---------------------------------------------------------- KIS-List Digest Archive --- Total Messages Posted Mon 07/05/10: 8 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 04:32 AM - Re: Nose Slam 1 & 1.5 () 2. 11:23 AM - Re: SV: Re: KIS IT-1 Aerodynamics (Mark Kettering) 3. 03:23 PM - SV: SV: Re: KIS IT-1 Aerodynamics (Hans Christian Erstad) 4. 03:53 PM - Re: SV: Re: KIS IT-1 Aerodynamics (F. Tim Yoder) 5. 06:50 PM - TR! TO tests (tmclam@comcast.net) 6. 07:39 PM - Re: TR! TO tests (F. Tim Yoder) 7. 08:47 PM - Re: SV: SV: Re: KIS IT-1 Aerodynamics (Mark Kettering) 8. 10:08 PM - Re: SV: SV: Re: KIS IT-1 Aerodynamics (F. Tim Yoder) ________________________________ Message 1 _____________________________________ Time: 04:32:00 AM PST US From: Subject: Re: KIS-List: Nose Slam 1 & 1.5 7/5/2010 Hello Ted, You wrote: 1) "Nose Slam" I don't describe it as a nose slam, just a touch down of the nose wheel, shortly after the main landing gear touch down, that I would like to avoid if I choose to do so. 2) "OC perhaps removing approximately 20 # forward of the main gear would help the "nose slam problem". Perhaps, but one must take into account CG limitations. A CG location aft in excess of the limitations could be dangerous. 3) ".!0 # under the Spinner could be demonstrated by temporarily using a borrowed wood propeller." My current prop is a laminated wood Prince prop. 4) "We should easily obtain a significant instrument panel weight reduction." I am all for weight reduction and would like to eliminate my vacuum pump and related hardware, but a new instrument panel does not quite fit into the easily category in my estimation. 5) "........... are you sure you installed the main gear wedges in the right direction?" Yep, moved the main landing gear forward. 'OC' Baker Says: "The best investment we can make is the time and effort to gather and understand knowledge." ========================================================== ----- Original Message ----- From: Sent: Sunday, July 04, 2010 8:32 AM Subject: KIS-List: Nose Slam 1 > OC,Mark,Rich and all > These recent discussions are fantastic.More to the point. > OC perhaps removing approximately 20 # forward of the main gear would help > the "nose slam problem".!0 # under the Spinner could be demonstrated by > temporarily using a borrowed wood propeller.If this does not quite do it > ,we should all take a hard look at the new Simplified Dynon basic 6 > displays.The larger one is visible in bright daylight. > Use of these new devices allows the removal of > Vacuum pumps > Vacuum hoses ,gages,Regulators and so on. > Heavy Attitude Horizon and Directional Gyro > We should easily obtain a significant instrument panel weight reduction.In > addition a 20# forward weight reduction will reduce trim drag and may > reduce cruise angle of attack[which equals big time drag]. > These new postage size Electronic Gyros are amazing,I think? > Ted ============================================================== ----- Original Message ----- From: Sent: Sunday, July 04, 2010 9:26 AM Subject: KIS-List: Nose Slam 1.5 > OC > Please dont feel offended but knowing what i am capable of doing are you > sure you installed the main gear wedges in the right direction? > Happy Fourth > Ted ________________________________ Message 2 _____________________________________ Time: 11:23:18 AM PST US From: Mark Kettering Subject: Re: SV: KIS-List: Re: KIS IT-1 Aerodynamics Hello Hans, >I have flown my KIS 1 for 10 years now, and I agree with 'OC' comments about >the handling with respect to difficulties making consistent landings and >keeping the nose wheel up. I have flown a TR1 with the main gear in the stock position and with that aircraft I also had the same problems. So I made some calculations and found out that the stock main gear location was too far aft. On my TR1 I then moved it forward and fully eliminated not only this problem on my aircraft but also the takeoff tendency to over rotate. When flying with Rich and watching the stick I noted that he had to pull way back to rotate then quickly release this back force and movement to prevent over rotation on lift off. >About the wing/fuselage fairing. I have meet Julian several times at >fly-in. He told that the fairing modification made the landings with a low >approach speed a lot easier. Why not believe his experience? I think he is >the only one to make the modification, and having experiencd what difference >it makes. I have fairing modification on my to-do list. But I may never >come to that item on my list, as I feel the landings are still OK, and I do >not operate from runways shorter than 800 meters. I usually keep a little >power on in the flare. Well, I am not a believer! But that has little to do with Julian's experiences. More to do with science and engineering methods. At some point with more data I may agree that the elevator loses authority due to wing fuselage junction separation. At this point I am waiting on seeing the video for myself. The one still picture I have seen does not seem to support the conclusion that the wing fuselage junction is causing separation of flow over the tail. I also never have a sudden loss or any loss of elevator authority with my aircraft at any time and I have the stock wing root fairings so this data also does not seem to support that conclusion. But this is not to say that Julian did not have this problem. Maybe his plane is slightly different than mine. Maybe my more poor (or maybe better) fit of my parts in this area prevented a problem that his plane had. Who knows? But I do do know the stock main gear location is too far aft relative to the CG (range) location. I also know that angling the gear forward (moving the gear contact point forward) reduces the hard nose let down at all CG locations and cures the tendency to over rotate. Next time you fly please try this for me but be very careful and let me know what happens! As you pull back to rotate just hold the stick in the same location and fly off the runway. This is how a good handling aircraft should takeoff. It should not need pilot input beyond a steady back pressure. You should not need to release or push forward. The plane should literally "fly itself" off the runway. But if you do this in the TR1 with the main gear in the stock location you will over rotate and need to move the stick forward. Or you will stall and maybe worse. Also please keep in mind that the gear location is very easy to change. Thanks, Mark ________________________________ Message 3 _____________________________________ Time: 03:23:39 PM PST US From: "Hans Christian Erstad" Subject: SV: SV: KIS-List: Re: KIS IT-1 Aerodynamics Thanks for comments Mark I will do the take off as you explain the next time I fly, and report back :) You mentioned "More to do with science and engineering methods". I have encosed a NACA report I found when googling for some scientific material on the subject, after I first met Julian, and he told about his modification. Interresting reading, both from an scientific and historical, point of view! Many things in our world have changed since that report were made, but the laws of physics have not changed? I have not experienced any loss of elevator authority, but feel that an approach at lowest speed needs a lot of adjustment in pitch. But close to ground there is almost always some turbulence anyway. But making control input while flying is not a problem - it is what piloting is about :) Regards, Hans Christian -----Opprinnelig melding----- Fra: owner-kis-list-server@matronics.com [mailto:owner-kis-list-server@matronics.com] P=E5 vegne av Mark Kettering Sendt: 5. juli 2010 20:18 Til: kis-list@matronics.com Emne: Re: SV: KIS-List: Re: KIS IT-1 Aerodynamics Hello Hans, >I have flown my KIS 1 for 10 years now, and I agree with 'OC' comments >about the handling with respect to difficulties making consistent >landings and keeping the nose wheel up. I have flown a TR1 with the main gear in the stock position and with that aircraft I also had the same problems. So I made some calculations and found out that the stock main gear location was too far aft. On my TR1 I then moved it forward and fully eliminated not only this problem on my aircraft but also the takeoff tendency to over rotate. When flying with Rich and watching the stick I noted that he had to pull way back to rotate then quickly release this back force and movement to prevent over rotation on lift off. >About the wing/fuselage fairing. I have meet Julian several times at >fly-in. He told that the fairing modification made the landings with a >low approach speed a lot easier. Why not believe his experience? I >think he is the only one to make the modification, and having >experiencd what difference it makes. I have fairing modification on my >to-do list. But I may never come to that item on my list, as I feel the >landings are still OK, and I do not operate from runways shorter than >800 meters. I usually keep a little power on in the flare. Well, I am not a believer! But that has little to do with Julian's experiences. More to do with science and engineering methods. At some point with more data I may agree that the elevator loses authority due to wing fuselage junction separation. At this point I am waiting on seeing the video for myself. The one still picture I have seen does not seem to support the conclusion that the wing fuselage junction is causing separation of flow over the tail. I also never have a sudden loss or any loss of elevator authority with my aircraft at any time and I have the stock wing root fairings so this data also does not seem to support that conclusion. But this is not to say that Julian did not have this problem. Maybe his plane is slightly different than mine. Maybe my more poor (or maybe better) fit of my parts in this area prevented a problem that his plane had. Who knows? But I do do know the stock main gear location is too far aft relative to the CG (range) location. I also know that angling the gear forward (moving the gear contact point forward) reduces the hard nose let down at all CG locations and cures the tendency to over rotate. Next time you fly please try this for me but be very careful and let me know what happens! As you pull back to rotate just hold the stick in the same location and fly off the runway. This is how a good handling aircraft should takeoff. It should not need pilot input beyond a steady back pressure. You should not need to release or push forward. The plane should literally "fly itself" off the runway. But if you do this in the TR1 with the main gear in the stock location you will over rotate and need to move the stick forward. Or you will stall and maybe worse. Also please keep in mind that the gear location is very easy to change. Thanks, Mark List 7-Day ________________________________ Message 4 _____________________________________ Time: 03:53:18 PM PST US From: "F. Tim Yoder" Subject: Re: SV: KIS-List: Re: KIS IT-1 Aerodynamics Mark, 'OC' and all, My gear dimensions are as follows; Main gear axle center line to firewall is 42 1/8" " " " " " " nose gear axle center line 53" I would be interested to see your numbers. In retrospect, I do have to watch and may have to increase stick pressure in order to keep the nose gear off the runway. But I do have plenty of elevator authority to do that. Julian's plane was a tail dragger (conventional) I think. He was trying to give it STOL qualities, an oxymoron I think. I forget what he built to replace the KIS, I think it is a high wing with better STOL qualities. Mark, I am in annual now, but I will try and report on your take off procedure. That is if I don't stall, crash, and burn! Also, maybe it would be helpful to confirm final approach and touch down speeds from the GPS, if available, to confirm the accuracy of our different pitot systems at slow speeds. I you are flying alone, it might be safest to do this at altitude in a practice area. 