---------------------------------------------------------- Kolb-List Digest Archive --- Total Messages Posted Tue 03/28/06: 30 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:01 AM - Re: a stall between 2 fools (pat ladd) 2. 05:48 AM - Re: Re: Land Shorter VG's on Firestar II (pat ladd) 3. 06:40 AM - Re: Land Shorter VG's on Firestar II (John Jung) 4. 06:54 AM - Re: Land Shorter VG's on Firestar II (John Jung) 5. 06:55 AM - Re: Re: Land Shorter VG's on Firestar II (Richard Pike) 6. 07:27 AM - Re: Re: Land Shorter VG's on Firestar II- reply from Joa (John Hauck) 7. 07:59 AM - Re: a stall between 2 fools (Ed Chmielewski) 8. 08:02 AM - center of lift (boyd) 9. 08:03 AM - Re: Turbulent airfoils and barns (Herb Gayheart) 10. 08:37 AM - Re: a stall between 2 fools (pat ladd) 11. 12:16 PM - Re: Re: Land Shorter VG's on Firestar II (Jeremy Casey) 12. 12:21 PM - Re: center of lift (Jeremy Casey) 13. 12:25 PM - Re: a stall between 2 fools (Jeremy Casey) 14. 12:37 PM - Re: Re: Land Shorter VG's on Firestar II- reply from Joa (Larry Cottrell) 15. 02:43 PM - Re: Re: 4th Annual Sun & Fun Kolb Kathering (Richard Swiderski) 16. 04:32 PM - Re: Re: Land Shorter VG's on Firestar II- reply from Joa (Eugene Zimmerman) 17. 04:43 PM - Re: Re: 4th Annual Sun & Fun Kolb Kathering (John Hauck) 18. 04:52 PM - Re: Builder's List (N111KX (Kip)) 19. 05:02 PM - Re: Sun 'N Fun Ultralight Wing Walking (jerb) 20. 05:02 PM - Re: Re: Land Shorter VG's on Firestar II- reply from Joa (John Hauck) 21. 05:16 PM - Re: Re: Land Shorter VG's on Firestar II (Beauford) 22. 06:02 PM - Re: Re: Land Shorter VG's on Firestar II- reply from Joa (Richard Pike) 23. 06:03 PM - elevator authority (Eugene Zimmerman) 24. 06:05 PM - Re: center of lift (Richard Pike) 25. 06:14 PM - Re: Re: Land Shorter VG's on Firestar II- reply from Joa (Eugene Zimmerman) 26. 06:15 PM - Re: a stall between 2 fools (Robert Laird) 27. 06:16 PM - Re: Re: Land Shorter VG's on Firestar II (russ kinne) 28. 06:27 PM - Re: Re: Land Shorter VG's on Firestar II- reply from Joa (John Hauck) 29. 07:49 PM - Re: Sun 'N Fun Ultralight Wing Walking (David Lehman) 30. 09:51 PM - Re: Sun 'N Fun Ultralight Wing Walking (robert bean) ________________________________ Message 1 _____________________________________ Time: 05:01:36 AM PST US From: "pat ladd" Subject: Re: Kolb-List: a stall between 2 fools --> Kolb-List message posted by: "pat ladd" Mirable scriptu! No lift from a flat plate? Next, the battle of Bernoulli vs Newton, or who lifts yer wing?>> Zounds and forsooth!.What have I got myself into? Nevertheless, I will try to fight my corner. Yes, a flat plate, say held out of the car window at an angle, will deflect a flow of air and produce an opposite force. Held at zero angle of attack it will not. An airofoil section at zero AoA, WILL produce lift. In each case the lift is produced by changing the direction of the airflow The tail plane I contend acts like the flat plate and exerts no force until the elevator is moved. Then the tailplane and elevator, considered as one, take on a roughly airofoil shape and it is this which produces the `lift`, deflects the airflow and the resultant force moves the tail up or down. In the case of the rudder, which no one normally reckons as producing lift the same thing turns right or left. The rudder after all is only a tailplane turned through 90 degrees. I can hear the bell going for the second round already. Ding ding! Cheers Pat do not archive -- ________________________________ Message 2 _____________________________________ Time: 05:48:29 AM PST US From: "pat ladd" Subject: Re: Kolb-List: Re: Land Shorter VG's on Firestar II --> Kolb-List message posted by: "pat ladd" Did I hear someone call for a wind tunnel....?>> Hey, thats great. Can you do smoke or tufts? Pics would be nice but that is asking a bit much. The position that I am desperately trying to defend here is my contention that the tail plane alone does not exert lift. When the elevator is applied the tail plane/elevator combination DOES assume a rough airofoil shape and consequently produces some lift. In that case with VG`s on the underside of the tailplane and the elevator in the `up` position they would do exactly what they do on the top of a wing. Keep the boundary layer from breaking away. That would increase the effectiveness of the `up` elevator. Can you prove or disprove? Cheers Pat do not archive -- ________________________________ Message 3 _____________________________________ Time: 06:40:53 AM PST US Subject: Kolb-List: Re: Land Shorter VG's on Firestar II From: "John Jung" --> Kolb-List message posted by: "John Jung" Group, I tried a couple of times yesterday to get to talk to Joa from Landshorter. I also e-mailed him with a copy of Chris Mallory's post, so that he could confirm or correct. I will report to the list after I hear from him. do not archive -------- John Jung Firestar II N6163J Surprise, AZ Read this topic online here: http://forums.matronics.com/viewtopic.php?p=24768#24768 ________________________________ Message 4 _____________________________________ Time: 06:54:47 AM PST US Subject: Kolb-List: Re: Land Shorter VG's on Firestar II From: "John Jung" --> Kolb-List message posted by: "John Jung" Group, Joa did respond to the list last night. I should read everything before I reply to anything in the morning. He changed the subject line. Anyway, what