. I would hate to have to have to try that in something I was sitting in. A number of years ago, a friend was selling a Maxair Hummer, and the friend was in the 210 pound range. A potential buyer came to look at it, and was interested, and being a long time pilot with experience in Cubs, Skyhawks, etc, was briefed on how to fly it, and away he went. Unfortunately, he only weighed about 150 pounds, and nobody thought to consider the difference in pilot weights. (Doh) He had a fight on his hands, the aircraft was pitch unstable. He had to slip the shoulder harness off and lean forward over the stick as far as he could go to get it to settle down enough to get around the pattern and land. (No sale...) IMHO, an airplane in the aft end of it's cg range flies best. An airplane aft of it's cg range flies ???? Know where yours is, and find out carefully. Richard Pike MKIII N420P (420ldPoops) At 09:48 AM 12/14/2004 -0500, you wrote: >--> Kolb-List message posted by: "Creech, Lee (Local Govt)" > > >I think it's because the other force acting on the wing (besides lift) is >drag. If you think of this as wind resistance pushing back on the leading >edge, and combine this with lift pulling upward, it's not hard to visualize >how the net result is a tendency of the wing to rotate forward. > >I think I've seen STOL airplanes that do have tailplanes with a noticeable >upside-down-airfoil section. Mostly, though, they just rely on the >angle-of-incidence setting to produce the necessary downforce. > >Lee >Do not archive > >-----Original Message----- >From: PATRICK LADD [mailto:pj.ladd@btinternet.com] >To: kolb-list@matronics.com >Subject: Re: Kolb-List: mo CG > >"What forward pitching moment? That doesn`t look right to me. If that were >so >all tailplanes would be designed with an airofoil section which produced a >downward component. I am sure I would have noticed. >Lift is always at 90 degrees to the wing. How can it have a `forward >pitching moment`?" > > >advertising on the Matronics Forums. > > ________________________________ Message 29 ____________________________________ Time: 08:55:36 AM PST US From: "David Paule" Subject: Kolb-List: Re: Tail Heavy Firestar --> Kolb-List message posted by: "David Paule" I have two sets of plans with my FSII. I bought the plane, built, last year, and it came with a set of plans. Several years ago, I bought a set of plans just to see what it all looked like. The set that came with the plane (marked Rev 0, 1993) gives these CG limits: 20% to 37%, based on a chord of 64". That works out to 12.8" to 23.68" aft of the leading edge. A slightly newer set of plans (this set is marked 1996, no rev) that I got from the Old Kolb factory gives these CG limits: 20% to 35%, based on a 61" chord. And that works out to 12.2" to 21.35" aft of the leading edge. I measured the wings carefully and the actual Mean Aerodynamic Chord is 58.00 inches, located 81.76" outboard of the rear spar pivot. This is based on extending the aileron gap seal to the root, which I haven't yet done. It migh tbe worth mentioning that the actual MAC is only a matter of academic interest. What matters is where the CG is. That's why I worked it out for both sets of plans. The wings are the same between both sets of plans, by the way. It appears as if the Old Kolb factory decided that there's enough elevator authority to justify moving the forward limit forward by 0.6", and that they felt safer if the aft CG limit were also moved forward by 2.33". That indicates that there is some concern, we don't know what it actually is, for the aft CG limit. My CG is nominally pretty far aft, and I don't weight as much as some of the bigger gentlemen on this forum. Accordingly, I added about 42 pounds of ballast under the seat cushion to fly the plane, and it flies fine. The CG was about an inch forward of the aft limit of 21.35", which I used. Over the winter, I'm planning on sweeping the wings back 3.5 degrees and removing the ballast. I'd originally only planned on 2 degrees, but then I bought a full-swiveling tailwheel.... The wing sweep-back, if done in moderation, can have the effect of moving the CG forward. There are a few anticipated side effects, the most important being an increase in adverse yaw. A minor secondary side effect is that the critical Mach number will be raised slightly, if that matters to you. It doesn't to me. Dave Paule Boulder, CO ________________________________ Message 30 ____________________________________ Time: 09:32:50 AM PST US DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; b=oT+DUNj1jid0QhViKTIIkPVa+TxvxFxyjVrxpXTO4ccKgf6I3hvbcImP/esYBIqTjFIWHoM0dBlOKJzaLh2xKe35yKLIVknqtId7UGuBRUXZKm/iOIl2gHDESagBZN7GpGblfL56sq/yzdTTJcx7O7xhXrJnqQ9/ybM+Cpu/TMU= ; From: ray anderson Subject: Re: Kolb-List: mo CG --> Kolb-List message posted by: ray anderson --> Kolb-List message posted by: "PATRICK LADD" <> Hi Lar, "I knew you would be contributing sooner or later.What `nose heavy tendency?