From: To: Subject: krnet Digest 4 Aug 2002 10:27:22 -0000 Issue 488 Date: Sunday, August 04, 2002 3:28 AM krnet Digest 4 Aug 2002 10:27:22 -0000 Issue 488 Topics (messages 11817 through 11837): Foam, Metal, Plexi 11817 by: Peg and Mike Meyer Belly Boards 11818 by: Tim Brown the bill clapp affair 11819 by: Rick Wilson Curious... 11820 by: Jim Piunti Re: cooling under the canopy 11821 by: Rick Human 11824 by: Kenneth L Wiltrout 11826 by: Daniel Heath 11827 by: Glasco 11829 by: Daniel Heath 11830 by: Daniel Heath Bill Clapp affair 11822 by: jim . synergy design Multiple AS5046 mail 11823 by: van Rooyen, Hennie(SF02) "Raise that hood please." 11825 by: Mark Jones Waiting to fly. 11828 by: Mark Jones Re: cookout 11831 by: terry marion ks Canopy Cutting 11832 by: Mark Jones Suggestion for a wing fold mechanism 11833 by: van Rooyen, Hennie(SF02) KR2 heavier engine support idea 11834 by: van Rooyen, Hennie(SF02) Re: The AS5046 airfoil 11835 by: van Rooyen, Hennie(SF02) 11837 by: van Rooyen, Hennie(SF02) Re: The AS5046 airfoil and apology 11836 by: van Rooyen, Hennie(SF02) Administrivia: To subscribe to the digest, e-mail: To unsubscribe from the digest, e-mail: To post to the list, e-mail: ---------------------------------------------------------------------- Date: Sat, 03 Aug 2002 10:02:34 -0500 To: kr From: Peg and Mike Meyer Subject: Foam, Metal, Plexi Message-id: <018101c23afe$cca40280$4edcfea9@o0c8u6> --Boundary_(ID_8mj9uDrReTkFE+sZ7Fz1ew) Content-type: text/plain; charset=Windows-1252 Content-transfer-encoding: 7BIT For all the builders in the DFW area, let me pass on the names and addresses of three local businesses that you my find helpful. For custom cut Plexiglas at a very reasonable prices: Port Plastics 6312 Airport Frwy Fort Worth 817-834-7678 For small quantities of various metals: Metal Express 5532 Midway Rd Fort Worth 817-834-7775 For sandable foam (Trymer 2000, actually) Specialty Products Insulation Co 6504 Midway Rd Haltom City 817-831-4501 Incidentally, I made a simple solar oven to bend Plexiglas. It goes like this: cut a piece of polystyrene insulation so that it is slightly larger then the biggest piece of Plexiglas you're bending. Glue flat black construction paper on one side of the insulation. With the polystyrene laying on the ground, build a frame out of 2x4's so that it completely encloses the polystyrene. Staple some sort of clear plastic on one side of the frame. Try to make it as airtight as possible. Find a nice flat spot that gets the full brunt of the summer sun (like your driveway). Lay the polystyrene on the ground, black side up. Lay the Plexiglas on it. Put the frame around the whole thing.Stuff some rags around the perimeter of the frame to make it airtight. Add about 2-3 hours of Texas sun. When you go grab the plexi to bend it, make sure you've got some cheap flannel gloves on, because it will be hot as hell. Good Luck! Mike Meyer --Boundary_(ID_8mj9uDrReTkFE+sZ7Fz1ew)-- ------------------------------ Date: Sat, 3 Aug 2002 09:05:23 -0700 (PDT) To: Group KR NET From: Tim Brown Subject: Belly Boards Message-ID: <20020803160523.1262.qmail@web9504.mail.yahoo.com> Dear Net: I am getting ready to start construction on my belly board and below is what I am thinking about doing based on what has been posted here over the past couple years....but I also have a couple questions. My plan is to use Last-A-Foam, 1/4" covered with BID, outside edge with flox, 2" diameter holes with micro protecting the foam at the holes. Question: Is one layer of BID enough? I am also considering using a metal bracket at the belly board similar to the manual's "Outboard Hinge Bracket" on page 109. I haven't decided whether to place the "tail" towards the outside edge of the bracket, or to attach the "tail" to the hinge. Comments? I just don't know whether the metal to the edge or the metal to the hinge will be stronger. My plan is to glass one side, scrape out foam before glassing the other side and to flox the metal in place at the same time I glass the other side. Or maybe a 1/4" ply hard point would be better here with the metal bolted on through it. COMMENTS? My plan is to use a full length piano hinge for attachment. One thought I have is to flox and glass in a hard point of 1/4" ply the entire length...maybe 1" in width. Or as an alternative, glass one side, scrape away about a 1/8" of foam, coat with flox, smush (technical term) in the hinge, more flox, then glass. COMMENTS? Finally....Is there a best place to attach the belly board? Near the forward spar? Rear Spar? Split the difference? And will flox and glass be enough or should I run a few bolts through the 3/32" floor (probably with a 1/4" backer for strength) in addition to flox and glass? I'll add photos to my web site as I make progress. Thanks to all who respond. Tim __________________________________________________ Do You Yahoo!? Yahoo! Health - Feel better, live better http://health.yahoo.com ------------------------------ Date: Sat, 3 Aug 2002 09:38:52 -0700 (PDT) To: KRNET@MAILINGLISTS.ORG From: Rick Wilson Subject: the bill clapp affair Message-ID: <20020803163852.62750.qmail@web21205.mail.yahoo.com> Hi, I was reading through some of the old Kopke newsletters and found a flight report in the March '82 issue (#81) written by none other than a Mr. Bill Clapp. I don't know if it is the same one or not but his address back then was given as south America. Just thought this was kind of interesting. Rick Wilson. __________________________________________________ Do You Yahoo!? Yahoo! Health - Feel better, live better http://health.yahoo.com ------------------------------ Date: Sat, 3 Aug 2002 13:07:58 -0500 To: "KR Listserv" From: "Jim Piunti" Subject: Curious... Message-ID: ------=_NextPart_000_000E_01C23AEE.CA5B3E40 Content-Type: text/plain; charset="US-ASCII" Content-Transfer-Encoding: 7bit Do you all name your planes as we do with boats? What are some of the more creative names you've encountered? Jimmer Omaha, NE jim.piunti@cox.net ------=_NextPart_000_000E_01C23AEE.CA5B3E40-- ------------------------------ Date: Sat, 3 Aug 2002 14:30:22 -0500 To: "Darren Pond" , "krnet" From: "Rick Human" Subject: Re: KR> cooling under the canopy Message-ID: <002c01c23b24$36ad8c80$1ed80cd8@compaq> Any idea of how much noise those holes produce? ----- Original Message ----- From: "Darren Pond" To: "krnet" Sent: Saturday, August 03, 2002 11:59 AM Subject: KR> cooling under the canopy HI again I learned a little trick for keeping cool under the large glass canopies. My local EAA Darryl Gilbert drills 6 5/32 holes several inches above the front bottom edge of the canopy just below the site line. He than counter sinks them lightly. Now you have ram air. When the weather changes or cools off he take a dab of silicon and fills the holes a poke with a drill bit pops out the plug when the heat returns. He has been doing this for 14 years with good success. Darren Pond Cambridge Ontario Canada CYKF Taylor Mono plane C-FVML waiting on Transport Canada PondHopper 2.2 turbo (KR2S Heavy) Early building stages pond27@rogers.com ------------------------------ Date: Sat, 3 Aug 2002 18:28:10 -0400 To: krnet@mailinglists.org From: Kenneth L Wiltrout Subject: Re: KR> cooling under the canopy Message-ID: <20020803.182810.