'OC', maybe Mark and Rich are just better pilots than you and I because I use your technique for more consistent landings. Oh, Mark and 'OC' what was the thickness of your main gear shims? Are they fiberglass or aluminum or??? Tim ----- Original Message ----- From: "Mark Kettering" Sent: Monday, July 05, 2010 11:18 AM Subject: Re: SV: KIS-List: Re: KIS IT-1 Aerodynamics > > Hello Hans, > >>I have flown my KIS 1 for 10 years now, and I agree with 'OC' comments >>about >>the handling with respect to difficulties making consistent landings and >>keeping the nose wheel up. > > I have flown a TR1 with the main gear in the stock position and with that > aircraft I also had the same problems. So I made some calculations and > found out that the stock main gear location was too far aft. On my TR1 I > then moved it forward and fully eliminated not only this problem on my > aircraft but also the takeoff tendency to over rotate. When flying with > Rich and watching the stick I noted that he had to pull way back to rotate > then quickly release this back force and movement to prevent over rotation > on lift off. > >>About the wing/fuselage fairing. I have meet Julian several times at >>fly-in. He told that the fairing modification made the landings with a >>low >>approach speed a lot easier. Why not believe his experience? I think he is >>the only one to make the modification, and having experiencd what >>difference >>it makes. I have fairing modification on my to-do list. But I may never >>come to that item on my list, as I feel the landings are still OK, and I >>do >>not operate from runways shorter than 800 meters. I usually keep a little >>power on in the flare. > > Well, I am not a believer! But that has little to do with Julian's > experiences. More to do with science and engineering methods. At some > point with more data I may agree that the elevator loses authority due to > wing fuselage junction separation. At this point I am waiting on seeing > the video for myself. The one still picture I have seen does not seem to > support the conclusion that the wing fuselage junction is causing > separation of flow over the tail. I also never have a sudden loss or any > loss of elevator authority with my aircraft at any time and I have the > stock wing root fairings so this data also does not seem to support that > conclusion. > > But this is not to say that Julian did not have this problem. Maybe his > plane is slightly different than mine. Maybe my more poor (or maybe > better) fit of my parts in this area prevented a problem that his plane > had. Who knows? > > But I do do know the stock main gear location is too far aft relative to > the CG (range) location. I also know that angling the gear forward > (moving the gear contact point forward) reduces the hard nose let down at > all CG locations and cures the tendency to over rotate. > > Next time you fly please try this for me but be very careful and let me > know what happens! As you pull back to rotate just hold the stick in the > same location and fly off the runway. This is how a good handling > aircraft should takeoff. It should not need pilot input beyond a steady > back pressure. You should not need to release or push forward. The plane > should literally "fly itself" off the runway. But if you do this in the > TR1 with the main gear in the stock location you will over rotate and need > to move the stick forward. Or you will stall and maybe worse. > > Also please keep in mind that the gear location is very easy to change. > > Thanks, > Mark > > > ________________________________ Message 5 _____________________________________ Time: 06:50:55 PM PST US From: tmclam@comcast.net Subject: KIS-List: TR! TO tests OC and ALL The 170 # pilot to which airplanes have been designed is obsolete in the US.Most GA pilots by the time they can afford to own an airplane are at 200# or more.A 30 to 60 # delta in the seat/s might be a troublesome moment change at TO or landing. How about including the actual pilot/s weight with your reports.What do you think Mark. Ted ________________________________ Message 6 _____________________________________ Time: 07:39:50 PM PST US From: "F. Tim Yoder" Subject: Re: KIS-List: TR! TO tests I almost always have a passenger, so my normal landing weight will be between 1362 and 1550#. Probably heaver than most. Tim N52TY ----- Original Message ----- From: tmclam@comcast.net To: kis-list@matronics.com Sent: Monday, July 05, 2010 6:49 PM Subject: KIS-List: TR! TO tests OC and ALL The 170 # pilot to which airplanes have been designed is obsolete in the US.Most GA pilots by the time they can afford to own an airplane are at 200# or more.A 30 to 60 # delta in the seat/s might be a troublesome moment change at TO or landing. How about including the actual pilot/s weight with your reports.What do you think Mark. Ted ________________________________ Message 7 _____________________________________ Time: 08:47:42 PM PST US From: Mark Kettering Subject: Re: SV: SV: KIS-List: Re: KIS IT-1 Aerodynamics Hi Hans, That is a very interesting NACA report. I think that specific aircraft design had some major issues. Plus the airfoil