` The centre of gravity is established by actual weighing, not by calculations of lift/drag and if the plane was lifted into the air on the end of a pole at the C of G it should balance." I can't speak about any Kolb except the UltraStar and here's what Homer said in the builders manual for it. " The Ultra Star should balance with the pilot in the seat at the 25% to 30% chord position. 16" to 19" from the leading edge of the wing. The centerline of the 1" square tube that the wings attach to is 18" from the leading edge. To check the balance hang the UltraStar from a point within this 3" range, and with the pilot sitting in the seat, the plane should balance. The fuselage tube will be at a 10 to 12 degree angle ( tail lower than front) when the plane is considered balanced. In any case you never want to have a tail heavy condition, this is where the balance point would be further rearward than 19". A tail heavy condition is dangerous and must be avoided". Words from the master builder. Most of we UltraStar builders removed the tanks from the position under our legs and replaced with a larger tank behind us, in the cage. In my case, an 8 gal. fiberglass tank. Immediately, I was out of C.G. I also placed a large strobe back in the tail area. Since I was licensing it as experimental, I brought it back within Homers specs by constructing a fairly large fiberglass enclosure and windshield up front. Flew beautifully. Since someone mentioned the different characteristics of a canard plane, I'll comment that the only canard type I've ever built and flown was Burt Rutan's little all composite "Quickie". It had a very narrow C.G.range and you had better be sure it was within that. It was extremely sensitive pitch wise and could have been awfully dangerous if any outside the design range. However, where can you find another homebuilt that will cruise at 116 - 118 mph with 21-22 HP, burning 1-1/2 gals of auto fuel (any kind). Loved it. If any are interested, I've posted pictures of both at http://www.matronics.com/photoshare May be a couple of days before they are posted. Do not archive --------------------------------- ________________________________ Message 31 ____________________________________ Time: 11:55:05 AM PST US From: "David Paule" Subject: Kolb-List: Re: Tail Heavy Firestar --> Kolb-List message posted by: "David Paule" Apparently there's some confusion as to a couple points I made. I regret that. 1. The Mean Aerodynamic Chord is the effective chord of the wing as a whole. It includes the ailerons, the tip radius and the rest of the geometry. As such, it's smaller than the wing's maximum chord, which is at the aileron, inboard of the tip radius and outboard of the aileron taper. This MAC is a theoretical chord and isn't necessarily the chord you use to determine the CG position - that chord is defined by Kolb. 2. When you calculate the CG for your airplane, you must, repeat MUST use the chord and center of gravity limits given in your plans. The plane might be unsafe for one reason or another if you fly outside those limits. If you plan set says to use a chord of 61" or 64", then you must use that to calculate the CG. I hope that this clear up the matter. David Paule Boulder, CO > I have two sets of plans with my FSII. I bought the plane, built, last year, > and it came with a set of plans. Several years ago, I bought a set of plans > just to see what it all looked like. > > The set that came with the plane (marked Rev 0, 1993) gives these CG limits: > 20% to 37%, based on a chord of 64". That works out to 12.8" to 23.68" aft > of the leading edge. > > A slightly newer set of plans (this set is marked 1996, no rev) that I got > from the Old Kolb factory gives these CG limits: 20% to 35%, based on a 61" > chord. And that works out to 12.2" to 21.35" aft of the leading edge. > > I measured the wings carefully and the actual Mean Aerodynamic Chord is > 58.00 inches, located 81.76" outboard of the rear spar pivot. This is based > on extending the aileron gap seal to the root, which I haven't yet done. It > migh tbe worth mentioning that the actual MAC is only a matter of academic > interest. What matters is where the CG is. That's why I worked it out for > both sets of plans. The wings are the same between both sets of plans, by > the way. > > It appears as if the Old Kolb factory decided that there's enough elevator > authority to justify moving the forward limit forward by 0.6", and that they > felt safer if the aft CG limit were also moved forward by 2.33". That > indicates that there is some concern, we don't know what it actually is, for > the aft CG limit. ________________________________ Message 32 ____________________________________ Time: 01:58:17 PM PST US From: N27SB@aol.com Subject: Re: Kolb-List: First WetFly Flight --> Kolb-List message posted by: N27SB@aol.com In a message