-298815.0.klw1953@juno.com> I gotta think there has to be a better way-------------maybe something in the side of the canopy like a snap vent. You need to drill a 2" hole on up depending how large a vent you want. When closed they are almost flush, but when open I'm sure there is some drag. > > ----- Original Message ----- > From: "Darren Pond" > To: "krnet" > Sent: Saturday, August 03, 2002 11:59 AM > Subject: KR> cooling under the canopy > > > HI again > > I learned a little trick for keeping cool under the large glass > canopies. My > local EAA Darryl Gilbert drills 6 5/32 holes several inches above > the front > bottom edge of the canopy just below the site line. He than counter > sinks > them lightly. Now you have ram air. When the weather changes or > cools off > he take a dab of silicon and fills the holes a poke with a drill bit > pops > out the plug when the heat returns. He has been doing this for 14 > years with > good success. > > Darren Pond > Cambridge Ontario Canada CYKF > Taylor Mono plane C-FVML waiting on Transport Canada > PondHopper 2.2 turbo (KR2S Heavy) Early building stages > pond27@rogers.com > > > > > --------------------------------------------------------------------- > To post to the list, email: krnet@mailinglists.org , NOT "reply all" > > To UNsubscribe, e-mail: krnet-unsubscribe@mailinglists.org > For additional commands, e-mail: krnet-help@mailinglists.org > > See the KRNet archives at http://www.maddyhome.com/krsrch/index.jsp > or http://www.bouyea.net/ for the Word files > ________________________________________________________________ GET INTERNET ACCESS FROM JUNO! Juno offers FREE or PREMIUM Internet access for less! Join Juno today! For your FREE software, visit: http://dl.www.juno.com/get/web/. ------------------------------ Date: Sat, 3 Aug 2002 20:22:30 -0700 To: From: "Daniel Heath" Subject: RE: KR> cooling under the canopy Message-ID: Jerry and I are going to put snap vents in the fuselage. I don't think I will notice the drag. Daniel R. Heath See our KR2 at: http://kr-builder.org See our EAA Chapter 242at: http://WWW.EAA242.ORG --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.325 / Virus Database: 182 - Release Date: 2/19/2002 ------------------------------ Date: Sat, 03 Aug 2002 17:50:01 -0700 To: krnet@mailinglists.org From: Glasco Subject: RE: KR> cooling under the canopy Message-Id: <3.0.6.32.20020803175001.008cd940@mail.ridgenet.net> Why not NASA ducts in the side? One on each side ought to work fine. Brad Glasco At 08:22 PM 8/3/02 -0700, you wrote: >Jerry and I are going to put snap vents in the fuselage. I don't think I >will notice the drag. > >Daniel R. Heath ------------------------------ Date: Sat, 3 Aug 2002 23:01:01 -0700 To: From: "Daniel Heath" Subject: RE: KR> cooling under the canopy Message-ID: Jerry and I are going to put snap vents in the fuselage. I don't think I will notice the drag. Daniel R. Heath See our KR2 at: http://kr-builder.org See our EAA Chapter 242at: http://WWW.EAA242.ORG --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.325 / Virus Database: 182 - Release Date: 2/19/2002 ------------------------------ Date: Sat, 3 Aug 2002 23:07:34 -0700 To: From: "Daniel Heath" Subject: RE: KR> cooling under the canopy Message-ID: NACA ducts are nice, but you must put them in a not negative pressure area. It is difficult, if not impossible to find one that you can reach from the cockpit. Daniel R. Heath See our KR2 at: http://kr-builder.org See our EAA Chapter 242at: http://WWW.EAA242.ORG --- Outgoing mail is certified Virus Free. Checked by AVG anti-virus system (http://www.grisoft.com). Version: 6.0.325 / Virus Database: 182 - Release Date: 2/19/2002 ------------------------------ Date: Sat, 3 Aug 2002 13:48:54 -0700 To: From: "jim @ synergy design" Subject: Bill Clapp affair Message-ID: <001501c23b2f$307b8be0$0101a8c0@pavilion> ------=_NextPart_000_0012_01C23AF4.820397E0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Is this also the same CLAPP listed in the NTSB KR accident reports? ------=_NextPart_000_0012_01C23AF4.820397E0-- ------------------------------ Date: Fri, 2 Aug 2002 04:16:00 -0500 To: "'krnet@mailinglists.org'" From: "van Rooyen, Hennie(SF02)" Subject: Multiple AS5046 mail Hi all, My apologies if you end up receiving three copies of the above mail. I've sent this plus two other mails with some suggested mods over five hours ago and I'm not sure if I'm doing something wrong or is this the standard procedure. On all the other forms the mail comes up immediately when sent - I'm new, so if you're using a different arrangement over here I did not know about it. Also, it will be weekend over here soon and I'll be off the net till Monday - I just wanted to make sure my mail is received. Enjoy your weekend, Hennie ------------------------------ Date: Sat, 3 Aug 2002 17:54:24 -0500 To: "KR-Net" From: "Mark Jones" Subject: "Raise that hood please." Message-ID: <000e01c23b40$b6910be0$c5991f41@wi.rr.com> ------=_NextPart_000_000B_01C23B16.CD810820 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable This is the title of my new photo of the week page. Check the link on my = web page to see how I made a forward deck hood for rear instrument panel = and cockpit floor access. http://mywebpage.netscape.com/n886mj/homepage.html Mark Jones (N886MJ) Wales, WI USA=20 E-mail me at flykr2s@wi.rr.com Visit my KR-2S CorvAIRCRAFT web site at =20 http://mywebpage.netscape.com/n886mj/homepage.html ------=_NextPart_000_000B_01C23B16.CD810820-- ------------------------------ Date: Sat, 3 Aug 2002 21:04:07 -0500 To: "KR-Net" From: "Mark Jones" Subject: Waiting to fly. Message-ID: <001101c23b5b$37b70840$c5991f41@wi.rr.com> ------=_NextPart_000_000E_01C23B31.4E8D13E0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable I have added a new section on my web page under "Featured KR's". It is = called "Waiting to Fly" and Ron Vogt's KR-2S is the first one featured = there. "Waiting to Fly" means all one needs is for the FAA to inspect = and issue certificates. Mark Jones (N886MJ) Wales, WI USA=20 E-mail me at flykr2s@wi.rr.com Visit my KR-2S CorvAIRCRAFT web site at =20 http://mywebpage.netscape.com/n886mj/homepage.html ------=_NextPart_000_000E_01C23B31.4E8D13E0-- ------------------------------ Date: Sat, 3 Aug 2002 23:03:57 -0700 To: "KRnet" From: "terry marion ks" Subject: Re: KR> cookout Message-ID: <002c01c23b7c$e2e77bc0$35a060cc@r6t1n9> I,m having a cookout sat . night at Marion KS (43k) around 6:00 pm . TERRY CHIZEK ------------------------------ Date: Sat, 3 Aug 2002 23:51:58 -0500 To: "KR-Net" From: "Mark Jones" Subject: Canopy Cutting Message-ID: <002a01c23b72$ac9435e0$c5991f41@wi.rr.com> ------=_NextPart_000_0027_01C23B48.C2A87820 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Thanks to all who responded to the best method to cut a canopy. I just = walked in from the shop where I just completed cutting up my $470 = Dragonfly canopy. I am now truly committed to a gull wing design now!!! After debating on everyone's ideas, I popped a cutting wheel on my = Dremel and commenced cutting. Very easy and very smooth...no cracks and = virtually no ridge from melting Plexiglas. It is also amazing how = quickly one can cut a canopy door with a Dremel. I did go through about = six cutting wheels. I used the very thin ones and they cut great, just = kept breaking them. Mark Jones (N886MJ) Wales, WI USA=20 E-mail me at flykr2s@wi.rr.com Visit my KR-2S CorvAIRCRAFT web site at =20 http://mywebpage.netscape.com/n886mj/homepage.html ------=_NextPart_000_0027_01C23B48.C2A87820-- ------------------------------ Date: Fri, 2 Aug 2002 00:30:03 -0500 To: "'krnet@mailinglists.org'" From: "van Rooyen, Hennie(SF02)" Subject: Suggestion for a wing fold mechanism Hi all, Here's my idea for a wing fold mechanism for the KR series. I hope it is understandable as this is the best I could do with text only. Step 1. Make the bracket below and fasten over the existing inboard forward spar wing attach brakets. Use the same bolts if you can. This bracket and hole wil protrude out of the top section of the wing. Not to worry, you'll fair this nicely with a small teardrop shape using foam and resin. ADD THIS BRACKET OVER THE EXISTING BRAKETS, ON BOTH SIDES OF THE FWD SPAR CAP I I V _ _ _ _ 0 _ WING FOLD_UP HINGE POINT, FWD SPAR ONLY - NOT USED AS AN ATTACH FITTING! I I -------------------I---------------I-----------I -------------------I---------------I-----------I----------- I I I I I I I 0 I TOP WAF I I I I -------------------I---------------I-----------I----------- I I I WING FRONT SPAR TOP I (INNER SPAR) I I I I I I I I I -------------------I---------------I-----------I----------- I I I I I I I 0 I BOTTOM WAF I I I I -------------------I---------------I-----------I----------- WING FRONT SPAR BOTTOM I ----------------------------------------------- Step 2. Make this L shaped bracket below and fasten over the existing outboard forward spar top wing attach brakets. Use the same bolts if you can. Make sure to dril a hole in line with the existing wing attach bolt as this is stil used to fasten the wing. ADD THIS BRACKET OVER THE EXISTING TOP OUTER SPAR TOP WAF ON BOTH SIDES _ _ _ _ 0 _ I I ---------------------------------------------------------------------------- --- I I I EXISTING OUTER FWD SPAR TOP WAF I I--------------------------------------------------------------------------- --------- I I I I I 0 MAKE SURE OF NEW HOLE I OVER AND IN LINE WITH EXISTING HOLE FOR NORMAL ATTACH BOLT I I I I--------------------------------------------------------------------------- ------------------------- I I OUTER WING FRONT SPAR TOP I I I I ---------------------------------------------------------- I I I 0 I BOTTOM WAF I I ---------------------------------------------------------- I ----------------------------------------------- Step 3. Now alling everything and put bolts through the normal attach holes. Step 4. Now permanently put bolts through the brackets on both sides of the spar cap protruding through the top of the wing. Do not tighten too much as this is going to be your permanent hinge Step 5. Now make a teardrob shaped permanent fairing around the stuff sticking out the top of the wing. When ready to use, simply loosen all eight wing attach bolts and swing the wing up and against the canopy using the swivel point sticking through the top of the wing. Viola, no more painful wing detach and asssembly efferts. I hope you understand the above. Regards, Hennie ------------------------------ Date: Thu, 1 Aug 2002 21:44:58 -0500 To: "'krnet@mailinglists.org'" From: "van Rooyen, Hennie(SF02)" Subject: KR2 heavier engine support idea Hi all, I had the following idea - If it's been suggested before, I apologise as I'm unaware of it. If you are planning to use one of the heavier engines for your KR, might it not be an good idea to run a tube from the front of the forward spar along the fuselage on each side to the back of your top wirewall engine mount? I'm convinced that it will provide added strenght under high positive g manouvers. I am NOT suggesting that the existing attach method does not do the job properly, but doing it this way will certainly make me feel safer without a significant weight penalty. Just an idea though if I may express it here... Regards, Hennie ------------------------------ Date: Thu, 1 Aug 2002 21:01:03 -0500 To: "'krnet@mailinglists.org'" From: "van Rooyen, Hennie(SF02)" Subject: FW: KR> The AS5046 airfoil Hi Larry, 1. "From where will you get the *other* 8hp? A 503 is only good for 52, isn't it?" No Larry, actually 53. By removing the fan and force cooling air from the prop intake like any other aircraft. I've done it before, it works! I'll also fit bigger carbs and install tune pipes (long ones) under the belly. The biggest Hp limitation on a two stroke is the same as any other engine - HEAT. By forcing air through the engine by much higher than the normal 40mph microlight speed, would cause it to run cooler and it should easily cope with only another 8Hp! 2. "And at cruise, closer to 39-40?" Now Larry, how can you make a statement like this? Please look at your specs for the first KR2 with 60Hp. 60Hp is 60Hp, no matter where it comes from. Plus mine will be lighter, less angle of attack in flight will cause less drag and using a superior airfoil...I'm sorry, this statement makes no sense to me at all... 3."Hmmm... I'm guessing these are thirsty... 180hp 2stroke? yup, probably pretty thirsty." A two stroke is thirsty by nature - however, in all my microlight flying the results using 25litres of fuel: a. One up - 2 hours b. Two up - 1,5 hours. This does not compare too bad with the VW's figures. I have no idea what the Arrow engine will consume, but then I take it for granted that the Corvair also uses a lot more than the VW. Speed comes with a price tag! 4. "Uhm... an F-16 AND a C-150 demonstrate significant differences with 2up/full Fuel conditions, yet yours will not?? This will be interesting." Larry, I'm talking about the cg problems that most KR2 flyers are experiencing. I've read a few posts even here where it was stated that the KR2 couldn't be trimmed for level flight flying solo. The cg change has been the biggest complaint on the KR2 over all these years, even more so than the sensitive elevator! I've saolved that on my aircraft. 5. "Yes, wonder why that fuse tapers? Hmmm. wonder why EVERY tailcone isn't Square at the bottom? Hmmm.. wonder why each and every >200mph plane out there has a rounded tailcone... hmmmm.... oh, except the Mustang2/Thorp t-18, 200hp/200mph... you might wanna check into some aero studies on wing root fairing and fuselage boundary layer." Larry, you'll not gain more than 3mph or so from this effect. And then just about everyone is willing to throw away that 3mph by widening the fuselage for marginal increase in comfort only. You should come and sit in mine - I promise you'll change your mind on the spot! So, I may loose 6mph or so, which the new airfoil plus slight upwards full span flaps will give back to me. 6. "Though inspection is easier... wonder why EVERY high performance plane doesn't use tubes?? Check into flutter failure modes... Re-examine your item" Now Larry, how can a balanced surface attached to a tube with no cable or any other slack be more prone to flutter? 7. "Pilatus-type split flaps (which have holes in them, BTW) are little more than air brakes. They produce very little in the way of useful low speed lift and are considered inefficient for the complexity. Drag=Lift. The trick is to get Lift in a unified and useful direction. Hence, flaps. There is a very big difference between decreasing lift and decreasing stall speed." No comment - I saw a sketch that shows the layout I've mentioned and it seems like a nice way to go for me. I don't want too much drag by deploying the first part of the flap range, as I want to use it for take-offs also. 8. "You might remember you're going from about 3#/sq.ft. wing loading to around 6 or more. Unless, with your longer wings, you're increasing the wing area, then your ride gets worse and your handling more microlight-like. "Coming down like a parachute" is no accommplishment -- 'landing like a rocking chair' IS. " Larry, if you were with me in my emergency landings in microlights, you would have understood better. By using spoilers, I can choose a landing spot and put it down there for sure without overshooting. I once landed with a hanglider pilot on my passenger seat in a mountain with lots of boulders and other obstacles. I put it down without bending a tube. Was it not for the spoilers, I would have been dead. 9."