he accomplished with VGs on the underside of the horizontal stab is exactly the way my Firestar II flys now. So adding them to my stab would be a waste of time and money. -------- John Jung Firestar II N6163J Surprise, AZ Read this topic online here: http://forums.matronics.com/viewtopic.php?p=24771#24771 ________________________________ Message 5 _____________________________________ Time: 06:55:42 AM PST US From: Richard Pike Subject: Re: Kolb-List: Re: Land Shorter VG's on Firestar II --> Kolb-List message posted by: Richard Pike Instead of agreeing with or denying your position, let me simply muddy the waters: For the last couple years I have been designing and building radio control airplanes out of fan fold insulating foam and typically I have given all of them a very thick airfoil because it makes it easier to build a light wing, plus creates other good flying attributes. Lately I have gone the opposite direction and currently have two airplanes that have only a flat sheet wing, reinforced by a carbon fiber tube as a main spar. And they fly just as good as the ones with a real airfoil. Obviously we are talking very light wing loadings here, but in certain applications, a flat surface produces all the lift you need. I attached some pics, maybe they will go through. In the case of a Kolb, we have several degrees of incidence between the wing and the tail, and if the airplane is properly trimmed, the elevator will be exactly aligned with the horizontal stab while in flight, and this will be providing the proper downforce to balance the center of lift of the wing with the thrust and load of the wing. And if the elevator/stab is providing downforce when undeflected, then...? (And it must of necessity be creating downforce, due to the decalage between the wing and the tail. Also, I strongly doubt that the center of lift of the Kolb airfoil would ever match the center of gravity of the airplane. Because if it would, then no decalage between the wing and tail would be necessary. Of course, it would make for a very unpleasant to fly, generally unstable airplane) Richard Pike MKIII N420P (420ldPoops) pat ladd wrote: > --> Kolb-List message posted by: "pat ladd" > > Did I hear someone call for a wind tunnel....?>> > > Hey, thats great. Can you do smoke or tufts? Pics would be nice but that is > asking a bit much. > > The position that I am desperately trying to defend here is my contention > that the tail plane alone does not exert lift. When the elevator is applied > the tail plane/elevator combination DOES assume a rough airofoil shape and > consequently produces some lift. > In that case with VG`s on the underside of the tailplane and the elevator in > the `up` position they would do exactly what they do on the top of a wing. > Keep the boundary layer from breaking away. That would increase the > effectiveness of the `up` elevator. > > Can you prove or disprove? > > Cheers > > Pat > > do not archive > > > ________________________________ Message 6 _____________________________________ Time: 07:27:29 AM PST US From: "John Hauck" Subject: Re: Kolb-List: Re: Land Shorter VG's on Firestar II- reply from Joa --> Kolb-List message posted by: "John Hauck" | Speaking of... soon after SnF a bunch of the Rans guys are going to try to get together somewhere around Alvord Desert (SE Oregon) or thereabouts and have a little informal spring fly-in. We should get some Kolbs coming too. Once I get a date and location I'll try to remember to let you all know. Lots of fun :) | | Joa The weekend between Mother's Day and Memorial Day, is reserved for the Fourth Annual UnPlanned/Unorganized Kolb Flyin, Monument Valley, UT. Everyone is welcome to attend. Last year after the MV Flyin, several of us Kolbers flew to Moab, UT, for a few days, then on up to Alvord Dessert for a few more days. Had a ball, but it turned out to be marginal because of unusually high water. However, we did have enough dry lake bed to fly off and camp on. Again, several of us plan on being in the area of the Alvord the week following our MV Flyin, which is 19-21 May 2006. Might note, some of us will arrive MV a day or two earlier than the unofficial start date of 19 May. Take care, john h ________________________________ Message 7 _____________________________________ Time: 07:59:09 AM PST US From: "Ed Chmielewski" Subject: Re: Kolb-List: a stall between 2 fools --> Kolb-List message posted by: "Ed Chmielewski" Hi Pat, I'd guess Bob's statement of "No lift from a flat plate? Next, the battle of Bernoulli vs Newton, or who lifts yer wing?" was meant tongue-in-cheek. Lift does not need an "airfoil shape" to be produced, only relative wind and angle-of-attack. In a tornado, do not houses and other large, previously unairworthy objects fly? I would heartily disagree with your statement, "Then the tailplane and elevator, considered as one, take on a roughly airofoil shape and it is this which produces the `lift`, deflects the airflow and the resultant force moves the tail up or down." The elevator in this case can be said to deflect the air (Newton) more than it creates an airfoil with the horizontal stab (Bernoulli). Combinations of principals like these explain why aerobatic aircraft with fully-symmetrical surfaces are able to fly. I would hold that there are no absolutes in aerodynamics theory, only combinations of known principals. Where's Topher