From: owner-krnet-l-digest@teleport.com[SMTP:owner-krnet-l-digest@teleport.com] Sent: Tuesday, January 13, 1998 1:20 AM To: krnet-l-digest@teleport.com Subject: krnet-l-digest V2 #11 krnet-l-digest Tuesday, January 13 1998 Volume 02 : Number 011 ---------------------------------------------------------------------- Date: Mon, 12 Jan 1998 17:04:36 -0600 From: "Mark Langford" Subject: Re: KR: NLF Thoughts Don Reid wrote: >There is no such thing as a free lunch, each airfoil is a collection of >problems and solutions. Each one is designed for one specific mission >in life and will not work well in all situations. That's exactly right. And this airfoil in particular wasn't designed for the light wing loading and lower Reynolds numbers characteristic of the KR series. That's why I'm waiting for the one that was specifically designed for US. Also, we've been asked to come up with a list of specific design goals to shoot for. I'd think that since we already have the proven RAF48 to cover the pilots who like to land slow and stall gently (don't we all!), the mission for the new one might be more biased toward lower drag and higher top end speed. Given the tools that'll be used to design this new airfoil, I think they'll be able to fine tune away the high pitching moments at whatever speed we'd like to cruise at. My wings are definitely "on hold" until then. Mark Langford, Huntsville, AL email at langford@hiwaay.net KR2S project construction at http://fly.hiwaay.net/~langford ------------------------------ Date: Mon, 12 Jan 1998 15:03:06 -0800 From: Ross Youngblood Subject: Re: KR: Inspection/Training Program Response KMcken7414 wrote: > > Great job on the KR updates. I am new here and would like to see if there are > any sites dedicated to the KR's. > > Thanks Keith > Jacksinville, FL. Keith, Here are some starters: http://www.fly-kr.com -- Rand Robinsons Site http://www.krnet.org/krnet_yearbook.htm (Members & Their websites) http://www.krnet.org/krnet_yearbook_text.htm (no pictures--faster) Unfortunatly, I am behind in updating this page, many of the members links from this page will have more sites I don't have listed. -- Regards Ross ------------------------------ Date: Mon, 12 Jan 1998 14:57:12 -0800 From: Ross Youngblood Subject: Re: KR: Engine Mount Support Ron Brown wrote: > Now, for my next question. Do the upper engine mount reinforcements run the > entire length of the upper sill, or are they just localized support? The > plans or prints don't seem clear on this point. > If this is a repeat question for the group, my apologies in advance. > Remember, I am a "newbie". > Thanks > Ron Brown > > rjbrown@tir.com > rjbrown4@juno.com Ron, I have heard one or two KR's (out of hundereds) where the upper engine mount X-member came loose and the engine plopped to the ground. Later KRNET traffic made me wonder if this was the story of why the re-enforcement was installed in the first place. You are correct on the vagueness of the plans. I think the major goal of this reinforcement is to distribute the stress from the engine mount to the 1/4" plywood shelf, and to also spread it along the length of the forward cross member. In my case the angle runs lengthwise from one mount to the other. I don't see any advantage to running the entire width of the firewall, unless you capture the fuselage sides somehow, this would require an additional 5/8" spruce block for the bolts to go through. A similar idea was suggested by my EAA technical counselor, as some other wooden homebults with narrow fuselages, have engine mount points that capture the sides of the fuselage. Boy... I've been babbling again. At any rate, I just told you what I did based on my interpertation of the plans. (Dont forget bolts to the 1/4" plywood shelf.) This is by no means a qualified answer, just my implementation. -- Ross ------------------------------ Date: Mon, 12 Jan 1998 15:11:27 -0800 From: Ross Youngblood Subject: Re: KR: Re: Richard Parker wrote: > > As I begin building my boat, I wonder if there has ever been any discussion > or thought to making and using fiberglass fuselage skins bonded to the > original spruce frame. I would think that the strength, weight etc would be > close to plywood if a good clean job was done on them removing all excess > resin. > > Any body ever consider it? > > Richard Parker > Jaffrey, NH Richard, I think this has been done, there was an old snail mail newsletter article about this. My only concern would be the ability for the glass/spruce bond to hold over time. The two materials have different expansion cofficients[sp?] but as our glass/spruce bond holds the