[U]nsure or the strength of this arrangement"?? "So I built new spars"?? Uhhh.... this has the 'kindergarteners with handguns' sort of feel to it, sorry. Learn to run the numbers. Learn what they mean. KNOW what your vehicle's engineered limits (all of them) are. Are you setting up a stress riser? Do you know what that is? Before you "design" anything, you might want to brush up a bit on some of these lessons (learned the hard way throughout history). Just a though " No Larry, I find that you are doing your best to be nasty - all your previous statements are invalid yet you say I'm from the kindergarten. I will contact you when this aircraft flies and then I'll see if you have the courage to apologies... 10. "otsa ruck :-) Let us know how it goes and if we can help." Well Larry, to tell you the truth, I've made it thus far without any help, why should I cry for it now. This is the worst introduction I've had to ANY forum, THANKS! Maybe this is a bless me club. I see radical changes being made to most KR's on the net. Do you have the same attitude towards all of them or is it just me. Besides, you're too late. My aircraft is about 50% complete, I'm not talking about "schemes" here or do you think I like to waste my cheap time by building just to keep myself busy? It will fly in the not to distant future and if I succeed (I'm confident I will), I hope I'll get an apology. The manufacturer of the extremely popular Lancair range used to be a KR builder once. Did you treat him with the same contempt? I'm not looking for a fight. Just as Mark Langford expressed his idea of a more successful version of the KR (and I'm sure Mark will achieve EVERY single thing that he's after), so am I also entitled to my opinion of "experimenting" with this design? I'll continue to post here regardless of your attitude, as I did not do anything wrong as far as I'm aware. You are welcome to reject my ideas just as much as I thought that I was welcome to share them here. I've seen turbine powered Kr's, Continental powered KR's - none of these were EVER planned or allowed for by Ken Rand, yet people with initiative did it and now it's a common thing. So it's O.k. to keep on increasing the empty weight of this aircraft against the designer's intention. I'm going the opposite way, back to the original empty designed weight (might even be less) and I'm been torn apart for doing so. Strange, strange world indeed... Regards, Hennie -----Original Message----- From: Schurr, Larry [mailto:LSchurr@bellhelicopter.textron.com] Sent: Thursday, August 01, 2002 2:42 PM To: 'krnet@mailinglists.org' Subject: RE: KR> The AS5046 airfoil Hennie, No one can fault your spirit, that's for sure :-) In reading your treatise on your upcoming plane, I couldn't help but wonder about some questions, not necessarily issues, but some little 'red lights' in my nay-sayer head -- I'm such a terrible cynic! -- and thought I'd chime in. > So I re-designed everything by: > > 5. The tail feathers have been increased for better control > and low speed > handling. > > 6. Coming from a microlighting background, I know where to > find 60 Hp at > less than half the weight of the VW, so I'll use a proper 2 > stroke like the > 503 Rotax From where will you get the *other* 8hp? A 503 is only good for 52, isn't it? And at cruise, closer to 39-40? >until my finances allow something like the 30Hp Hirth or 6 > cylinder 180Hp Arrow two stroke engines. Having many hours in > the air with > two strokes gives me the total confidence to do this. Hmmm... I'm guessing these are thirsty... 180hp 2stroke? yup, probably pretty thirsty. > - my aircraft should fly the > same with one > or two aboard and wheather no fuel or full fuel. Uhm... an F-16 AND a C-150 demonstrate significant differences with 2up/full fuel conditions, yet yours will not?? This will be interesting. > > 9. I see no benefit in tapering the fuselage at the bottom, > so mine is wider > than the KR and the same width top and bottom. Having located > the seats > forward puts the shoulders at the widest part of the airframe > and my seating > arrangement is extremely comfortable with two aboard. Yes, wonder why that fuse tapers? Hmmm... wonder why EVERY tailcone isn't square at the bottom? Hmmm.. wonder why each and every >200mph plane out there has a rounded tailcone... hmmmm.... oh, except the Mustang2/Thorp t-18, 200hp/200mph... you might wanna check into some aero studies on wing root fairing and fuselage boundary layer. Though true, a flat bottom CAN be shown to produce better ground effect that can *contribute* to lower landing speed, it can also reduce your numbers at cruise with increased boundary layer drag. > > 10. I've used tube push pull control throughout like in most > microlights - > much easier to construct and a lot safer and less complex > than any cable > arrangement. The ONLY easily accessible parts to be inspected on every > preflight are the clearly visible bolts at each end. Though inspection is easier... wonder why EVERY high performance plane doesn't use tubes?? Check into flutter failure modes... Re-examine your item 5. above. Increasing area? >200mph? Be sure to take the necessary steps to prevent flutter. > 15. I'll use the new airfoil with full span flaps, even on > the inboard side. > The flaps will be like the PC Pilatus, which is hinged at the > bottom wing > skin with a curve at the top like yours. Thus there'll be no > gap and by > deploying them, the bottom wing area stays the same but the > top area is > increased making the total wing area larger helping with more > lift for both > take-offs and landings. Landing at 25 - 30 mph should get rid > of most of the > floating in any case. Pilatus-type split flaps (which have holes in them, BTW) are little more than air brakes. They produce very little in the way of useful low speed lift and are considered inefficient for the complexity. Drag=Lift. The trick is to get Lift in a unified and useful direction. Hence, flaps. There is a very big difference between decreasing lift and decreasing stall speed. > > 16. I'll use spoilers on the outboard wings for both roll and decent > control. My life was saved on more than one occasion on > microlights by this > facility by being able to deploy both spoilers > simultaneously, killing a lot > of lift in this way. Once it got me out of cloud suck and in > landings, I > could come down like a parachute. By letting them retract > just above the > ground I could then flare and do a normal landing. Thus, > using spoilers in > this way lets you absolutely control your descent and you can put the > aircraft down anywhere you want! You might remember you're going from about 3#/sq.ft. wingloading to around 6 or more. Unless, with your longer wings, you're increasing the wing area, then your ride gets worse and your handling more microlight-like. "Coming down like a parachute" is no accommplishment -- 'landing