when you really need him?? Ed in JXN Do not archive. ----- Original Message ----- From: "pat ladd" Sent: Tuesday, March 28, 2006 7:56 AM Subject: Re: Kolb-List: a stall between 2 fools > --> Kolb-List message posted by: "pat ladd" > > Zounds and forsooth!.What have I got myself into? > > Nevertheless, I will try to fight my corner. Yes, a flat plate, say held > out of the car window at an angle, will deflect a flow of air and produce > an > opposite force. Held at zero angle of attack it will not. An airofoil > section at zero AoA, WILL produce lift. > In each case the lift is produced by changing the direction of the airflow > The tail plane I contend acts like the flat plate and exerts no force > until > the elevator is moved. Then the tailplane and elevator, considered as one, > take on a roughly airofoil shape and it is this which produces the `lift`, > deflects the airflow and the resultant force moves the tail up or down. In > the case of the rudder, which no one normally reckons as producing lift > the > same thing turns right or left. The rudder after all is only a tailplane > turned through 90 degrees. > > I can hear the bell going for the second round already. Ding ding! > > Cheers > > Pat > > do not archive > > > -- > > > ________________________________ Message 8 _____________________________________ Time: 08:02:40 AM PST US From: "boyd" Subject: Kolb-List: center of lift --> Kolb-List message posted by: "boyd" <<<<<<<<<<<<< Mr. Ladd is correct; our tail feathers hold the tail DOWN in flight since, on our wing, the center of lift is BEHIND the center of gravity. >>>>>>>>>>>>>>>>>>>>> Forget VG's I have asked this before and not got a good response that helped me understand. I have been told, and cant say from where, that the center of lift of a wing will be around the 25% of the cord. or around the thickest part of the airfoil. On our kolbs that would be near the front wing attach point. If that is true and the rear cg is allowed to go to 35% of the wing cord or about 6 to 7 inches behind the front wing attach point.. Then the horizontal tail surface would have to be I LIFTING surface. but we know that the tail is designed to have negative lift to provide stability to the aircraft. So if Mr. Ladd is correct,,, and the tail feathers hold the tail down,,,, then the center of lift on our wings is not at 25%,,,, it must be beyond 35% of the wing cord. Am I missing something here? Boyd ________________________________ Message 9 _____________________________________ Time: 08:03:30 AM PST US Subject: Re: Kolb-List: Turbulent airfoils and barns From: Herb Gayheart --> Kolb-List message posted by: Herb Gayheart Guys No doubt a barn door will fly.. I suspect that the whole leading edge becomes one large vortex generator? :-) The problem might be in designing a horizontal stab to offset the large pitching movements? Large divergence between CG and CL?? The angle of attack between flying and stalling would be very small? If so, that would be an exciting ride! Laminar flow vs turbulent flow airfoils.. Ours are turbulent to begin with.. By definition anyhow.. Vortex generators trip the boundary layer, such as it is on a Kolb..Probably ain't much there in the first place? That is why placement must be fairly critical.. Too far back and they are in the turbulent flow which would have little effect. Pretty sure that the center of lift on the Kolb wing is in front of the spar.. is that correct? Herb do not archive On Tue, 28 Mar 2006 02:03:50 -0500 "Ed Chmielewski" writes: > --> Kolb-List message posted by: "Ed Chmielewski" > > > And Langewiesche is flippin' over about now, too. > > Ed in JXN > Do not archive. > > > ----- Original Message ----- > From: "Robert Noyer" > To: > Sent: Monday, March 27, 2006 7:33 PM > Subject: Re: Kolb-List: a stall between 2 fools > > > > ________________________________ Message 10 ____________________________________ Time: 08:37:03 AM PST US From: "pat ladd" Subject: Re: Kolb-List: a stall between 2 fools --> Kolb-List message posted by: "pat ladd" I would hold that there are no absolutes in aerodynamics theory, >> Hi Ed, the way I am struggling to hold up my end of this argument I tend to agree. After all, bumblebees are airodynamically not supposed to be able to fly. Sorry but I can not agree that because a gale blows your trailer into the next State it can be said that it is flying. I am not sure what it is doing mind you. Regarding the fact that symmetrical wings with no apparent airofoil keep high speed fighters in the air I can only assume that they are always at a small angle of attack. Then, I would agree that with sufficient power even a flat plate will fly. I still think that my example of the tail fin not producing any force in either direction until rudder is applied is valid, and if that is the way it works vertically then the same thing will work horizontally. Anyway I am off to sunny Cyprus in the Mediterranean at sparrows fart tomorrow and I hope you have all got this sorted out before I return in a weeks time. Cheers Pat do not archive -- ________________________________ Message 11 ____________________________________ Time: 12:16:34 PM PST US From: "Jeremy Casey" Subject: RE: Kolb-List: Re: Land Shorter VG's on Firestar II --> Kolb-List message posted by: "Jeremy Casey" The position that I am desperately trying to defend here is my contention that the tail