dated 12/14/2004 8:12:43 AM Eastern Standard Time, 13brv3c@bellsouth.net writes: << Great news Steve. Neat project! Sure wish you guys would quit tempting me with these floats :-) Cheers, Rusty >> Sorry, but when Bryan says that this is the most fun he has had in a kolb in years I guess we should share. Steve WetFly #007 do not archive ________________________________ Message 33 ____________________________________ Time: 02:17:51 PM PST US From: "Mike Pierzina" Subject: Kolb-List: Aero Engineer --> Kolb-List message posted by: "Mike Pierzina" Hey Guys, What happen to Chris"topher" ?? He use to jump in and "BLIND" me with tech talk like you guys are discusing... I've been reading the book "Stick and Rudder"... I can read it and understand it, But can't SPEAK IT... Do Not Archive Gotta Fly... Mike in MN ...Brrrrr My Web Site: http://www.geocities.com/planecrazzzy/Planecrazzzy.html Sometimes you just have to take the leap and build your wings on the way down... Gotta Fly... -- ________________________________ Message 34 ____________________________________ Time: 02:17:51 PM PST US From: N27SB@aol.com Subject: Re: Kolb-List: First WetFly Flight --> Kolb-List message posted by: N27SB@aol.com Hello to all, I just thought of something of possible interest in regard to WetFly#007. Duane built it per the plans including the 15" ailerons. WE thought about trimming them down to the now popular short lengths. Since Duane had flown it quite a bit and was happy with it so we flew it as is. WE flew in a steady 20 mph wind with some bumps. Bryan was pleased with roll response and liked the extra lift for a float plane. I had never flown a Firefly but found the controls to feel well balanced. It looks like we are going to keep em. Steve Boetto ` #007 ________________________________ Message 35 ____________________________________ Time: 02:18:41 PM PST US From: "Silver Fern Microlights Ltd" Subject: Re: Kolb-List: 503 losing power --> Kolb-List message posted by: "Silver Fern Microlights Ltd" Steve, could be that the float level is too low if it is happening at high power settings. Kiwi ----- Original Message ----- From: Subject: Kolb-List: 503 losing power > --> Kolb-List message posted by: "wmtatham@juno.com" > > > At 09:05 AM 12/13/2004 -0800, you wrote: > >>--> Kolb-List message posted by: Steve Kroll >> >>List, >> >>I have a 503 single carb, points ignition with about 200 hours on >>it. Recently it has started to lose power in surges. It only drops a few >>hundred RPM when it does it and it comes back to full RPM but it sure gets >>my attention! I rebuilt the carburator but the conditiion in the engine >>still exists. Anybody got any idea what may be causing this power loss? >> >>Thanks, >> >>Steve >> >> >>--------------------------------- >> >> > Steve, > > You note triggered some old memories so Ive got another possibility for > you to check out. Ive got bunches of hours on several 503s and have seen > this on mine and others. Check the fuel line going into the carb. > > The angle of the carb fuel inlet is angled somewhat upward. As such, you > need to put a loop in the line just before the inlet. That becomes the > high point in your fuel delivery system. The natural inclination is to > make it a big loop so there is no chance of the line getting a kink in it. > However, this is a problem if you have any condition that causes bubbles > to form in the fuel line such as vibration, partially clogged fuel filter, > etc. These bubbles collect at the high point of the line as the engine > runs. Eventually, the carb will gulp the whole bubbly mix. This > briefly lowers the fuel level in the float bowl. The result (depending > on how big the air slug is) ranges from a barely perceptible engine > roughness to a stoppage. (yes, I have some first-hand knowledge of > this.) > > Ive found the preventative to be minimizing the high point in the fuel > line to minimize how much air can form. Get rid of any big loop of fuel > line at the top. Obviously, it is also critical to make sure that you > have no obstructions in the fuel supply. Even though this isnt > necessarily the problem, it sure sounds familiar. I hope this helps. > > Best wishes, > > Will Tatham > > > Juno Gift Certificates > Give the gift of Internet access this holiday season. > http://www.juno.com/give > > > ________________________________ Message 36 ____________________________________ Time: 04:47:12 PM PST US From: "Dale Sellers" Subject: Kolb-List: UltraStar weight and balance --> Kolb-List message posted by: "Dale Sellers" While you guys are on the subject of weight and balance, I have a question. I don't have any techical info on my US so I don't know how to do a weight and balance on it. I have about 10 hours on it now and have wiped out one set of gear on a paved runway and bent another. Unless I fly it on at a pretty high speed, I've found that I can't get the nose up on flair. I