like a rocking chair' IS. > > 17. Initially I was going to use the GAW-1 airfoil. I was > going to attach > the wings right at the fuselage so that the brackets of the > outer wings > actually protrude into the fuselage. The wing attach bolt > would then be > inside the fuselage where they could be easily reached. > Because I'm using > longer wings and unsure of the strength of this arrangement, > I came up with > another idea in which the outboard wings simply fold up at > the joint with > only minor modifications to one of the upper main WAFs. So I > built new spars > like the KR and this is the way I'll go. "[U]nsure or the strength of this arrangement"?? "So I built new spars"?? Uhhh.... this has the 'kindergarteners with handguns' sort of feel to it, sorry. Learn to run the numbers. Learn what they mean. KNOW what your vehicle's engineered limits (all of them) are. Are you setting up a stress riser? Do you know what that is? Before you "design" anything, you might want to brush up a bit on some of these lessons (learned the hard way throughout history). Just a thought. > > I made several other changes, but all in all I'm convinced > I'll get what I'm > after and I hope to be flying before this Christmas. Rotsa ruck :-) Let us know how it goes and if we can help. Larry > --------------------------------------------------------------------- To post to the list, email: krnet@mailinglists.org , NOT "reply all" To UNsubscribe, e-mail: krnet-unsubscribe@mailinglists.org For additional commands, e-mail: krnet-help@mailinglists.org See the KRNet archives at http://www.maddyhome.com/krsrch/index.jsp or http://www.bouyea.net/ for the Word files ------------------------------ Date: Fri, 2 Aug 2002 04:05:45 -0500 To: "Schurr, Larry" , "'krnet@mailinglists.org'" From: "van Rooyen, Hennie(SF02)" Subject: RE: KR> The AS5046 airfoil Hi Larry, Maybe I've read things in your reply that you did not intend as sarcasm - for that reason, please ignore my previous post as my feelings were hurt. I'm still not sure if you're trying to help or be sarcastic, but for the benefit of the doubt here's a better version: 1. "From where will you get the *other* 8hp? A 503 is only good for 52, isn't it?" No Larry, actually 53. By removing the fan and force cooling air from the prop intake like any other aircraft. I've done it before, it works! I'll also fit bigger carbs and install tune pipes (long ones) under the belly. The biggest Hp limitation on a two stroke is the same as any other engine - HEAT. By forcing air through the engine by much higher than the normal 40mph microlight speed, would cause it to run cooler and it should easily cope with only another 8Hp! 2. "And at cruise, closer to 39-40?" Now Larry, how can you make a statement like this? Please look at your specs for the first KR2 with 60Hp. 60Hp is 60Hp, no matter where it comes from. Plus mine will be lighter, less angle of attack in flight will cause less drag and using a superior airfoil...I'm sorry, this statement makes no sense to me at all...Why would my engine deliver any less Hp in cruise than a VW without a turbo. Then the VW also produces 39-40 Hp in cruise and it works fine for a light weight KR, so it should work fine for me also. 3."Hmmm... I'm guessing these are thirsty... 180hp 2stroke? yup, probably pretty thirsty." A two stroke is thirsty by nature - however, in all my microlight flying the results using 25litres of fuel: a. One up - 2 hours b. Two up - 1,5 hours. This does not compare too bad with the VW's figures. I have no idea what the Arrow engine will consume, but then I take it for granted that the Corvair also uses a lot more than the VW. Speed comes with a price tag! 4. "Uhm... an F-16 AND a C-150 demonstrate significant differences with 2up/full Fuel conditions, yet yours will not?? This will be interesting." Larry, I'm talking about the cg problems that most KR2 flyers are experiencing. I've read a few posts even here where it was stated that the KR2 couldn't be trimmed for level flight flying solo. The cg change has been the biggest complaint on the KR2 over all these years, even more so than the sensitive elevator! I've saolved that on my aircraft. 5. "Yes, wonder why that fuse tapers? Hmmm. wonder why EVERY tailcone isn't Square at the bottom? Hmmm.. wonder why each and every >200mph plane out there has a rounded tailcone... hmmmm.... oh, except the Mustang2/Thorp t-18, 200hp/200mph... you might wanna check into some aero studies on wing root fairing and fuselage boundary layer." Larry, you'll not gain more than 3mph or so from this effect. And then just about everyone is willing to throw away that 3mph by widening the fuselage for marginal increase in comfort only. You should come and sit in mine - I promise you'll change your mind on the spot! So, I may loose 6mph or so, which the new airfoil plus slight upwards full span flaps will give back to me. 6. "Though inspection is easier... wonder why EVERY high performance plane doesn't use tubes?? Check into flutter failure modes... Re-examine your item" Now Larry, how can a balanced surface attached to a tube with no cable or any other slack be more prone to flutter? Honest, I'm not trying to be nasty here, but this does not make too much sense. Not that I expect to reach 200 mph with my initial engine installation, but it's nice to know I'm safe for later power upgrades. 7. "Pilatus-type split flaps (which have holes in them, BTW) are little more than air brakes. They produce very little in the way of useful low speed lift and are considered inefficient for the complexity. Drag=Lift. The trick is to get Lift in a unified and useful direction. Hence, flaps. There is a very big difference between decreasing lift and decreasing stall speed." No comment - I saw a sketch that shows the layout I've mentioned and it seems like a nice way to go for me. I don't want too much drag by deploying the first part of the flap range, as I want to use it for take-offs also. On all production aircraft (or almost all) the normal thing is to use one notch of flaps for take-off, thus flaps must be able to generate lift without too much drag during the first few degrees of travel. 8. "You might remember you're going from about 3#/sq.ft. wing loading to around 6 or more. Unless, with your longer wings, you're increasing the wing area, then your ride gets worse and your handling more microlight-like. "Coming down like a parachute" is no accommplishment -- 'landing like a rocking chair' IS. " Larry, if you were with me in my emergency landings in microlights, you would have understood better. By using spoilers, I can choose a landing spot and put it down there for sure without overshooting. I once landed with a hanglider pilot on my passenger seat in a mountain with lots of boulders and other obstacles. I put it down without bending a tube. Was it not for the spoilers, I would have been dead. 9."