used has a major issue of it's own. For example the airfoil has an initial stall angle of just 8.5 degrees, right about where the tail starts to be less effective according to the report. Of course when the wing stalls then there is less down wash on the tail so there is less down force. But most engineers today think of this as a very good thing since it helps act to reduce the likely hood of a stall. If the main wing is starting to stall, then maybe there should be less down force in the tail so the plane starts to pitch down to keep more of the main wing from stalling. They also talk as if the tail buffeting is a bad thing. Of course tail flutter is but that is not at all the same as buffeting. Production aircraft today are required to have some sort of tail buffeting to warn of a stall. Planes that do not have this "stall indication" are then required to have stick shakers and/or stall horns. If you look at some production aircraft they have main wing leading edge wedges near the root to make buffeting prestall to meet this requirement. I am a big fan of the old NACA reports. I spent one summer at NASA reading a bunch of them. Many of the old reports are very applicable to our small aircraft. But at times you need to be very careful applying the information in them since at times there is a difference in goal, way of thinking or original conditions to what we have today. For example this report did not address handling qualities on any way. Yes, maybe you could keep the root from stalling first. But do you really want to? I prefer the root to stall before the center and tip since I do not like for the plane to roll into a spin when it stalls. Yes, you can eliminate tail buffeting but do you want to remove the stick shake that warns you of the impending stall? Some airfoils like the NACA M6 have preliminary and secondary stall and this can greatly effect the data but then is this data applicable to our airfoil? In any case, I think this supports my original theory in that all we are really seeing is the start of the main wing stall and it is starting at the root. Large radius fairings may reduce the local Cl at the root and then this could delay the stall at the root. But the wing will still stall. Thanks, Mark ________________________________ Message 8 _____________________________________ Time: 10:08:45 PM PST US From: "F. Tim Yoder" Subject: Re: SV: SV: KIS-List: Re: KIS IT-1 Aerodynamics Hello Mark, I was thinking that this wing would not be beginning to stall at the 80 to 65 mph short final to flair, that I think most of the reporters are indicating. Our wings are level with a low pitch angle. I understand that it is better to have the stall begin at the root but I thought it would be at below 65mph for the TR-1, is this thinking wrong? Thanks, Tim ----- Original Message ----- From: "Mark Kettering" Sent: Monday, July 05, 2010 8:45 PM Subject: Re: SV: SV: KIS-List: Re: KIS IT-1 Aerodynamics > > Hi Hans, > > That is a very interesting NACA report. I think that specific aircraft > design had some major issues. Plus the airfoil used has a major issue of > it's own. For example the airfoil has an initial stall angle of just 8.5 > degrees, right about where the tail starts to be less effective according > to the report. Of course when the wing stalls then there is less down > wash on the tail so there is less down force. But most engineers today > think of this as a very good thing since it helps act to reduce the likely > hood of a stall. If the main wing is starting to stall, then maybe there > should be less down force in the tail so the plane starts to pitch down to > keep more of the main wing from stalling. > > They also talk as if the tail buffeting is a bad thing. Of course tail > flutter is but that is not at all the same as buffeting. Production > aircraft today are required to have some sort of tail buffeting to warn of > a stall. Planes that do not have this "stall indication" are then > required to have stick shakers and/or stall horns. If you look at some > production aircraft they have main wing leading edge wedges near the root > to make buffeting prestall to meet this requirement. > > I am a big fan of the old NACA reports. I spent one summer at NASA > reading a bunch of them. Many of the old reports are very applicable to > our small aircraft. But at times you need to be very careful applying the > information in them since at times there is a difference in goal, way of > thinking or original conditions to what we have today. For example this > report did not address handling qualities on any way. Yes, maybe you > could keep the root from stalling first. But do you really want to? I > prefer the root to stall before the center and tip since I do not like for > the plane to roll into a spin when it stalls. Yes, you can eliminate tail > buffeting but do you want to remove the stick shake that warns you of the > impending stall? Some airfoils like the NACA M6 have preliminary and > secondary stall and this can greatly effect the data but then is this data > applicable to our airfoil? > > In any case, I think this supports my original theory in that all we are > really seeing is the start of the main wing stall and it is starting at > the root. Large radius fairings may reduce the local Cl at the root and > then this could delay the stall at the root. But the wing will still > stall. > > Thanks, > Mark > > > ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message kis-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/KIS-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/kis-list Browse Digests http://www.matronics.com/digest/kis-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.