suspect a nose heavy problem. Someone told me once to lift the plane by the main spar attach point but I don't have a way to lift it and if I did, I don't know what the angle of the boom should be. Anybody know hou to do a true weight and balance on a US? Dale Sellers Georgia UltraStar ________________________________ Message 37 ____________________________________ Time: 04:57:34 PM PST US From: "Larry Bourne" Subject: Re: Kolb-List: Fw: Rotax Price Increases --> Kolb-List message posted by: "Larry Bourne" Yah, and you guys should see the idyllic spot John is fortunate enuf to live in. Right on the edge of the lake. Beautiful. Envious Desert Rat Lar. Do not Archive. Larry Bourne Palm Springs, CA Building Kolb Mk III N78LB Vamoose www.gogittum.com ----- Original Message ----- From: "John Hauck" Subject: Re: Kolb-List: Fw: Rotax Price Increases > --> Kolb-List message posted by: "John Hauck" > > working on > > Larry/All: > > Desert fishing? Sand fish? Desert schooner? > > john h Looking out at the blue water of Lake Jordan shimmering under > the sun as the thermometer hovers around 34F! > > DO NOT ARCHIVE > > > ________________________________ Message 38 ____________________________________ Time: 05:12:42 PM PST US From: "Larry Bourne" Subject: Re: Kolb-List: mo CG --> Kolb-List message posted by: "Larry Bourne" Well sir, we're getting onto slightly shaky ground here, but I hafta respectfully disagree with some of that. "As I understand it" - if you hang a plane by a string at the center of balance, it should indeed balance, but that's not entirely how we fly them. The cg range is calculated so that the plane will have sufficient elevator to flare while landing at low speed while at max forward cg, and be able to fly (fall ??) out of a stall at full aft cg, so as not to enter a flat spin. In the case of the Kolb and the Challenger, if you check closely, I do believe you'll find that in flight position, the tailplane is angled a couple of degrees downward. In the Cessnas, it's an upside down airfoil. Flame away. You a perty sneaky feller, eh ?? I've owed you a message for a long time now, and good intentions don't count. Road to hell is paved with 'em, they say. This was a good way to rattle my cage a bit. I've had some issues recently, but I think I'm out of the woods now, and getting caught back up. I've been pretty quiet on the List, too, but I've still enjoyed reading the messages. Keep up your participation on the List..........it makes for enjoyable reading. I like your writing style and your sense of humor, as well as your level of knowledge. Lar. Larry Bourne Palm Springs, CA Building Kolb Mk III N78LB Vamoose www.gogittum.com ----- Original Message ----- From: "PATRICK LADD" Subject: Re: Kolb-List: mo CG > --> Kolb-List message posted by: "PATRICK LADD" > > < heavy tendency of all planes.>> > > Hi Lar, > I knew you would be contributing sooner or later. > What `nose heavy tendency?` > The centre of gravity is established by actual weighing, not by > calculations > of lift/drag and if the plane was lifted into the air on the end of a pole > at the C of G it should balance. > The acceptable limits of the range fore and aft of that point are merely > to > accomodate pilots of various weights, fuel load, etc.,and these can be > trimmed out. The trim of course only introduces some up/down elevator to > compensate and this is not efficicient. If you have to fly fully trimmed > up/down all the time then your C of G is out. > > None of my gliders had a tailplane which is offset from the horizontal and > neither has my Challenger. > > Cheers > > Pat > pj.ladd@btinternet.com > > Do not archive > > > ________________________________ Message 39 ____________________________________ Time: 05:19:49 PM PST US From: Flycrazy8@aol.com Subject: Re: Kolb-List: UltraStar --> Kolb-List message posted by: Flycrazy8@aol.com Hey Dale The best way I've found to land a Kolb is to fly it to the ground, level off a foot above ground, then back off the power. There is not any excess energy to bleed off as in a general aviation aircraft so therefore no reason to "flair". Bat Bax ________________________________ Message 40 ____________________________________ Time: 05:23:35 PM PST US From: "Larry Bourne" Subject: Re: Kolb-List: mo CG --> Kolb-List message posted by: "Larry Bourne" Here we go again. Thought I was replying direct to Pat. Sorry group. Lar. Do not Archive. Larry Bourne Palm Springs, CA Building Kolb Mk III N78LB Vamoose www.gogittum.com ----- Original Message ----- From: "Larry Bourne" Subject: Re: Kolb-List: mo CG > --> Kolb-List message posted by: "Larry Bourne" > > Well sir, we're getting onto slightly shaky ground here, but I hafta > respectfully disagree with some of that. "As I understand it" - if you > hang > a plane by a string at the center of balance, it should indeed balance, > but > that's not entirely how we fly them. The cg range is