[U]nsure or the strength of this arrangement"?? "So I built new spars"?? Uhhh.... this has the 'kindergarteners with handguns' sort of feel to it, sorry. Learn to run the numbers. Learn what they mean. KNOW what your vehicle's engineered limits (all of them) are. Are you setting up a stress riser? Do you know what that is? Before you "design" anything, you might want to brush up a bit on some of these lessons (learned the hard way throughout history). Just a though " Larry, my post reads that I've slightly INCREASED the dimensions on all my wooden parts. Plus, using a GAW-1 airfoil would allow for quite a thick (deep)spar. As you know the strenght of the spar goes up with the square of the height, so I KNOW I'm safe in all I did. Nobody (as to my knowledge) beafed up the longeron sizes by stretching the fuselage to the KR2S or even accepting the bigger engines. I know that there is a SLIGHT alteration on the wood structure behind the firewall, but nothing major. Also, builders are increasing the standard wing lenght by up to four feet without spars or beefing up the existing spars! And that with those heavy engines. I'm sure I'm safe in whatever I've done. Look at the lenght of the KR1B wing! I'm not even going close to that but more than likely 24 ft or so as that's the lenght of my current spars. I honestly see no kindergarten stuff here... 10. "otsa ruck :-) Let us know how it goes and if we can help." Larry, I dunno if "otsa ruck" means lots of luck - if it does then thank you very much for the help offered! I see radical changes being made to most KR's on the net. I'm not looking for a fight. Just as Mark Langford expressed his idea of a more successful version of the KR (and I'm sure Mark will achieve EVERY single thing that he's after), so am I also entitled to my opinion of "experimenting" with this design? You are welcome to reject my ideas just as much as I thought that I was welcome to share them here. I've seen turbine powered Kr's, Continental powered KR's - none of these were EVER planned or allowed for by Ken Rand, yet people with initiative did it and now it's a common thing. So it's O.k. to keep on increasing the empty weight of this aircraft against the designer's intention. I'm going the opposite way, back to the original empty designed weight (might even be less) and I'm being doubted doing so. I'm sure Ken would be pleased if this all works out as his main idea was to keep it as light and simple as possible. Please accept my humble apologies once again if you did not try to be sarcastic but only tried to help. Regards, Hennie -----Original Message----- From: Schurr, Larry [mailto:LSchurr@bellhelicopter.textron.com] Sent: Thursday, August 01, 2002 2:42 PM To: 'krnet@mailinglists.org' Subject: RE: KR> The AS5046 airfoil Hennie, No one can fault your spirit, that's for sure :-) In reading your treatise on your upcoming plane, I couldn't help but wonder about some questions, not necessarily issues, but some little 'red lights' in my nay-sayer head -- I'm such a terrible cynic! -- and thought I'd chime in. > So I re-designed everything by: > > 5. The tail feathers have been increased for better control > and low speed > handling. > > 6. Coming from a microlighting background, I know where to > find 60 Hp at > less than half the weight of the VW, so I'll use a proper 2 > stroke like the > 503 Rotax From where will you get the *other* 8hp? A 503 is only good for 52, isn't it? And at cruise, closer to 39-40? >until my finances allow something like the 30Hp Hirth or 6 > cylinder 180Hp Arrow two stroke engines. Having many hours in > the air with > two strokes gives me the total confidence to do this. Hmmm... I'm guessing these are thirsty... 180hp 2stroke? yup, probably pretty thirsty. > - my aircraft should fly the > same with one > or two aboard and wheather no fuel or full fuel. Uhm... an F-16 AND a C-150 demonstrate significant differences with 2up/full fuel conditions, yet yours will not?? This will be interesting. > > 9. I see no benefit in tapering the fuselage at the bottom, > so mine is wider > than the KR and the same width top and bottom. Having located > the seats > forward puts the shoulders at the widest part of the airframe > and my seating > arrangement is extremely comfortable with two aboard. Yes, wonder why that fuse tapers? Hmmm... wonder why EVERY tailcone isn't square at the bottom? Hmmm.. wonder why each and every >200mph plane out there has a rounded tailcone... hmmmm.... oh, except the Mustang2/Thorp t-18, 200hp/200mph... you might wanna check into some aero studies on wing root fairing and fuselage boundary layer. Though true, a flat bottom CAN be shown to produce better ground effect that can *contribute* to lower landing speed, it can also reduce your numbers at cruise with increased boundary layer drag. > > 10. I've used tube push pull control throughout like in most > microlights - > much easier to construct and a lot safer and less complex > than any cable > arrangement. The ONLY easily accessible parts to be inspected on every > preflight are the clearly visible bolts at each end. Though inspection is easier... wonder why EVERY high performance plane doesn't use tubes?? Check into flutter failure modes... Re-examine your item 5. above. Increasing area? >200mph? Be sure to take the necessary steps to prevent flutter. > 15. I'll use the new airfoil with full span flaps, even on > the inboard side. > The flaps will be like the PC Pilatus, which is hinged at the > bottom wing > skin with a curve at the top like yours. Thus there'll be no > gap and by > deploying them, the bottom wing area stays the same but the > top area is > increased making the total wing area larger helping with more > lift for both > take-offs and landings. Landing at 25 - 30 mph should get rid > of most of the > floating in any case. Pilatus-type split flaps (which have holes in them, BTW) are little more than air brakes. They produce very little in the way of useful low speed lift and are considered inefficient for the complexity. Drag=Lift. The trick is to get Lift in a unified and useful direction. Hence, flaps. There is a very big difference between decreasing lift and decreasing stall speed. > > 16. I'll use spoilers on the outboard wings for both roll and decent > control. My life was saved on more than one occasion on > microlights by this > facility by being able to deploy both spoilers > simultaneously, killing a lot > of lift in this way. Once it got me out of cloud suck and in > landings, I > could come down like a parachute. By letting them retract > just above the > ground I could then flare and do a normal landing. Thus, > using spoilers in > this way lets you absolutely control your descent and you can put the > aircraft down anywhere you want! You might remember you're going from about 3#/sq.ft. wingloading to around 6 or more. Unless, with your longer wings, you're increasing the wing area, then your ride gets worse and your handling more microlight-like. "Coming down like a parachute" is no accommplishment -- 'landing like a rocking chair' IS. > > 17. Initially I was going to use the GAW-1 airfoil. I was > going to attach > the wings right at the fuselage so that the brackets of the > outer wings > actually protrude into the fuselage. The wing attach bolt > would then be > inside the fuselage where they could be easily reached. > Because I'm using > longer wings and unsure of the strength of this arrangement, > I came up with > another idea in which the outboard wings simply fold up at > the joint with > only minor modifications to one of the upper main WAFs. So I > built new spars > like the KR and this is the way I'll go. "[U]nsure or the strength of this arrangement"?? "So I built new spars"?? Uhhh.... this has the 'kindergarteners with handguns' sort of feel to it, sorry. Learn to run the numbers. Learn what they mean. KNOW what your vehicle's engineered limits (all of them) are. Are you setting up a stress riser? Do you know what that is? Before you "design" anything, you might want to brush up a bit on some of these lessons (learned the hard way throughout history). Just a thought. > > I made several other changes, but all in all I'm convinced > I'll get what I'm > after and I hope to be flying before this Christmas. Rotsa ruck :-) Let us know how it goes and if we can help. Larry > --------------------------------------------------------------------- To post to the list, email: krnet@mailinglists.org , NOT "reply all" To UNsubscribe, e-mail: krnet-unsubscribe@mailinglists.org For additional commands, e-mail: krnet-help@mailinglists.org See the KRNet archives at http://www.maddyhome.com/krsrch/index.jsp or http://www.bouyea.net/ for the Word files ------------------------------ Date: Fri, 2 Aug 2002 03:42:38 -0500 To: "'krnet@mailinglists.org'" From: "van Rooyen, Hennie(SF02)" Subject: FW: KR> The AS5046 airfoil and apology -----Original Message----- From: van Rooyen, Hennie(SF02) Sent: Friday, August 02, 2002 4:01 AM To: 'krnet@mailinglists.org' Subject: FW: KR> The AS5046 airfoil Hi Larry, Maybe I've read things in your reply that you did not intend as sarcasm - for that reason, please ignore my previous post as my feelings were hurt. I'm still not sure if you're trying to help or be sarcastic, but for the benefit of the doubt here's a better version: 1. "From where will you get the *other* 8hp? A 503 is only good for 52, isn't it?" No Larry, actually 53. By removing the fan and force cooling air from the prop intake like any other aircraft. I've done it before, it works! I'll also fit bigger carbs and install tune pipes (long ones) under the belly. The biggest Hp limitation on a two stroke is the same as any other engine - HEAT. By forcing air through the engine by much higher than the normal 40mph microlight speed, would cause it to run cooler and it should easily cope with only another 8Hp! 2. "And at cruise, closer to 39-40?" Now Larry, how can you make a statement like this? Please look at your specs for the first KR2 with 60Hp. 60Hp is 60Hp, no matter where it comes from. Plus mine will be lighter, less angle of attack in flight will cause less drag and using a superior airfoil...I'm sorry, this statement makes no sense to me at all...Why would my engine deliver any less Hp in cruise than a VW without a turbo. Then the VW also produces 39-40 Hp in cruise and it works fine for a light weight KR, so it should work fine for me also. 3."Hmmm... I'm guessing these are thirsty... 180hp 2stroke? yup, probably pretty thirsty." A two stroke is thirsty by nature - however, in all my microlight flying the results using 25litres of fuel: a. One up - 2 hours b. Two up - 1,5 hours. This does not compare too bad with the VW's figures. I have no idea what the Arrow engine will consume, but then I take it for granted that the Corvair also uses a lot more than the VW. Speed comes with a price tag! 4. "Uhm... an F-16 AND a C-150 demonstrate significant differences with 2up/full Fuel conditions, yet yours will not?? This will be interesting." Larry, I'm talking about the cg problems that most KR2 flyers are experiencing. I've read a few posts even here where it was stated that the KR2 couldn't be trimmed for level flight flying solo. The cg change has been the biggest complaint on the KR2 over all these years, even more so than the sensitive elevator! I've saolved that on my aircraft. 5. "Yes, wonder why that fuse tapers? Hmmm. wonder why EVERY tailcone isn't Square at the bottom? Hmmm.. wonder why each and every >200mph plane out there has a rounded tailcone... hmmmm.... oh, except the Mustang2/Thorp t-18, 200hp/200mph... you might wanna check into some aero studies on wing root fairing and fuselage boundary layer." Larry, you'll not gain more than 3mph or so from this effect. And then just about everyone is willing to throw away that 3mph by widening the fuselage for marginal increase in comfort only. You should come and sit in mine - I promise you'll change your mind on the spot! So, I may loose 6mph or so, which the new airfoil plus slight upwards full span flaps will give back to me. 6. "Though inspection is easier... wonder why EVERY high performance plane doesn't use tubes?? Check into flutter failure modes... Re-examine your item" Now Larry, how can a balanced surface attached to a tube with no cable or any other slack be more prone to flutter? Honest, I'm not trying to be nasty here, but this does not make too much sense. Not that I expect to reach 200 mph with my initial engine installation, but it's nice to know I'm safe for later power upgrades. 7. "Pilatus-type split flaps (which have holes in them, BTW) are little more than air brakes. They produce very little in the way of useful low speed lift and are considered inefficient for the complexity. Drag=Lift. The trick is to get Lift in a unified and useful direction. Hence, flaps. There is a very big difference between decreasing lift and decreasing stall speed." No comment - I saw a sketch that shows the layout I've mentioned and it seems like a nice way to go for me. I don't want too much drag by deploying the first part of the flap range, as I want to use it for take-offs also. On all production aircraft (or almost all) the normal thing is to use one notch of flaps for take-off, thus flaps must be able to generate lift without too much drag during the first few degrees of travel. 8. "You might remember you're going from about 3#/sq.ft. wing loading to around 6 or more. Unless, with your longer wings, you're increasing the wing area, then your ride gets worse and your handling more microlight-like. "Coming down like a parachute" is no accommplishment -- 'landing like a rocking chair' IS. " Larry, if you were with me in my emergency landings in microlights, you would have understood better. By using spoilers, I can choose a landing spot and put it down there for sure without overshooting. I once landed with a hanglider pilot on my passenger seat in a mountain with lots of boulders and other obstacles. I put it down without bending a tube. Was it not for the spoilers, I would have been dead. 9."[U]nsure or the strength of this arrangement"?? "So I built new spars"?? Uhhh.... this has the 'kindergarteners with handguns' sort of feel to it, sorry. Learn to run the numbers. Learn what they mean. KNOW what your vehicle's engineered limits (all of them) are. Are you setting up a stress riser? Do you know what that is? Before you "design" anything, you might want to brush up a bit on some of these lessons (learned the hard way throughout history). Just a though " Larry, my post reads that I've slightly INCREASED the dimensions on all my wooden parts. Plus, using a GAW-1 airfoil would allow for quite a thick (deep)spar. As you know the strenght of the spar goes up with the square of the height, so I KNOW I'm safe in all I did. Nobody (as to my knowledge) beafed up the longeron sizes by stretching the fuselage to the KR2S or even accepting the bigger engines. I know that there is a SLIGHT alteration on the wood structure behind the firewall, but nothing major. Also, builders are increasing the standard wing lenght by up to four feet without spars or beefing up the existing spars! And that with those heavy engines. I'm sure I'm safe in whatever I've done. Look at the lenght of the KR1B wing! I'm not even going close to that but more than likely 24 ft or so as that's the lenght of my current spars. I honestly see no kindergarten stuff