plane alone does not exert lift. When the elevator is applied the tail plane/elevator combination DOES assume a rough airofoil shape and consequently produces some lift. In that case with VG`s on the underside of the tailplane and the elevator in the `up` position they would do exactly what they do on the top of a wing. Keep the boundary layer from breaking away. That would increase the effectiveness of the `up` elevator. Can you prove or disprove? Cheers Pat OK Pat...I'll answer your question with another question...if a "flat" surface can't generate lift then how the heck did the Concorde ever fly? (Or the Mirage, or F-102 Delta Dart) Point being anything that can deflect air one way will produce lift (or just call it FORCE) the other way...it's that old "For every action there is an equal and opposite REACTION" thing...Newton wasn't it? Jeremy ________________________________ Message 12 ____________________________________ Time: 12:21:52 PM PST US From: "Jeremy Casey" Subject: RE: Kolb-List: center of lift --> Kolb-List message posted by: "Jeremy Casey" Yep...the "center of lift" being at 25% chord doesn't take into account the "moment" that the airfoil produces...if it has been awhile since physics class, "moment" is a rotation...in regards to an airplane the rotation is considered positive when it tries to rotate leading edge down. So the combination of CG position AND the moment coefficient of the airfoil determines how much downforce the tail has to produce... Clear as mud? Jeremy Casey I have been told, and cant say from where, that the center of lift of a wing will be around the 25% of the cord. or around the thickest part of the airfoil. On our kolbs that would be near the front wing attach point. If that is true and the rear cg is allowed to go to 35% of the wing cord or about 6 to 7 inches behind the front wing attach point.. Then the horizontal tail surface would have to be I LIFTING surface. but we know that the tail is designed to have negative lift to provide stability to the aircraft. So if Mr. Ladd is correct,,, and the tail feathers hold the tail down,,,, then the center of lift on our wings is not at 25%,,,, it must be beyond 35% of the wing cord. Am I missing something here? Boyd ________________________________ Message 13 ____________________________________ Time: 12:25:32 PM PST US From: "Jeremy Casey" Subject: RE: Kolb-List: a stall between 2 fools --> Kolb-List message posted by: "Jeremy Casey" Nevertheless, I will try to fight my corner. Yes, a flat plate, say held out of the car window at an angle, will deflect a flow of air and produce an opposite force. Held at zero angle of attack it will not. An airofoil section at zero AoA, WILL produce lift. In each case the lift is produced by changing the direction of the airflow The tail plane I contend acts like the flat plate and exerts no force until the elevator is moved. Then the tailplane and elevator, considered as one, take on a roughly airofoil shape and it is this which produces the `lift`, deflects the airflow and the resultant force moves the tail up or down. In the case of the rudder, which no one normally reckons as producing lift the same thing turns right or left. The rudder after all is only a tailplane turned through 90 degrees. I can hear the bell going for the second round already. Ding ding! Cheers Pat do not archive Pat you shot down your own argument...your example of the flat plate out the car window explains it...even if the elevator is perfectly in line with the horizontal stab they are noticeably nose down relative to the airflow...so they are indeed generating DOWNFOCE... ;-) Jeremy Casey ________________________________ Message 14 ____________________________________ Time: 12:37:46 PM PST US From: "Larry Cottrell" Subject: Re: Kolb-List: Re: Land Shorter VG's on Firestar II- reply from Joa --> Kolb-List message posted by: "Larry Cottrell" > try to get together somewhere around Alvord Desert (SE Oregon) or > thereabouts and have a little informal spring fly-in. We should get > some Kolbs coming too. Once I get a date and location I'll try to > remember to let you all know. Lots of fun :) To all, The Alvord last year was indeed marginal because of high water. I do believe that this year will be much the same. The south end of the desert should be dry though. My wife and I will be moving into the Rock house at Burns Jct. N42 40.751 W117 51.673 by May 1st. The place is on Hwy 95 between Burns ( 95 miles north)and McDermott, Nev. (50 miles south) Jordan Valley is 38 miles east on Hwy 95. Access is through a state gravel pit at MP 72. It has a 2600 foot gravel strip and a 40x50 cinderblock hanger. It is located 30 miles (air) east of the Alvord, and about 7 miles north of Rome State. Nearest neighbor is at least a mile away, and the wind always seems to blow down the strip. We of course would like to invite all of you to come there for a visit once we have had a chance to get settled, or you could help us move. :-) It is out in the desert, (sage) If you Rans guys would like to join us up there I am sure you would be welcomed by everyone. Plenty of room to camp as well. Larry ________________________________ Message 15 ____________________________________ Time: 02:43:17 PM PST US From: "Richard Swiderski" Subject: RE: Kolb-List: Re: 4th Annual Sun & Fun Kolb Kathering --> Kolb-List message posted by: "Richard