calculated so that > the > plane will have sufficient elevator to flare while landing at low speed > while at max forward cg, and be able to fly (fall ??) out of a stall at > full > aft cg, so as not to enter a flat spin. In the case of the Kolb and the > Challenger, if you check closely, I do believe you'll find that in flight > position, the tailplane is angled a couple of degrees downward. In the > Cessnas, it's an upside down airfoil. Flame away. > > You a perty sneaky feller, eh ?? I've owed you a message for a long time > now, and good intentions don't count. Road to hell is paved with 'em, > they > say. This was a good way to rattle my cage a bit. I've had some > issues > recently, but I think I'm out of the woods now, and getting caught back > up. > I've been pretty quiet on the List, too, but I've still enjoyed reading > the > messages. Keep up your participation on the List..........it makes > for > enjoyable reading. I like your writing style and your sense of humor, as > well as your level of knowledge. Lar. > > Larry Bourne > Palm Springs, CA > Building Kolb Mk III > N78LB Vamoose > www.gogittum.com > > ----- Original Message ----- > From: "PATRICK LADD" > To: > Subject: Re: Kolb-List: mo CG > > >> --> Kolb-List message posted by: "PATRICK LADD" >> >> <> heavy tendency of all planes.>> >> >> Hi Lar, >> I knew you would be contributing sooner or later. >> What `nose heavy tendency?` >> The centre of gravity is established by actual weighing, not by >> calculations >> of lift/drag and if the plane was lifted into the air on the end of a >> pole >> at the C of G it should balance. >> The acceptable limits of the range fore and aft of that point are merely >> to >> accomodate pilots of various weights, fuel load, etc.,and these can be >> trimmed out. The trim of course only introduces some up/down elevator to >> compensate and this is not efficicient. If you have to fly fully trimmed >> up/down all the time then your C of G is out. >> >> None of my gliders had a tailplane which is offset from the horizontal >> and >> neither has my Challenger. >> >> Cheers >> >> Pat >> pj.ladd@btinternet.com >> >> Do not archive >> >> >> > > > ________________________________ Message 41 ____________________________________ Time: 05:24:31 PM PST US From: robert bean Subject: Re: Kolb-List: First WetFly Flight --> Kolb-List message posted by: robert bean > > > Sorry, but when Bryan says that this is the most fun he has had in a > kolb in > years I guess we should share. > > Steve > WetFly #007 > do not archive > I have fantasies of flying to any of the nearby finger lakes and swimming off the floats. A flying catamaran. Maybe someday.... -BB do not archive > > ________________________________ Message 42 ____________________________________ Time: 05:46:24 PM PST US From: "John Hauck" Subject: Re: Kolb-List: Fw: Rotax Price Increases --> Kolb-List message posted by: "John Hauck" | Yah, and you guys should see the idyllic spot John is fortunate enuf to live | in. Right on the edge of the lake. Beautiful. Envious Desert | Rat Lar. Rat Lar/Gang: Go east, young man! Go east!! john h 30F and the bottom is falling out tonight. DO NOT ARCHIVE ________________________________ Message 43 ____________________________________ Time: 05:49:31 PM PST US From: "John Hauck" Subject: Re: Kolb-List: First WetFly Flight --> Kolb-List message posted by: "John Hauck" | swimming off the | floats. A flying catamaran. Maybe someday.... -BB Bob B/Gang: Yea, after you break the ice. hehehe john h DO NOT ARCHIVE ________________________________ Message 44 ____________________________________ Time: 05:54:34 PM PST US From: "John Hauck" Subject: Re: Kolb-List: UltraStar weight and balance --> Kolb-List message posted by: "John Hauck" Dale/All: "|I don't have any techical info on my US so I don't know how to do a weight and balance on it." It has been more than twenty years since I built and test flew my Ultrastar. I didn't do a weight and balance on it. Don't think the instructions described anything but hanging it from the square tube of the main spar attachments, if you felt you needed to do a W&B before flying it. Never considered doing a W&B on the US. I can't get my hands on my Ultrastar Construction Manual right now, but I did find my 1985 edition of the Firestar Manual. Not a word in it about weight and balance, period! Not even hanging the critter by the neck to see what happens. Normally, if the Ultrastar and Firestar were built to plans, the aircraft would be well within CG limits. We didn't do them, didn't talk about them, and we flew them, back in the mid-1980's, with no CG problems. Some of us changed configurations of the aircraft to carry more fuel and cargo, with no CG problems. "I have about 10 hours on it now and have wiped out one set of gear on a paved runway and bent another. Unless I fly it on at a pretty high speed, I've found that I can't get the nose up on flair. I suspect a nose heavy problem. " You did not say what your airspeed was on approach. However, most Ultrastars built in the standard configuration, stalled at 25 mph. When I first started flying my US, I decided on 40 mph approach speed. 