wings together, perhaps I'm worried about nothing. It's just that lengthwise, there seems to be more opportunity for this to be a problem with the fuselage, than with the wings. (smaller spruce contact area, larger glass expansion area). -- Ross ------------------------------ Date: Mon, 12 Jan 1998 15:21:51 -0800 From: Ross Youngblood Subject: Re: KR: News-letters Michelle, You are in luck. The newsletter had fallen down for a bit, but Monte Miller (Past KR builder) picked up the editorship and is breathing new life into the mail newsletter. KR Newsletter 624 University DR Suite 199 Denton, TX 76201 Rates: $20.00/yr USA $25.00/yr Canada $30.00/yr Overseas This informaiton is also available online at: http://www.krnet.org/KRnewsletter.htm (or go to) http://www.krnet.org, and click on SnailMail Newsletter. - -- Ross Michele Bucceri wrote: > > My apolgies in advance if my question is trivial. > > I've read many times on KRNet about some news-letters. > How can I get them? Is it automatic when you buy the plans, or should I > register somewhere? > > By the way, there is somebody out-there that have some unused set of KR2 > / KR2S plans to sell? > > Cheers, > Michele > -- > MBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMB > Michele Bucceri > E-mail: mailto:michele.bucceri@italtel.it > MBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMB ------------------------------ Date: Mon, 12 Jan 1998 17:35:16 -0500 From: "Jerry and Sandy Weiland" Subject: Re: KR: News-letters Dear Ross, As much as I enjoy reading all the mail that goes between KR people, I'm sorry but must ask to be removed from the mailing list. I'm getting 15 -30 emails a day and it's just too much. When I originally got on the list, there was an address and message to remove myself but unfortunately, I lost it. If you can take me off, please do, if not please send instructions and I'll do it. Yours, Jerry Weiland - ---------- > From: Ross Youngblood > To: KRNET > Subject: Re: KR: News-letters > Date: Monday, January 12, 1998 6:21 PM > > Michelle, > > You are in luck. The newsletter had fallen down for a bit, but > Monte Miller (Past KR builder) picked up the editorship and is > breathing new life into the mail newsletter. > > > > KR Newsletter > 624 University DR > Suite 199 > Denton, TX > 76201 > > Rates: > $20.00/yr USA > $25.00/yr Canada > $30.00/yr Overseas > > This informaiton is also available online at: > > http://www.krnet.org/KRnewsletter.htm > > (or go to) http://www.krnet.org, and click on SnailMail Newsletter. > > -- Ross > > Michele Bucceri wrote: > > > > My apolgies in advance if my question is trivial. > > > > I've read many times on KRNet about some news-letters. > > How can I get them? Is it automatic when you buy the plans, or should I > > register somewhere? > > > > By the way, there is somebody out-there that have some unused set of KR2 > > / KR2S plans to sell? > > > > Cheers, > > Michele > > -- > > MBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMB > > Michele Bucceri > > E-mail: mailto:michele.bucceri@italtel.it > > MBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMB ------------------------------ Date: Mon, 12 Jan 1998 15:35:16 -0800 From: Ross Youngblood Subject: KR: Re:FLOX your teeth & Micro management KMcken7414 wrote: > > I have a question. What is flox, and how is it done? Everything I know about FLOX: FLOX is covered pretty well in the KR plans. It is a mixture of epoxy and cotton FLOCK which you buy from our friends at Wicks Aircraft or Aircraft Spruce. Mix it up till it is wetter than peanut butter, and you can make quite a mess, but then you can stick anything to anything. When you are done, you can have hours of enjoyment sanding this rough stuff into place. FLOX is STRUCTURAL, Micro-slurry is NOT. Common uses for FLOX are: * Strengthing trailing edges of flight surfaces (covered in plans). * FLOXing stuff in place. For example, suppose you want to attach a metal bracket to a fiberglass piece you have, if you rough it up, and drill enough holes in it, flox will attach it to just about anything. This is the method used to attach cowling brackets for dzus/camloc fasteners to your hand layed up cowling, if your smart you will buy the cowling, and flox to this, but I did a hand lay up...lots of sanding left to do. * Floxing fuel VENT tubes into glass fuel tanks. * Floxing fuel flanges into fuel tanks... don't flox the screen fitting, buy the flanges from ACS (Aircraft Spruce) and this way you can remove the screen to clean it later. (Drill holes around the edge of the flange... I tell you it works! * Seal the fuel tank top/bottom with