Swiderski" Kalling all Kolbers: ] Myself & George Randolph (Geo38) will be hosting a Kolb Kathering Friday evening around 6pm till whenever. My white & green trimmed UL trailer with RV awning will be in the UL trailer parking field which is immediately east of the UL airstrip, so you'll still be able to sit & watch the evening parade of ultralights. Usually we are at the east boundary of that field next to the fence line. Each year Kolb's best gather for a chance to put faces on the familiar names we see on the List, do some serious hanger flying & just have fun trading ideas or stories. Last year we built a fire in a bucket (open fires are not allowed) using artificial logs that burned with black smut & nasty smell on the downwind crowd. We learn from are mistakes so this year our campfire will be charcoal & real wood. If you arrive with a Kolb hat, a Kolb T-shirt, Kolb underwear or even a Kolb smile, you will be eligible for free tube steaks grilled to your specifications because there's a good chance you will be grilling your own Kolb-dogs! We will provide the cheap food stove & a few chairs & coolers to sit on, but bring your own chairs if you can. Several guys got chased off by the cold evening air they weren't expecting, so bring a long sleeved shirt. We will be there hopefully Wednesday AM (slight chance it will be Thursday AM) till Saturday late or Sunday early. If you need some supplies, a place to sit in the shade, or a drink of ice water during that time, feel to just drop by. If we are not there, just make yourself at home. Richard Swiderski SlingShot Turbo Suzuki ________________________________ Message 16 ____________________________________ Time: 04:32:33 PM PST US From: Eugene Zimmerman Subject: Re: Kolb-List: Re: Land Shorter VG's on Firestar II- reply from Joa --> Kolb-List message posted by: Eugene Zimmerman On Mar 28, 2006, at 1:21 AM, Land Shorter wrote: > Ok, so where I use to really notice it (besides the non-stall) is > when landing with someone in the back seat. I just didn't have the > elevator authority to quickly flare and arrest my sink rate and > ended up having to come in a little faster than normal and float a > bit more so that I wouldn't bounce. Joa, You seem to be saying you need more elevator authority to flare with someone in the back seat than you do solo, is that correct? If so, that must mean that the back seat on your Rans airplane is still in front of the center of lift. A Kolb Firestar II puts the weight of the back seat passenger very close to the center of lift and does not exhibit this lack of elevator authority you are talking about with a back seat passenger. Perhaps a side by side Mark III Kolb driver can tell us what they experience with elevator control, with or without a passenger? Do you ever feel that more elevator control would be desirable? ________________________________ Message 17 ____________________________________ Time: 04:43:34 PM PST US From: "John Hauck" Subject: Re: Kolb-List: Re: 4th Annual Sun & Fun Kolb Kathering --> Kolb-List message posted by: "John Hauck" | | Richard Swiderski Wanted to personally thank Richard and George for their offer of hospitality. I plan to fly down Monday. Will be living with the airplane for the week, so will be obliged, especially in the evening, if anyone is going to town for chow. Something about Sun and Fun that encourages starvation. Plan on camping in the UL tiedown area at the NE corner of the UL airstrip with Miss P'fer. Ya'll come by and sit a spell. The porch lights on and the door is always open. john h MKIII DO NOT ARCHIVE ________________________________ Message 18 ____________________________________ Time: 04:52:04 PM PST US Subject: Kolb-List: Re: Builder's List From: "N111KX (Kip)" --> Kolb-List message posted by: "N111KX (Kip)" Hi gents. The database portion of my site is still down. You can email me at anytime for info on the list. Sorry about the problems... Regards, Kip n111kx@mindspring.com -------- Kip Firestar II (born September 2000) Atlanta, GA N111KX Read this topic online here: http://forums.matronics.com/viewtopic.php?p=24891#24891 ________________________________ Message 19 ____________________________________ Time: 05:02:52 PM PST US From: jerb Subject: Re: Kolb-List: Sun 'N Fun Ultralight Wing Walking --> Kolb-List message posted by: jerb What month issue was that, April like as in April Fools.... jerb At 07:03 PM 3/27/2006, you wrote: >--> Kolb-List message posted by: "Bill Vincent" > >Hi Gang > >I just received my April, Ultralight Flying magazine, and I noticed >that at Sun 'N Fun this year at the Friday Night airshow, on April >7th, they are featuring a father/daughter Ultralight Wing Walking >show. It is the team of Bob Essell and his daughter Jennie Forsythe; >this is first time I have ever heard of an Ultralight Wing Walking act. > >Bill Vincent >Firestar II >Upper Peninsula of Michigan > >Do Not Archive > > ________________________________ Message 20 ____________________________________ Time: 05:02:52 PM PST US From: "John Hauck" Subject: Re: Kolb-List: Re: Land Shorter VG's on Firestar II- reply from Joa --> Kolb-List message posted by: "John Hauck" | experience with elevator control, with or without a passenger? Do you | ever feel that more elevator control would be desirable? | Gene: To answer the first question, pull back, nose goes up and tail goes