---------------------------------------------------------- KIS-List Digest Archive --- Total Messages Posted Tue 07/06/10: 8 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 09:44 AM - KIS TR-1 Aerodynamics () 2. 10:04 AM - SV: SV: Re: KIS IT-1 Aerodynamics (Hans Christian Erstad) 3. 10:14 AM - Re: SV: SV: Re: KIS IT-1 Aerodynamics (Mark Kettering) 4. 10:26 AM - Re: SV: SV: Re: KIS IT-1 Aerodynamics (Conners, Jerry L) 5. 10:42 AM - Re: SV: SV: Re: KIS IT-1 Aerodynamics (Richard Trickel) 6. 10:44 AM - SV: SV: Re: KIS IT-1 Aerodynamics - Julians mod (Hans Christian Erstad) 7. 10:52 AM - Re: [QUAR] Re: SV: SV: Re: KIS IT-1 Aerodynamics (Conners, Jerry L) 8. 12:32 PM - Re: [QUAR] Re: SV: SV: Re: KIS IT-1 Aerodynamics (Mark Kettering) ________________________________ Message 1 _____________________________________ Time: 09:44:42 AM PST US From: Subject: KIS-List: KIS TR-1 Aerodynamics 7/6/2010 Hello Fellow KIS TR-1 Builders and Flyers, I am impressed with the number of postings on this subject -- not all under the same subject line. Obviously the interest is fairly high, at least among a few of us. For those interested in learning more about the effects of wing to fuselage interface effects on airflow going back to the horizontal tail surfaces you might investigate the RV-8 situation. I won't try to bias what you might learn in that arena, but let me say a few words about strakes versus vortex generators. The two terms are used indiscriminately by many writers so there apparently is no commonly accepted distinguishing definition between the two terms or devices. An opinion that I hold is that the primary function of a strake is to change the direction of airflow while the primary function of a vortex generator is change the nature of the airflow energy from streamlines to turbulence by generating a vortex, but this opinion is not universally held. Strakes tend to be fewer in number and large while vortex generators tend to be smaller in number and many used. It is possible that one kind of device, regardless of how named, could perform both functions. Just google some terms like strakes, vortex generators, RV-8 airflow, and the like and you will be off to the races -- have fun. 'OC' Baker Says: "The best investment we can make is the time and effort to gather and understand knowledge." PS: You might also encounter the fact that automobiles are into airflow modification devices aside from spoilers. ________________________________ Message 2 _____________________________________ Time: 10:04:35 AM PST US From: "Hans Christian Erstad" Subject: SV: SV: KIS-List: Re: KIS IT-1 Aerodynamics Tim My Numbers: Main gear axle: STA 73.6 (my construction manual says 73.5, so meybe I did not follow it 100% after all :) Nose gear axle: STA 21.2 Firewall rear face (ref point): STA 32 (73.6-32=41.6) See also http://home.c2i.net/h-erstad/ Weight&Balance report Hans Christian -----Opprinnelig melding----- Fra: owner-kis-list-server@matronics.com [mailto:owner-kis-list-server@matronics.com] P vegne av F. Tim Yoder Sendt: 6. juli 2010 00:52 Til: kis-list@matronics.com Emne: 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 3 _____________________________________ Time: 10:14:30 AM PST US From: Mark Kettering Subject: Re: SV: SV: KIS-List: Re: KIS IT-1 Aerodynamics Hello Tim, At gross weight and with 20 degrees of flaps the theoretical calculated stall with the airfoil on the TR1 would be 60.5 mph. This number is using the standard definition for the wing area, length X cord. Since some of the "area" is inside the fuselage the actual usable area (area generating lift) is slightly less so making a ball park adjustment I would guess actual stall speed would be about 63 mph. This does also not take into account the added "weight" from the tail down force that of course the wing also needs to support. Of course when we build the planes they are not perfect or the same so maybe your stall is slightly different and generally higher. So, 65 mph is not at all far off from stall. And as someone recently implied, the pitot airspeed may not be accurate especially at low speeds. At gross the TR1 is not at all a STOL type aircraft. The wing is just too small and short. But it is a good all around performer with a fair cruise speed and a fair landing speed. Thanks, Mark ________________________________ Message 4 _____________________________________ Time: 10:26:10 AM PST US Subject: RE: SV: SV: KIS-List: Re: KIS IT-1 Aerodynamics From: "Conners, Jerry L" My experiences flying N94K (KIS TR-1 with Lycoming O-235 L2C) at slow speeds at high altitudes (8000-14500 MSL) and full fuel with pilot only...the aircraft does not stall at 35 knots but the resulting extreme low tail attitude prevents landing at such speeds. What are the recorded slow flight speeds being experienced by other TR-1 pilots? Jer Jerry Conners, PE Civil Engineer Nevada Department of Transportation 310 Galletti Way Sparks, Nevada 89431 775-834-8363 (voice mail) jconners@dot.state.nv.us -----Original Message----- From: owner-kis-list-server@matronics.com [mailto:owner-kis-list-server@matronics.com] On Behalf Of Mark Kettering Sent: Tuesday, July 06, 2010 6:54 AM Subject: Re: SV: SV: KIS-List: Re: KIS IT-1 Aerodynamics