sticky flox to prevent leaks when you close it up--- per plans. (This doesn't work too well, you will still have a leak, which you patch with... FLOX!). Hmmm... if the fuel I use disolves epoxy, I should expect cotton clogging the fuel filters. Some auto gases may do this. * FLOX tools to your tool bench. * FLOX little bumps on the garage floor. Be careful to do this in the right place, as they are virtually immovable after this. (If you do it right, you will have a bump telling you when you have pulled your car in far enough. Too bad you have to finish the KR to use them.) FLOX Storage Both FLOX and Micro Slurry come in annoying double bags that are twistie tied. Opening FLOX without eye and nose protection will make you sneeze, Opening Micro Slurry without eye and nose protection will make you sneeze, and may cause you some annoying eye, nose and throat pain for a while later. Use a dust mask and goggles. I imeediately move my FLOX and Micro Slurry, into a dishwasher cleaned plastic container. Successful types are (for dry micro) 2&3 liter bottles (wide mouth). For FLOX, I have found that there is a plastic CAT food container that has a 3" flip lid. Both of these work MUCH better poring when you have your latex gloves on, and if you get FLOX/Micro all over them, so what... get another! -- Regards Ross ------------------------------ Date: Mon, 12 Jan 1998 15:40:48 -0800 From: Ross Youngblood Subject: Re: KR: Seat belts/harnesses Oscar Zuniga wrote: > > MikeT wrote: > >and even seatbelts with airplane-style buckles for less than $20. > > > > I have questions about this, too. I noticed some outstanding full > harnesses in the Summit Racing catalog, for prices way less than in the > aero catalogs. Why the big disparity in price? If it's good enough for > a racing car... > > Oscar Zuniga > Medford, Oregon I looked at this too, I found that Whitney had real cheap belts, and I wondered about the quality. Airplane belts have to be tested someplace at somepoint to become "TSOed", this is where the $$$ comes from. However the basic technology is the same, so I suppose that some good racing safety belts would be good. However, JC Whitney belts might be a crap shoot regarding quality. I think the two areas to look for would be the strength of the fittings, and the quality of the sewing around the fittings. I think that the basic nylon would be the same strength, but this could vary as well. I knuckled under and shelled out $80/ea for two sets of harnesses from Wicks or ACS (don't recall), however I was looking real hard at some HOT PINK sholder belts in the back of HOT VW, they quit advertising them when I was ready to buy. They were $65, not a great savings. In general the racing seatbelts I found were only slightly cheaper than the aircraft stuff. -- Ross ------------------------------ Date: Mon, 12 Jan 1998 15:45:04 -0800 From: Ross Youngblood Subject: Re: KR: Compass Oscar Zuniga wrote: > > MikeT wrote: > >Browsing the latest JC Whitney catalog, I found a number of things that > look > >interesting, such as lots of low-priced instruments > > Sorry I forgot to mention this in my other post; there is a nice looking > in-dash 'wet' compass in the Whitney catalog as well, and even with > lighted dial. Of course costs way less than a standard Airpath. Wonder > if it would be good enough for use in a homebuilt? Why not? Maybe > doesn't include means of adjusting/swinging? > > Oscar Zuniga > Medford, Oregon I saw this one too. It would meet the requirements for certification. I went with an Airpath. I've got two other compasses if anyone wants them. A pedastal mount Airpath (retails for about $70), and a WWII vintage panel mount (bigger..heavier). Some of you with gull wing canopies might be able to use the overhaed pedastal mount. It might need a rebuild kit, or it might just need some fluid. The rebuild kits are available from ACS. I would let this thing go for about $25.00. The WWII compass, well, make me an offer. -- Ross ------------------------------ Date: Mon, 12 Jan 1998 15:50:18 -0800 From: Ross Youngblood Subject: Re: KR: Re: fiberglass skins?? KMcken7414 wrote: > > I am new to the KR's and still learning. My question is this. After covering > the sides of the fuselage with ply, do you then go over it with glass and > resin or is there foam included in this? > > Thanks for the input. > Keith Keith, This is definatly a FAQ (Frequently asked question). I thought I would have to do somthing when I started to hide the wood grain. Didn't want anyone to see that it was a Wood airplane. Then I saw a couple of completed projects, and decided that regular paint