here... 10. "otsa ruck :-) Let us know how it goes and if we can help." Larry, I dunno if "otsa ruck" means lots of luck - if it does then thank you very much for the help offered! I see radical changes being made to most KR's on the net. I'm not looking for a fight. Just as Mark Langford expressed his idea of a more successful version of the KR (and I'm sure Mark will achieve EVERY single thing that he's after), so am I also entitled to my opinion of "experimenting" with this design? You are welcome to reject my ideas just as much as I thought that I was welcome to share them here. I've seen turbine powered Kr's, Continental powered KR's - none of these were EVER planned or allowed for by Ken Rand, yet people with initiative did it and now it's a common thing. So it's O.k. to keep on increasing the empty weight of this aircraft against the designer's intention. I'm going the opposite way, back to the original empty designed weight (might even be less) and I'm being doubted doing so. I'm sure Ken would be pleased if this all works out as his main idea was to keep it as light and simple as possible. Please accept my humble apologies once again if you did not try to be sarcastic but only tried to help. Regards, Hennie -----Original Message----- From: Schurr, Larry [mailto:LSchurr@bellhelicopter.textron.com] Sent: Thursday, August 01, 2002 2:42 PM To: 'krnet@mailinglists.org' Subject: RE: KR> The AS5046 airfoil Hennie, No one can fault your spirit, that's for sure :-) In reading your treatise on your upcoming plane, I couldn't help but wonder about some questions, not necessarily issues, but some little 'red lights' in my nay-sayer head -- I'm such a terrible cynic! -- and thought I'd chime in. > So I re-designed everything by: > > 5. The tail feathers have been increased for better control > and low speed > handling. > > 6. Coming from a microlighting background, I know where to > find 60 Hp at > less than half the weight of the VW, so I'll use a proper 2 > stroke like the > 503 Rotax From where will you get the *other* 8hp? A 503 is only good for 52, isn't it? And at cruise, closer to 39-40? >until my finances allow something like the 30Hp Hirth or 6 > cylinder 180Hp Arrow two stroke engines. Having many hours in > the air with > two strokes gives me the total confidence to do this. Hmmm... I'm guessing these are thirsty... 180hp 2stroke? yup, probably pretty thirsty. > - my aircraft should fly the > same with one > or two aboard and wheather no fuel or full fuel. Uhm... an F-16 AND a C-150 demonstrate significant differences with 2up/full fuel conditions, yet yours will not?? This will be interesting. > > 9. I see no benefit in tapering the fuselage at the bottom, > so mine is wider > than the KR and the same width top and bottom. Having located > the seats > forward puts the shoulders at the widest part of the airframe > and my seating > arrangement is extremely comfortable with two aboard. Yes, wonder why that fuse tapers? Hmmm... wonder why EVERY tailcone isn't square at the bottom? Hmmm.. wonder why each and every >200mph plane out there has a rounded tailcone... hmmmm.... oh, except the Mustang2/Thorp t-18, 200hp/200mph... you might wanna check into some aero studies on wing root fairing and fuselage boundary layer. Though true, a flat bottom CAN be shown to produce better ground effect that can *contribute* to lower landing speed, it can also reduce your numbers at cruise with increased boundary layer drag. > > 10. I've used tube push pull control throughout like in most > microlights - > much easier to construct and a lot safer and less complex > than any cable > arrangement. The ONLY easily accessible parts to be inspected on every > preflight are the clearly visible bolts at each end. Though inspection is easier... wonder why EVERY high performance plane doesn't use tubes?? Check into flutter failure modes... Re-examine your item 5. above. Increasing area? >200mph? Be sure to take the necessary steps to prevent flutter. > 15. I'll use the new airfoil with full span flaps, even on > the inboard side. > The flaps will be like the PC Pilatus, which is hinged at the > bottom wing > skin with a curve at the top like yours. Thus there'll be no > gap and by > deploying them, the bottom wing area stays the same but the > top area is > increased making the total wing area larger helping with more > lift for both > take-offs and landings. Landing at 25 - 30 mph should get rid > of most of the > floating in any case. Pilatus-type split flaps (which have holes in them, BTW) are little more than air brakes. They produce very little in the way of useful low speed lift and are considered inefficient for the complexity. Drag=Lift. The trick is to get Lift in a unified and useful direction. Hence, flaps. There is a very big difference between decreasing lift and decreasing stall speed. > > 16. I'll use spoilers on the outboard wings for both roll and decent > control. My life was saved on more than one occasion on > microlights by this > facility by being able to deploy both spoilers > simultaneously, killing a lot > of lift in this way. Once it got me out of cloud suck and in > landings, I > could come down like a parachute. By letting them retract > just above the > ground I could then flare and do a normal landing. Thus, > using spoilers in > this way lets you absolutely control your descent and you can put the > aircraft down anywhere you want! You might remember you're going from about 3#/sq.ft. wingloading to around 6 or more. Unless, with your longer wings, you're increasing the wing area, then your ride gets worse and your handling more microlight-like. "Coming down like a parachute" is no accommplishment -- 'landing like a rocking chair' IS. > > 17. Initially I was going to use the GAW-1 airfoil. I was > going to attach > the wings right at the fuselage so that the brackets of the > outer wings > actually protrude into the fuselage. The wing attach bolt > would then be > inside the fuselage where they could be easily reached. > Because I'm using > longer wings and unsure of the strength of this arrangement, > I came up with > another idea in which the outboard wings simply fold up at > the joint with > only minor modifications to one of the upper main WAFs. So I > built new spars > like the KR and this is the way I'll go. "[U]nsure or the strength of this arrangement"?? "So I built new spars"?? Uhhh.... this has the 'kindergarteners with handguns' sort of feel to it, sorry. Learn to run the numbers. Learn what they mean. KNOW what your vehicle's engineered limits (all of them) are. Are you setting up a stress riser? Do you know what that is? Before you "design" anything, you might want to brush up a bit on some of these lessons (learned the hard way throughout history). Just a thought. > > I made several other changes, but all in all I'm convinced > I'll get what I'm > after and I hope to be flying before this Christmas. Rotsa ruck :-) Let us know how it goes and if we can help. Larry > --------------------------------------------------------------------- To post to the list, email: krnet@mailinglists.org , NOT "reply all" To UNsubscribe, e-mail: krnet-unsubscribe@mailinglists.org For additional commands, e-mail: krnet-help@mailinglists.org See the KRNet archives at http://www.maddyhome.com/krsrch/index.jsp or http://www.bouyea.net/ for the Word files ------------------------------ End of krnet Digest ***********************************