Hello Tim, At gross weight and with 20 degrees of flaps the theoretical calculated stall with the airfoil on the TR1 would be 60.5 mph. This number is using the standard definition for the wing area, length X cord. Since some of the "area" is inside the fuselage the actual usable area (area generating lift) is slightly less so making a ball park adjustment I would guess actual stall speed would be about 63 mph. This does also not take into account the added "weight" from the tail down force that of course the wing also needs to support. Of course when we build the planes they are not perfect or the same so maybe your stall is slightly different and generally higher. So, 65 mph is not at all far off from stall. And as someone recently implied, the pitot airspeed may not be accurate especially at low speeds. At gross the TR1 is not at all a STOL type aircraft. The wing is just too small and short. But it is a good all around performer with a fair cruise speed and a fair landing speed. Thanks, Mark This communication, including any attachments, may contain confidential information and is intended only for the individual or entity to whom it is addressed. Any review, dissemination or copying of this communication by anyone other than the intended recipient is strictly prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and delete all copies of the original message. ________________________________ Message 5 _____________________________________ Time: 10:42:41 AM PST US From: Richard Trickel Subject: RE: SV: SV: KIS-List: Re: KIS IT-1 Aerodynamics Hi Jerry Thanks for logging in.- You say the plane stalls 35 Knots so I=B4m guessi ng that is indicated.- Have you tried to compare with a gps in different directions to compensate for the wind.. Your number is very low. Rich --- On Tue, 7/6/10, Conners, Jerry L wrote: From: Conners, Jerry L Subject: RE: SV: SV: KIS-List: Re: KIS IT-1 Aerodynamics s> My experiences flying N94K (KIS TR-1 with Lycoming O-235 L2C) at slow speed s at high altitudes (8000-14500 MSL) and full fuel with pilot only...the ai rcraft does not stall at 35 knots but the resulting extreme low tail attitu de prevents landing at such speeds. What are the recorded slow flight speeds being experienced by other TR-1 pi lots? Jer Jerry Conners, PE Civil Engineer Nevada Department of Transportation 310 Galletti Way Sparks, Nevada 89431 775-834-8363 (voice mail) jconners@dot.state.nv.us -----Original Message----- From: owner-kis-list-server@matronics.com [mailto:owner-kis-list-server@mat ronics.com] On Behalf Of Mark Kettering Sent: Tuesday, July 06, 2010 6:54 AM Subject: Re: SV: SV: KIS-List: Re: KIS IT-1 Aerodynamics Hello Tim, At gross weight and with 20 degrees of flaps the theoretical calculated sta ll with the airfoil on the TR1 would be 60.5 mph.- This number is using t he standard definition for the wing area, length X cord.- Since some of t he "area" is inside the fuselage the actual usable area (area generating li ft) is slightly less so making a ball park adjustment I would guess actual stall speed would be about 63 mph.- This does also not take into account the added "weight" from the tail down force that of course the wing also ne eds to support.- Of course when we build the planes they are not perfect or the same so maybe your stall is slightly different and generally higher. - So, 65 mph is not at all far off from stall.- And as someone recently implied, the pitot airspeed may not be accurate especially at low speeds. At gross the TR1 is not at all a STOL type aircraft.- The wing is just to o small and short.- But it is a good all around performer with a fair cru ise speed and a fair landing speed. Thanks, Mark This communication, including any attachments, may contain confidential inf ormation and is intended only for the individual or entity to whom it is ad dressed. Any review, dissemination or copying of this communication by anyo ne other than the intended recipient is strictly prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and dele te all copies of the original message. le, List Admin. =0A=0A=0A ________________________________ Message 6 _____________________________________ Time: 10:44:40 AM PST US From: "Hans Christian Erstad" Subject: SV: SV: KIS-List: Re: KIS IT-1 Aerodynamics - Julians mod Tim Yes, Julians was a tail dragger, and he was operating from what I would call "STOL fields". He is now building a GlaStar, and he is not on this forum anymore? I have encosed a picture I took of Julians plane in 2004 at Stauning, Denmark. I should have taken the photo from the rear, to show the fairing from that angle. In my understaning, the fairing can start with a small radius at the leading endge, and should increase the radius toward the rear. Julian had what looked like a constant radius. But as Mark comment - and I also agree on - is that we want some warning of "close to stall condition". Apparently Lancair have a bad stall-crach record, and Lancair owners I know have installed AOA system with audible warning. ("ear-shaker" instead of stick-shaker?) Again, regards, Hans Christian -----Opprinnelig melding----- Fra: owner-kis-list-server@matronics.com [mailto:owner-kis-list-server@matronics.com] P=E5 