finishing would be adequate. There are some folks who have placed a single layer of fine glass cloth over the plywood. I think it is extra work, but it is endorsed as a covering technique (Tony Bengilis Sportplane Construction Series and here on KRNET). -- Ross ------------------------------ Date: Mon, 12 Jan 1998 15:47:35 -0800 From: Ross Youngblood Subject: Re: KR: Compass I think you can CALIBRATE most altimeters. I got a cheap altimeter from Chief, and it came with some calibration stats. I plan to run my system through a Pitot/Static test as I get done anyway as I have a transponder/encoder in my KR, and don't want to report an altitude different from what the little box is saying. - -- Ross Kr2dream wrote: > > Be careful - it might be a Chinese unit. The Chinese altimiters look just > like the United units but looks are deceiving. They have been tested to be > many hundred feet off. As one chinese importer told me "It doesn't make any > difference, you can see how high you are anyhow!" > > Cheap doesn't always mean just a lower price. > > Bob Lasecki > Chicago ------------------------------ Date: Mon, 12 Jan 1998 19:15:31 -0500 From: Donald Reid Subject: Re: KR: Spar width errors in plans. Ross Youngblood wrote: > I had an EAA tech counselor puzzled about the outer spars only > having webbing on one side... so it might be a good idea to put the > webbing on both sides anyway. > > -- Ross In the original, very light KR-1 and -2, there was no need to have the extra shear web. As the plane has gotten bigger and heavier, it needs the increase in strength. - -- Don Reid Bumpass, Va. mailto:donreid@erols.com http://www.erols.com/donreid/kr_page.htm ------------------------------ Date: Mon, 12 Jan 1998 16:16:01 -0800 From: Ross Youngblood Subject: Re: KR: News-letters Jerry, I will remove you. If you would like I can add you KRNET-DIGEST, this sends an email once every couple of days which contain all the posts to KRNET in that time. I will remove you from the list. -- Regards Ross Jerry and Sandy Weiland wrote: > > Dear Ross, > > As much as I enjoy reading all the mail that goes between KR people, I'm > sorry but must ask to be removed from the mailing list. I'm getting 15 -30 > emails a day and it's just too much. When I originally got on the list, > there was an address and message to remove myself but unfortunately, I lost > it. If you can take me off, please do, if not please send instructions and > I'll do it. > > Yours, Jerry Weiland > > ---------- > > From: Ross Youngblood > > To: KRNET > > Subject: Re: KR: News-letters > > Date: Monday, January 12, 1998 6:21 PM > > > > Michelle, > > > > You are in luck. The newsletter had fallen down for a bit, but > > Monte Miller (Past KR builder) picked up the editorship and is > > breathing new life into the mail newsletter. > > > > > > > > KR Newsletter > > 624 University DR > > Suite 199 > > Denton, TX > > 76201 > > > > Rates: > > $20.00/yr USA > > $25.00/yr Canada > > $30.00/yr Overseas > > > > This informaiton is also available online at: > > > > http://www.krnet.org/KRnewsletter.htm > > > > (or go to) http://www.krnet.org, and click on SnailMail Newsletter. > > > > -- Ross > > > > Michele Bucceri wrote: > > > > > > My apolgies in advance if my question is trivial. > > > > > > I've read many times on KRNet about some news-letters. > > > How can I get them? Is it automatic when you buy the plans, or should I > > > register somewhere? > > > > > > By the way, there is somebody out-there that have some unused set of > KR2 > > > / KR2S plans to sell? > > > > > > Cheers, > > > Michele > > > -- > > > MBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMB > > > Michele Bucceri > > > E-mail: mailto:michele.bucceri@italtel.it > > > MBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMB ------------------------------ Date: Mon, 12 Jan 1998 16:27:49 -0800 From: Micheal Mims Subject: Re: KR: Re: fiberglass skins?? At 03:53 PM 1/12/98 EST, you wrote: >I am new to the KR's and still learning. My question is this. After covering >the sides of the fuselage with ply, do you then go over it with glass and >resin or is there foam included in this? > Glassing over the plywood is an option but its not required. It may help protect the plywood from the weather if you are planning to park out side. No foam is used. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Oh My,.......Its 1998!! mailto:mikemims@pacbell.net http://home.pacbell.net/mikemims ------------------------------ Date: Mon, 12 Jan 1998 18:13:40 -0700 From: Ron Lee Subject: Re: KR: Break System Question At 02:30 PM 1/12/98 -0800, you wrote: >I am presently building a KR2S and am having trouble with the brake master >cylinder installation. My rudder pedals were fabricated from tubing and are >hung from above and I have no ideas on the linkage to the brake cylinders. I >would like to have toe brakes but do not want to put pressure on the rudder >when I apply the brakes. I am interested on how others have solved this >problem. > >Dan Shervheim >Dan@aol.com Perhaps you should rethink your comment. I suspect that you would want FULL RUDDER travel BEFORE you ever apply brakes in most cases. Any comments from the KR peanut gallery? Ron Lee ------------------------------ Date: Mon, 12 Jan 1998 20:10:55 EST From: KMcken7414 Subject: Re: KR: Re: fiberglass skins?? Thanks Ross. I was wondering if I could just lay some glass on top of the ply. I guess so. ------------------------------ Date: Mon, 12 Jan 1998 20:17:05 EST From: EagleGator Subject: KR: Test Plan Deficiency (was "an ungrateful comment...") In a message dated 98-01-12 18:05:02 EST, Ross wrote: << TAXI test the airplane for a while. Try to rattle all the nuts and bolts loose. Then get a flashlight and go over the plane looking to be sure you didn't. (General inspection) Do this again. (Several times?) Then do a high speed taxi test.... including some full power runups. Get out the flashlight. >> This is an excellent point, and upon review of the taxi test section, I found that I left out another extremely important part of this inspection. You need to take a look for any gaps or cracks that may have developed in your fuselage or firewall structure that could allow carbon monoxide to enter the cockpit. This is best done with two people, one with his head down inside the airplane and the other with a high intensity light directed at the outside of the airplane. If the person inside the aiplane sees any light, there is work to be done. I guess this means version 9 is in the works... Keep the comments and suggestions coming! Cheers! Rick Junkin EagleGator@aol.com St. Louis MO EAA#374066 ------------------------------ Date: Mon, 12 Jan 1998 20:12:31 EST From: KMcken7414 Subject: Re: KR: Re: fiberglass skins?? Thanks for the input Mike. I have never seen one group of guys who are so supportive and willing to help like the ones on the KRNet. Thanks again. Keith ------------------------------ Date: Mon, 12 Jan 1998 20:28:34 EST From: BSHADR Subject: KR: Old Newsletters In a message dated 98-01-12 17:56:38 EST, Mike wrote: << Gee I wonder if the issues I have (1 - 70) can be copied and redistributed?? If they are considered "unavailable" :o) >> Mike: Ernie Koppe, who published issues 1 through 100 +/-, gave us permission to copy and distribute his issues freely with no restrictions. He said he never sold the rights of those issues to anybody and as such he was the rightful owner (his words). I do think I know were there is a realtively complete set that could be set up for copying at a copy shop and anyone who wanted a full set could just order them direct. If anyone is interested, please Email me direct. Use "KR Newsletters 1 -100" as the subject line so I can separate your Email from the other 100+ I get every day. Please don't turn this post into a debate on who has the rights to copy what. That horse has been sent to the glue/pet food factory a year ago and can't be located except for the pet food label I have left from the cat's dinner fix'ins last night. (No Oscar - her dinner, NOT MINE!) Randy Stein BSHADR@aol.com ------------------------------ Date: Mon, 12 Jan 1998 19:32:56 -0800 From: MARVIN MCCOY Subject: Re: KR: News-letters Micheal Mims wrote: > > > Gee I wonder if the issues I have (1 - 70) can be copied and redistributed?? > If they are considered "unavailable" :o) >----------------- Michael: If they can, I would be very interested in them. When I purchased all of the back issues (this was before Monte took over the newsletter) I thought I was getting a complete set. No such luck. Marvin McCoy Seattle, WA. North end of Boeing field mr.marvin@worldnet.att.net - --------------- ------------------------------ Date: Mon, 12 Jan 1998 22:21:39 EST From: JEHayward Subject: Re: KR: Why does T-88 start looking weird? In a message dated 98-01-12 17:17:46 EST, you write: << Something else for you t-88 mixers, sometimes the resin will look as though it has crystallized. If this happens you can set the bottle of resin in a pan of water that is around 130 degrees and it will clear back up. >> Mine must be beyond that. I didn't check the temp but did try hot tap water which seemed to help a little. The major think I noticed was that the resin got a lot thicker