40 mph in an US seemed like 400 mph. Very easy to get in the classic US mush, thinking you are flying "fast", when in fact you are stalling and breaking "rigid" landing gear. Unless you have something seriously mis-rigged/mis-configured, you should have no problem flaring an US. Normally, they have no pitch control problems. There are hundreds, probably thousands of Ultrastars and Firestars out there flying that never had a weight and balance performed. Hope they do not fall out of the sky tail first. john h ________________________________ Message 45 ____________________________________ Time: 06:23:43 PM PST US DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; b=yLgnMM6I5TqjrzD0fgMEkO3oHk6iqTJ1mYkwjKCbdgKdbv6RInn23Qoblf3mGENoEp+vpSaiJzmh5IU075dzVB+EhEbWy9yKGkmGldahC0YTN6xzc8h8vF/D77xtY8fwNeTX4kPe8yxFQfZbYyWETmaoEqSDD2jez/C+Yd/7XyI= ; From: ray anderson Subject: Kolb-List: UltraStar W&B --> Kolb-List message posted by: ray anderson Dale and other UltraStar owners, I posted this yesterday. Dale, if you need more, contact me off line and I'll send you the method I used using scales under the wheels. I can't speak about any Kolb except the UltraStar and here's what Homer said in the builders manual for it. " The Ultra Star should balance with the pilot in the seat at the 25% to 30% chord position. 16" to 19" from the leading edge of the wing. The centerline of the 1" square tube that the wings attach to is 18" from the leading edge. To check the balance hang the UltraStar from a point within this 3" range, and with the pilot sitting in the seat, the plane should balance. The fuselage tube will be at a 10 to 12 degree angle ( tail lower than front) when the plane is considered balanced. In any case you never want to have a tail heavy condition, this is where the balance point would be further rearward than 19". A tail heavy condition is dangerous and must be avoided". Words from the master builder. Most of we UltraStar builders removed the tanks from the position under our legs and replaced with a larger tank behind us, in the cage. In my case, an 8 gal. fiberglass tank. Immediately, I was out of C.G. I also placed a large strobe back in the tail area. Since I was licensing it as experimental, I brought it back within Homers specs by constructing a fairly large fiberglass enclosure and windshield up front. Flew beautifully. Since someone mentioned the different characteristics of a canard plane, I'll comment that the only canard type I've ever built and flown was Burt Rutan's little all composite "Quickie". It had a very narrow C.G.range and you had better be sure it was within that. It was extremely sensitive pitch wise and could have been awfully dangerous if any outside the design range. Had a fairly hot landing speed and proper flair was important. However, where can you find another homebuilt that will cruise at 116 - 118 mph with 21-22 HP, burning 1-1/2 gals of auto fuel (any kind). Loved it. If any are interested, I've posted pictures of both at http://www.matronics.com/photoshare May be a couple of days before they are posted. Do not archive --------------------------------- ________________________________ Message 46 ____________________________________ Time: 06:53:47 PM PST US From: "Dale Sellers" Subject: Re: Kolb-List: UltraStar weight and balance --> Kolb-List message posted by: "Dale Sellers" John, I did add a nose fairing but I moved the fuel tank to the the cage behind the seat which should have compensated for the extra weight on the nose. Dale ----- Original Message ----- From: "John Hauck" Subject: Re: Kolb-List: UltraStar weight and balance > --> Kolb-List message posted by: "John Hauck" > > Dale/All: > > "|I don't have any techical info on my US so I don't know how to do a > weight and balance on it." > > It has been more than twenty years since I built and test flew my > Ultrastar. I didn't do a weight and balance on it. Don't think the > instructions described anything but hanging it from the square tube of > the main spar attachments, if you felt you needed to do a W&B before > flying it. Never considered doing a W&B on the US. > > I can't get my hands on my Ultrastar Construction Manual right now, > but I did find my 1985 edition of the Firestar Manual. Not a word in > it about weight and balance, period! Not even hanging the critter by > the neck to see what happens. > > Normally, if the Ultrastar and Firestar were built to plans, the > aircraft would be well within CG limits. We didn't do them, didn't > talk about them, and we flew them, back in the mid-1980's, with no CG > problems. Some of us changed configurations of the aircraft to carry > more fuel and