vegne av F. Tim Yoder Sendt: 6. juli 2010 00:52 Til: kis-list@matronics.com Emne: 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 7 _____________________________________ Time: 10:52:55 AM PST US Subject: RE: [QUAR] RE: SV: SV: KIS-List: Re: KIS IT-1 Aerodynamics From: "Conners, Jerry L" Yes, 35 knots indicated but I did not say stalls at 35 knots but slow fligh t at 35 knots...I usually do the maneuver above 6000 AGL with winds at alti tude less than 10 knots...my GPS readouts are usually set for groundspeed and I have not been interested enough to confirm 35knot slow speed (Note... N94K did not stall under those slow flight speeds...I was reluctant to redu ce airspeed...) I have not done such maneuvers since 2004...went on to oth er N94K 'studies'. From: owner-kis-list-server@matronics.com [mailto:owner-kis-list-server@mat ronics.com] On Behalf Of Richard Trickel Sent: Tuesday, July 06, 2010 10:41 AM Subject: [QUAR] RE: SV: SV: KIS-List: Re: KIS IT-1 Aerodynamics Importance: Low Hi Jerry Thanks for logging in. You say the plane stalls 35 Knots so I=B4m guessing that is indicated. Have you tried to compare with a gps in different dire ctions to compensate for the wind.. Your number is very low. Rich --- On Tue, 7/6/10, Conners, Jerry L wrote: From: Conners, Jerry L Subject: RE: SV: SV: KIS-List: Re: KIS IT-1 Aerodynamics To: kis-list@matronics.com Date: Tuesday, July 6, 2010, 5:21 PM us > My experiences flying N94K (KIS TR-1 with Lycoming O-235 L2C) at slow spee ds at high altitudes (8000-14500 MSL) and full fuel with pilot only...the a ircraft does not stall at 35 knots but the resulting extreme low tail attit ude prevents landing at such speeds. What are the recorded slow flight speeds being experienced by other TR-1 p ilots? Jer Jerry Conners, PE Civil Engineer Nevada Department of Transportation 310 Galletti Way Sparks, Nevada 89431 775-834-8363 (voice mail) jconners@dot.state.nv.us -----Original Message----- From: owner-kis-list-server@matronics.com [mailto:owner-kis-li st-server@matronics.com ] On Behalf Of Mark Kettering Sent: Tuesday, July 06, 2010 6:54 AM To: kis-list@matronics.com Subject: Re: SV: SV: KIS-List: Re: KIS IT-1 Aerodynamics p://us.mc1107.mail.yahoo.com/mc/compose?to=mantafs@earthlink.net> > Hello Tim, At gross weight and with 20 degrees of flaps the theoretical calculated st all with the airfoil on the TR1 would be 60.5 mph. This number is using th e standard definition for the wing area, length X cord. Since some of the "area" is inside the fuselage the actual usable area (area generating lift) is slightly less so making a ball park adjustment I would guess actual sta ll speed would be about 63 mph. This does also not take into account the a dded "weight" from the tail down force that of course the wing also needs t o support. Of course when we build the planes they are not perfect or the same so maybe your stall is slightly different and generally higher. So, 6 5 mph is not at all far off from stall. And as someone recently implied, t he pitot airspeed may not be accurate especially at low speeds. At gross the TR1 is not at all a STOL type aircraft. The wing is just too small and short. But it is a good all around performer with a fair cruise speed and a fair landing speed. Thanks, Mark This communication, including any attachments, may contain confidential in formation and is intended only for the individual or entity to whom it is a ddressed. Any review, dissemination or copying of this communication by any one other than the intended recipient is strictly prohibited. If you are no t the intended recipient, please contact the sender by reply e-mail and del ete all copies of the tor?KIS-List" sp;--> http://f= - List C ontributionsp; &bsp;--> ========== ========== ========== ========== This communication, including any attachments, may contain confidential inf ormation and is intended only for the individual or entity to whom it is ad dressed. Any review, dissemination or copying of this communication by anyo ne other than the intended recipient is strictly prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and dele te all copies of the original message. ________________________________ Message 8 _____________________________________ Time: 12:32:30 PM PST US From: Mark Kettering Subject: RE: [QUAR] RE: SV: SV: KIS-List: Re: KIS IT-1 Aerodynamics Please keep in mind that there could be a very large difference between actual and indicated airspeed at 35 knots (~40 mph) indicated. Pitots tend to have large errors when not aligned with the airflow. The calculated stall airspeed I did is power off. The power on stall airspeed is highly dependent on the thrust. For example if the trust was very high, say 1450 lbs static, the power on stall speed would be zero at a gross of 1450 lbs. Rich's TR1 had 125 hp and depending on the prop it maybe could produce about 600 lbs of thrust at about 35 knots. This thrust would greatly lower the stall speed. The plane may also not truly stall with so much trust but could just mush along. And of course weight also has a big effect on stall speed. For example the calculated power off stall speed at 1200 lbs is 55 mph (48 knots). 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