down,............................... ;-) Sorry could not resist. Seriously, if I needed more elevator control, I would stick those little thing on the bottom of my horizontal stabilizers. With a real lard ass in the left seat, it does not pay to approach a 3 pt landing too slowly. Probably, could use more elevator control during a situation like that. However, I am normally solo with gear in the rear cargo compartment and 150 lbs of fuel in the normally upper rear open area in a MKIII. So......I have plenty pitch control. john h MKIII ________________________________ Message 21 ____________________________________ Time: 05:16:32 PM PST US From: "Beauford" Subject: Re: Kolb-List: Re: Land Shorter VG's on Firestar II --> Kolb-List message posted by: "Beauford" Brother Patrick... Prove...? Disprove...? Lift...? Your induced-airfoil theory makes intuitive sense to me... But, nossir, I can only offer my empirical before and after impressions... flare the little airplane down in ground effect, power off, with my flabby butt strapped in the pointy end, and there is a markedly reduced tendency to perform a soil-sampling drill when the VG's are installed on the bottom of the tail... Per your inquiries... Smoke is available if you furnish the Macanudo... I no longer do tufts... it's a matter of principle, Sir... Pictures are most assuredly out of the question... we have our standards.... Beauford of Brandon FF#076 Do Not Archive ----- Original Message ----- From: "pat ladd" Sent: Tuesday, March 28, 2006 8:43 AM Subject: Re: Kolb-List: Re: Land Shorter VG's on Firestar II > --> Kolb-List message posted by: "pat ladd" > > > Hey, thats great. Can you do smoke or tufts? Pics would be nice but that is > asking a bit much. > > The position that I am desperately trying to defend here is my contention > that the tail plane alone does not exert lift. When the elevator is applied > the tail plane/elevator combination DOES assume a rough airofoil shape and > consequently produces some lift. > > Can you prove or disprove? > > > > > -- > > ________________________________ Message 22 ____________________________________ Time: 06:02:44 PM PST US From: Richard Pike Subject: Re: Kolb-List: Re: Land Shorter VG's on Firestar II- reply from Joa --> Kolb-List message posted by: Richard Pike The MKIII with full flaps and a heavy passenger is starting to run out of elevator authority. If you have to make a go around type maneuver - it is good to practice this at altitude, because with full power and full flaps, the high thrust line and center of lift travel induced by the flaps will open your eyes. it is not anything dangerous, but the usual Kolb elevator authority is just not there the way you typically expect. If you land with a heavy passenger, full flaps, and VG's, you can shoot the approach at 45 mph (indicated) but then you don't have enough elevator authority to flare. Full aft stick changes nothing. Surprise! And yes, more elevator authority in that situation would be good. Richard Pike MKIII n420P (420ldPoops) Eugene Zimmerman wrote: > --> Kolb-List message posted by: Eugene Zimmerman > > > On Mar 28, 2006, at 1:21 AM, Land Shorter wrote: > > >> Ok, so where I use to really notice it (besides the non-stall) is >> when landing with someone in the back seat. I just didn't have the >> elevator authority to quickly flare and arrest my sink rate and >> ended up having to come in a little faster than normal and float a >> bit more so that I wouldn't bounce. >> > > Joa, > > You seem to be saying you need more elevator authority to flare with > someone in the back seat than you do solo, is that correct? > > If so, that must mean that the back seat on your Rans airplane is > still in front of the center of lift. > > A Kolb Firestar II puts the weight of the back seat passenger very > close to the center of lift and does not exhibit this lack of > elevator authority you are talking about with a back seat passenger. > > Perhaps a side by side Mark III Kolb driver can tell us what they > experience with elevator control, with or without a passenger? Do you > ever feel that more elevator control would be desirable? > > > > > > > > ________________________________ Message 23 ____________________________________ Time: 06:03:55 PM PST US From: Eugene Zimmerman Subject: Kolb-List: elevator authority --> Kolb-List message posted by: Eugene Zimmerman Ah John, You make another good point! Having the weight of the fuel up closer to the wing rather than down low would make it easier for the elevator to rotate the plane. As a plane rotates to a nose high attitude the weight of a lower fuel tank moves front further in relation to the center of lift than the weight of a fuel tank up closer to the wing. One hundred and fifty pounds is a pretty significant pendulum to try to swing. On Mar 28, 2006, at 8:02 PM, John Hauck wrote: > Seriously, if I needed more elevator control, I would stick those > little thing on the bottom of my horizontal stabilizers. > > With a real lard ass in the left seat, it does not pay to approach a 3 > pt landing too slowly. Probably, could use more elevator control > during a situation like that. However, I am normally solo with gear > in the rear cargo compartment and 150 lbs of fuel in the normally > upper rear open area in a MKIII. So......I have plenty pitch control. > > john h > MKIII ________________________________ Message 