cargo, with no CG problems. > > "I have about 10 hours on it now and have wiped out one set of gear on > a paved runway and bent another. Unless I fly it on at a pretty high > speed, I've found that I can't get the nose up on flair. I suspect a > nose heavy problem. " > > You did not say what your airspeed was on approach. However, most > Ultrastars built in the standard configuration, stalled at 25 mph. > When I first started flying my US, I decided on 40 mph approach speed. > 40 mph in an US seemed like 400 mph. Very easy to get in the classic > US mush, thinking you are flying "fast", when in fact you are stalling > and breaking "rigid" landing gear. > > Unless you have something seriously mis-rigged/mis-configured, you > should have no problem flaring an US. Normally, they have no pitch > control problems. > > There are hundreds, probably thousands of Ultrastars and Firestars out > there flying that never had a weight and balance performed. Hope they > do not fall out of the sky tail first. > > john h > > > ________________________________ Message 47 ____________________________________ Time: 07:00:23 PM PST US From: "Beauford" Subject: Re: Kolb-List: mo CG --> Kolb-List message posted by: "Beauford" Ray... Outrage, Sir...! I must take exception to your jocular reference to Lar's reference to "nose heavy tendencies..." I feel your petty personal attack on a seasoned Kolb builder of Lar's reputation to be totally unwarranted, Sir..... Just because Lar is currently best known as the premier constructor of Kolb non-flying southwestern-motif lawn and porch furniture for the past half-decade, does not give you, good sir, license to take cheap shots at my close personal friend.... He's certainly doing the best he can under the outrageously difficult circumstances he has been forced to cope with over the past two...er three... well, mebbe four years..... and I, for one, have a child-like faith that whatever the hell that thing is he is building / has built on his front porch will eventually shake off the years of accumulated desert pigeon crap and mount to the skies as on the wings of eagles... well, mebbe starlings.... or whatever..... Anyway.... I'm absolutely sure he has, at a minimum, read a book somewheres about flying Kolbs.... and he is, therefore, deserving of your full respect when opining about how is is that Kolbs might actually come to fly, taxi real fast, or sit stationary on a dusty front porch .....in a nose-heavy condition. So there....! Beauford FF#076 Do not archive ----- Original Message ----- From: "ray anderson" > Hi Lar, > "I knew you would be contributing sooner or later.What `nose heavy > tendency?` > > > --------------------------------- > > > ________________________________ Message 48 ____________________________________ Time: 07:01:39 PM PST US From: "Dale Sellers" Subject: Re: Kolb-List: UltraStar W&B --> Kolb-List message posted by: "Dale Sellers" Thanks for the info Ray. I, too, added a nose fairing and moved the fuel tank to up behind my head in the cage. It's probably O.K. but it's too cold to fly and I thought I'd check it by the specs until it warms up a little. Give me something to do. Its supposed to be 21 degrees here in south Georgia tonight. Unusual for us here. Dale Sellers Georgia UltraStar ----- Original Message ----- From: "ray anderson" Subject: Kolb-List: UltraStar W&B > --> Kolb-List message posted by: ray anderson > > Dale and other UltraStar owners, > I posted this yesterday. Dale, if you need more, contact me off line and > I'll send you the method I used using scales under the wheels. > I can't speak about any Kolb except the UltraStar and here's what > Homer said in the builders manual for it. > > " The Ultra Star should balance with the pilot in the seat at the > 25% to 30% chord position. 16" to 19" from the leading edge of the wing. > The centerline of the 1" square tube that the wings attach to is 18" > from the leading edge. To check the balance hang the UltraStar from a > point within this 3" range, and with the pilot sitting in the seat, the > plane should balance. The fuselage tube will be at a 10 to 12 degree > angle ( tail lower than front) when the plane is considered balanced. > In any case you never want to have a tail heavy condition, this is > where the balance point would be further rearward than 19". A tail > heavy condition is dangerous and must be avoided". > > Words from the master builder. > Most of we UltraStar builders removed the tanks from the position > under our legs and replaced with a larger tank behind us, in the cage. > In my case, an 8 gal. fiberglass tank. Immediately, I was out of C.G. I > also placed a large strobe back in the tail area. Since I was > licensing it as experimental, I brought it back within Homers specs by > constructing a fairly large fiberglass enclosure and windshield up front. > Flew > beautifully. > Since someone mentioned the