24 ____________________________________ Time: 06:05:36 PM PST US From: Richard Pike Subject: Re: Kolb-List: center of lift --> Kolb-List message posted by: Richard Pike Yes - and it is easy to miss - although the center of lift can be at 25% or 35 % or where ever, the whole chord of the wing is still producing lift, and most of the wing is still going to be behind the CG. So regardless of where the wing produces the greatest lift, the sum total of lift produced will always be behind the CG. Unless you get the CG terribly wrong... But with the sum total of lift behind the CG, the tail surfaces keep the wing from rotating around the CG, so they are stabilizing the airplane, or in effect, holding the tail down. Good question. Richard Pike MKIII N420P (420ldPoops) boyd wrote: > --> Kolb-List message posted by: "boyd" > > <<<<<<<<<<<<< > > Mr. Ladd is correct; our tail feathers hold the tail DOWN in flight since, > on our wing, the center of lift is BEHIND the center of gravity. > > > > Forget VG's I have asked this before and not got a good response that > helped me understand. > > I have been told, and cant say from where, that the center of lift of a wing > will be around the 25% of the cord. or around the thickest part of the > airfoil. On our kolbs that would be near the front wing attach point. > If that is true and the rear cg is allowed to go to 35% of the wing cord or > about 6 to 7 inches behind the front wing attach point.. Then the > horizontal tail surface would have to be I LIFTING surface. but we know > that the tail is designed to have negative lift to provide stability to the > aircraft. So if Mr. Ladd is correct,,, and the tail feathers hold the > tail down,,,, then the center of lift on our wings is not at 25%,,,, it > must be beyond 35% of the wing cord. > > Am I missing something here? > > Boyd > > > > > > > > ________________________________ Message 25 ____________________________________ Time: 06:14:52 PM PST US From: Eugene Zimmerman Subject: Re: Kolb-List: Re: Land Shorter VG's on Firestar II- reply from Joa --> Kolb-List message posted by: Eugene Zimmerman Thanks, Richard Have you tried the VGs for that situation yet? On Mar 28, 2006, at 9:00 PM, Richard Pike wrote: > --> Kolb-List message posted by: Richard Pike > > The MKIII with full flaps and a heavy passenger is starting to run out > of elevator authority. If you have to make a go around type maneuver - > it is good to practice this at altitude, because with full power and > full flaps, the high thrust line and center of lift travel induced by > the flaps will open your eyes. it is not anything dangerous, but the > usual Kolb elevator authority is just not there the way you typically > expect. > > If you land with a heavy passenger, full flaps, and VG's, you can > shoot > the approach at 45 mph (indicated) but then you don't have enough > elevator authority to flare. Full aft stick changes nothing. Surprise! > And yes, more elevator authority in that situation would be good. > > Richard Pike > MKIII n420P (420ldPoops) > ________________________________ Message 26 ____________________________________ Time: 06:15:00 PM PST US From: "Robert Laird" Subject: Re: Kolb-List: a stall between 2 fools --> Kolb-List message posted by: "Robert Laird" Sorry to butt in with my 2-cents, but, "flying" implies some kind of control, otherwise, it's just falling with style (apologies to B. Lightyear). A house sucked up into a tornado (which, by every image I've seen, is no longer a house but a collection of boards), a piece of plywood being blown around by a hurricane... these items are not flying. There is no control. A parachutist who simply jumps and does nothing else is simply falling. But if the parachutist purposefully changes direction, moves away then back, and all those other fancy moves I've seen them do, then I'd say they were flying. Just as surely as a hawk, diving from way above on to a hapless dove, would be flying. Thus, an tail section, since there is control, no matter how flat, providing no lift, positive lift, or negative lift, is flying. -- Robert On 3/28/06, Ed Chmielewski wrote: > --> Kolb-List message posted by: "Ed Chmielewski" > > Hi Pat, > > I'd guess Bob's statement of "No lift from a flat plate? Next, the > battle of Bernoulli vs Newton, or who lifts yer wing?" was meant > tongue-in-cheek. Lift does not need an "airfoil shape" to be produced, only > relative wind and angle-of-attack. In a tornado, do not houses and other > large, previously unairworthy objects fly? I would heartily disagree with > your statement, "Then the tailplane and elevator, considered as one, take on > a roughly airofoil shape and it is this which produces the `lift`, deflects > the airflow and the resultant force moves the tail up or down." The > elevator in this case can be said to deflect the air (Newton) more than it > creates an airfoil with the horizontal stab (Bernoulli). Combinations of > principals like these explain why aerobatic aircraft with fully-symmetrical > surfaces are able to fly. > I would hold that there are no absolutes in aerodynamics theory, > only combinations of known principals. > > Where's Topher when you really need him?? > > Ed in JXN > Do not archive. > > > ----- Original Message ----- > From: "pat ladd" > To: > Sent: Tuesday, March 28, 2006 7:56 AM > Subject: Re: Kolb-List: a stall between 2 fools > > > > --> Kolb-List message posted by: "pat ladd" > > > > Zounds and forsooth!.What have I got myself into? > > > > Nevertheless, I will try to fight my corner. Yes, a flat plate, say held > > out of the car window at an angle, will deflect a flow of air and produce > > an > > opposite force. Held at zero angle of attack it will not. An airofoil > > section at zero AoA, WILL produce lift. > > In each case the lift is produced by changing the direction of the airflow > > The tail plane I contend acts like the flat plate and exerts no force > > until > > the elevator is moved. Then the tailplane and elevator, considered as one, > > take on a roughly airofoil shape and it is this which produces the `lift`, > > deflects the airflow and the resultant force moves the tail up or down. In > > the case of the rudder, which no one normally reckons as producing lift > > the > > same thing turns right or left. The rudder after all is only a tailplane > > turned through 90 degrees. > > > > I can hear the bell going for the second round already. Ding ding! > > > > Cheers > > > > Pat > > > > do not archive > > > > > > > > -- > > > > > > > > > > > > > > > > > > > > > > > > > > > > ________________________________ Message 27 ____________________________________ Time: 06:16:28 PM PST US From: russ kinne Subject: Re: Kolb-List: Re: Land Shorter VG's on Firestar II --> Kolb-List message posted by: russ kinne Pat As I understand it, the tailplane does create "lift", but in an upward direction -- because it is behind the CG. In effect, it keeps the tail DOWN. Which is why it's basically an upside-down wing, and the VG's should be on the underside. I think your contention is wrong, desperate or not. but I could be wrong; that happened once. Or twice. Best, Russ do not archive On Mar 28, 2006, at 8:43 AM, pat ladd wrote: > --> Kolb-List message posted by: "pat ladd" > > Did I hear someone call for a wind tunnel....?>> > > Hey, thats great. Can you do smoke or tufts? Pics would be nice but > that is > asking a bit much. > > The position that I am desperately trying to defend here is my > contention > that the tail plane alone does not exert lift. When the elevator is > applied > the tail plane/elevator combination DOES assume a rough airofoil > shape and > consequently produces some lift. > In that case with VG`s on the underside of the tailplane and the > elevator in > the `up` position they would do exactly what they do on the top of > a wing. > Keep the boundary layer from breaking away. That would increase the > effectiveness of the `up` elevator. > > Can you prove or disprove? > > Cheers > > Pat > > do not archive > > > -- > > ________________________________ Message 28 ____________________________________ Time: 06:27:38 PM PST US From: "John Hauck" Subject: Re: Kolb-List: Re: Land Shorter VG's on Firestar II- reply from Joa --> Kolb-List message posted by: "John Hauck" out | of elevator authority. | | Richard Pike Richard is certainly correct here. Full flaps, heavy passenger, full power, is a very undesirable situation. Best ease those flaps up as you come in with full power to go around. I don't like flying solo with full flaps and full power, although it will fly this configuration. john h MKIII ________________________________ Message 29 ____________________________________ Time: 07:49:12 PM PST US From: "David Lehman" Subject: Re: Kolb-List: Sun 'N Fun Ultralight Wing Walking --> Kolb-List message posted by: "David Lehman" Look here: http://www.bobessellairshows.com/ DVD On 3/28/06, jerb wrote: > > --> Kolb-List message posted by: jerb > > What month issue was that, April like as in April Fools.... > jerb > > At 07:03 PM 3/27/2006, you wrote: > >--> Kolb-List message posted by: "Bill Vincent" > > > >Hi Gang > > > >I just received my April, Ultralight Flying magazine, and I noticed > >that at Sun 'N Fun this year at the Friday Night airshow, on April > >7th, they are featuring a father/daughter Ultralight Wing Walking > >show. It is the team of Bob Essell and his daughter Jennie Forsythe; > >this is first time I have ever heard of an Ultralight Wing Walking act. > > > >Bill Vincent > >Firestar II > >Upper Peninsula of Michigan > > > >Do Not Archive > ________________________________ Message 30 ____________________________________ Time: 09:51:29 PM PST US From: robert bean Subject: Re: Kolb-List: Sun 'N Fun Ultralight Wing Walking --> Kolb-List message posted by: robert bean I've been called that myself... "that Bob, he's an essell!" do not archive On 28, Mar 2006, at 10:46 PM, David Lehman wrote: > --> Kolb-List message posted by: "David Lehman" > > Look here: > > http://www.bobessellairshows.com/ > > DVD > > > On 3/28/06, jerb wrote: >> >> --> Kolb-List message posted by: jerb >> >> What month issue was that, April like as in April Fools.... >> jerb >> >> At 07:03 PM 3/27/2006, you wrote: >>> --> Kolb-List message posted by: "Bill Vincent" >>> >>> >>> Hi Gang >>> >>> I just received my April, Ultralight Flying magazine, and I noticed >>> that at Sun 'N Fun this year at the Friday Night airshow, on April >>> 7th, they are featuring a father/daughter Ultralight Wing Walking >>> show. It is the team of Bob Essell and his daughter Jennie Forsythe; >>> this is first time I have ever heard of an Ultralight Wing Walking >>> act. >>> >>> Bill Vincent >>> Firestar II >>> Upper Peninsula of Michigan >>> >>> Do Not Archive >> > >