different characteristics of a canard > plane, I'll comment that the only canard type I've ever built and flown > was Burt Rutan's little all composite "Quickie". It had a very narrow > C.G.range and you had better be sure it was within that. It was > extremely sensitive pitch wise and could have been awfully dangerous if > any > outside the design range. Had a fairly hot landing speed and proper flair > was important. However, where can you find another homebuilt > that will cruise at 116 - 118 mph with 21-22 HP, burning 1-1/2 gals of > auto fuel (any kind). Loved it. > If any are interested, I've posted pictures of both at > http://www.matronics.com/photoshare > May be a couple of days before they are posted. > > Do not archive > > > --------------------------------- > > > ________________________________ Message 49 ____________________________________ Time: 07:10:57 PM PST US From: "Richard Swiderwski" Subject: RE: Kolb-List: Fair price for used 912S? --> Kolb-List message posted by: "Richard Swiderwski" Lar, Sounds good to me... except for the back seat, a fuel tank beat you to it. Richard S Do not archive -----Original Message----- From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of Larry Bourne Subject: Re: Kolb-List: Fair price for used 912S? --> Kolb-List message posted by: "Larry Bourne" As much as I enjoyed the visit last summer, that sure won't be a hardship. Besides, we still hafta make the boat ride to Silver Springs. I just bought a little bigger and faster boat, with more room for all, so I'll look forward to it. But...........you'll hafta put the back seat back in the SS so I can go for a ride. :-) Lar. Do not Archive. Larry Bourne Palm Springs, CA Building Kolb Mk III N78LB Vamoose www.gogittum.com ----- Original Message ----- From: "Richard Swiderwski" Subject: RE: Kolb-List: Fair price for used 912S? > --> Kolb-List message posted by: "Richard Swiderwski" > > > Hey Lar, > > Summer was a long time ago. I reckon we'll have to do it again! > > Do not archive > > > ......Dog-gone it, I thought we'd made friends last summer.........?? Am > I > gonna > hafta come back there and start all over next summer ?? Vamoose ?? Next > weekend.........promise. :-) Lyin' Lar. > Do > not Archive. > ________________________________ Message 50 ____________________________________ Time: 07:20:42 PM PST US From: "Richard Swiderwski" Subject: RE: Kolb-List: Weight and Balance --> Kolb-List message posted by: "Richard Swiderwski" Snuffy, Well I'm not certain, but the way I understood it was that our rear cg limit is more than most, that it doesn't fit the standard profile. Richard Swiderski -----Original Message----- From: owner-kolb-list-server@matronics.com [mailto:owner-kolb-list-server@matronics.com] On Behalf Of snuffy@usol.com Subject: RE: Kolb-List: Weight and Balance --> Kolb-List message posted by: snuffy@usol.com " Regarding the aft cg limit, Homer himself told me the Kolb wing defies convention, " Wonder what he meant by "Defies convention"? One of the great things about a Kolb is that it's so easy to move the CG in either direction. Do not archive ________________________________ Message 51 ____________________________________ Time: 07:31:55 PM PST US From: "Larry Bourne" Subject: Re: Kolb-List: Fair price for used 912S? --> Kolb-List message posted by: "Larry Bourne" I'll hold it in my lap. :-) Do not Archive. Larry Bourne Palm Springs, CA Building Kolb Mk III N78LB Vamoose www.gogittum.com ----- Original Message ----- From: "Richard Swiderwski" Subject: RE: Kolb-List: Fair price for used 912S? > --> Kolb-List message posted by: "Richard Swiderwski" > > > Lar, > Sounds good to me... except for the back seat, a fuel tank beat you > to it. Richard S > > Do not archive > > -----Original Message----- > From: owner-kolb-list-server@matronics.com > [mailto:owner-kolb-list-server@matronics.com] On Behalf Of Larry Bourne > To: kolb-list@matronics.com > Subject: Re: Kolb-List: Fair price for used 912S? > > --> Kolb-List message posted by: "Larry Bourne" > > As much as I enjoyed the visit last summer, that sure won't be a hardship. > Besides, we still hafta make the boat ride to Silver Springs. I just > bought > > a little bigger and faster boat, with more room for all, so I'll look > forward to it. But...........you'll hafta put the back seat back in the > SS > so I can go for a ride. :-) Lar. Do > not Archive. > > Larry Bourne ________________________________ Message 52 ____________________________________ Time: 09:52:18 PM PST US From: WADE LAWICKI Subject: Kolb-List: firestar 2 nose skid? --> Kolb-List message posted by: WADE LAWICKI looking for pics or instructions for adding a nose skid to a 93 fs2. my plans dont show one but ive saw pics of fs2 with them. nose weight will only help and i think the skid might come in handy through my transition to a tail dragger. thanks. wade lawicki fs2 1030 ---------------------------------