and my batch time was down to about 15 min or so. Needless to say I tried this on scrap and not the plane. Anyway, I think the shelf life of the 2 half gallon containers did me in. I only lost about 25% of it anyway which is about what I'd have come out expense wise buying the quart sizes which probably would have done better as far as stock turn-over goes. Jim Hayward ------------------------------ Date: Mon, 12 Jan 1998 22:03:48 From: Austin Clark Subject: Re: KR: Spar width errors in plans. > I had an EAA tech counselor puzzled about the outer spars only >having webbing on one side... so it might be a good idea to put the >webbing on both sides anyway. > > -- Ross > > I built my outer spars like it shows in the manual and I proudly proclaimed to my wife that I had finished the spars. Later, I saw the note on the KR2S spar details drawing and I scarfed the additional webbing onto the short pieces that were already on the spar. I thought it was going to be a bugger, but it turned out ok. She had gone shopping so I did'nt have to 'eat crow'! Austin Clark Pascagoula, MS http://www.datasync.com/~itac/ ------------------------------ Date: Mon, 12 Jan 1998 20:15:29 -0800 From: "John Bouyea" Subject: KR: Re: Why does T-88 start looking weird? Dick at System 3 said there is some variation between batches in regard to color. Typically, it is nothing they worry about. Somebody mentioned test batches/ blocks to verify the epoxy is NOT the weak link. This is the preferred method at System 3. Mike pointed out crystallization is a different matter and MUST be remedied by warming the product until the crystals dissolve. I believe steady, low warming is preferred. As to getting sufficient product in place before clamping, perhaps I'm paranoid about the process. I've been single coating the plywood lightly between the pencil lines I've traced and skuff sanded. I next place a heavier coat on the frame I'm bonding and stick the two together. To keep the faith towards a light project, this requires scraping the squeeze-out. Bobby Muse once pointed out that the recovered epoxy can be used to seal the inner skin by smearing with a mixer stick as long as it hasn't "gone off." Have we missed anything? John Bouyea johnbouyea@worldnet.att.net kr2s - fitting the top cross members Hillsboro, Oregon - ---------- > > > From: Martin Mulvey > > > To: krnet-l@teleport.com > > > Subject: KR: Re: Why does T-88 start smelling weird? > > > Date: Sunday, January 11, 1998 12:45 AM > > I've noticed that the hardner in my T-88 has become thicker and darker > in color. It's like cold honey and about the same color. The strength > seems fine and it mixes fine with the resin. By the way, the glue mixer > gun which has 8oz tubes is a great way to insure 50/50 mixing of even > the smallest batches. I found it especially useful when it came time to > skin the fuse sides and then the fuse bottom, since you have to lay a > bead which is about 100' long including all the cross pieces. It lays a > bead about 1/16" diameter which is optimum for 5/8" glue cover under > pressure. > -Tom ------------------------------ Date: Mon, 12 Jan 1998 20:19:00 -0800 From: "John Bouyea" Subject: KR: Weight Check/ Boat's complete! The boat is done! Well, at least everything in chapter one is finished. It's at 42 pounds. How I'm doing guys? What weights did anyone else record? On to the spars! John Bouyea johnbouyea@worldnet.att.net kr2s - laying out the spars for lamination Hillsboro, Oregon ------------------------------ Date: Mon, 12 Jan 1998 23:35:37 EST From: MikeT nyc Subject: Re: Re(2): KR: Accident Stats >Pull the power off for landing and then >the dukey really hits the fan! Pucker factor increases to the 10th power as >you roll in nose down trim and notice the control yoke is against the >forward stop! Been there done that and I DON'T EVER WANT TO DO IT AGAIN!! > > >Now imagine that you just departed your favorite runway and during climb-out >all seems dandy, then as the engine sound goes away you find yourself >decelerating rapidly,.. of course you lower your nose to keep flying speed >but the stick is against the forward stop and the nose is still rising! Life >all of a sudden really sucks!! > >You can fly over gross but by all means don't fly with an aft CG! It was >the one and only time an airplane really scared me, can you tell? :o) How did you manage to be here to tell us about it? Mike Taglieri ------------------------------ Date: Mon, 12 Jan 1998 20:55:16 -0800 From: Micheal Mims Subject: Re: KR: Weight Check/ Boat's complete! At 08:19 PM 1/12/98 -0800, you wrote: >The boat is done! Well, at least everything in chapter one is finished. > >It's at 42 pounds. How I'm doing guys? What weights did anyone else >record? > I think my skinned boat was just under 50 pounds. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Oh My,.......Its 1998!! mailto:mikemims@pacbell.net http://home.pacbell.net/mikemims ------------------------------ Date: Mon, 12 Jan 1998 21:35:16 -0800 From: Micheal Mims Subject: Re: Re(2): KR: Accident Stats At 11:35 PM 1/12/98 EST, you wrote: >How did you manage to be here to tell us about it? > >Mike Taglieri > Well luckily I was flying a STOL twin, a Britain Norman Islander. I retracted the flaps which helped and at the same time went to full power to get the airspeed back up. I came around the second time a little hot and with only take-off flaps. It seems the ramp agent was in a hurry to get home and stuck 1200 pounds of pepsi in an area just under and aft of the wing and another 600 pounds in the aft baggage compartment. There should have been at least 400 pounds behind the pilots seat to even get into the aft limit! If I would have been in any of the other under powered aircraft we used I would be dead for sure! I landed OK on the second try but after returning to base I hunted down our ramper and we had a little tiff! He was trained in the loading procedures of the BN-2 and knew the importance of W&B and CG. ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ Micheal Mims Oh My,.......Its 1998!! mailto:mikemims@pacbell.net http://home.pacbell.net/mikemims ------------------------------ Date: Tue, 13 Jan 1998 01:02:36 EST From: MikeT nyc Subject: Re: KR: Seat belts/harnesses >MikeT wrote: >>and even seatbelts with airplane-style buckles for less than $20. >> > >I have questions about this, too. I noticed some outstanding full >harnesses in the Summit Racing catalog, for prices way less than in the >aero catalogs. Why the big disparity in price? If it's good enough for >a racing car... I bet it's just economies of scale. Whitney's probably sells more of these seatbelts per year than the total number of general aviation planes in the United States. By contrast, for the tiny number of airplanes that need new seatbelts every year, the aero catalogs have to stock many different kinds, and do FAA paperwork besides. Mike Taglieri ------------------------------ Date: Tue, 13 Jan 1998 01:02:42 EST From: MikeT nyc Subject: Re: KR: Old Newsletters >Ernie Koppe, who published issues 1 through 100 +/-, gave us permission to >copy and distribute his issues freely with no restrictions. He said he never >sold the rights of those issues to anybody and as such he was the rightful >owner (his words). I do think I know were there is a realtively complete set >that could be set up for copying at a copy shop and anyone who wanted a full >set could just order them direct. If anyone is interested, please Email me >direct. Use "KR Newsletters 1 -100" as the subject line so I can separate >your Email from the other 100+ I get every day. > >Please don't turn this post into a debate on who has the rights to copy what. >That horse has been sent to the glue/pet food factory a year ago and can't be >located except for the pet food label I have left from the cat's dinner >fix'ins last night. (No Oscar - her dinner, NOT MINE!) This is wonderful news. The Koppe Newsletters date from the period when Ken Rand and the early builders were still finishing the design of the plane, and they have a tremendous number of innovative ideas (as well as many bad ideas people keep repeating because they don't know they're bad). If Ernie has given us the rights to reproduce them, how about getting together a clean set then copying and glue binding them into a book (e.g., like Tony Bingelis's books). These could be sold, both here and in Monte Miller's newsletter, and the profits split with Ernie. Mike Taglieri ------------------------------ Date: Tue, 13 Jan 1998 01:02:39 EST From: MikeT nyc Subject: Re: KR: NLF Thoughts In a message dated 98-01-12 18:03:12 EST, you write: >>There is no such thing as a free lunch, each airfoil is a collection of >>problems and solutions. Each one is designed for one specific mission >>in life and will not work well in all situations. > >That's exactly right. And this airfoil in particular wasn't designed for >the light wing loading and lower Reynolds numbers characteristic of the KR >series. That's why I'm waiting for the one that was specifically designed >for US. Also, we've been asked to come up with a list of specific design >goals to shoot for. I'd think that since we already have the proven RAF48 >to cover the pilots who like to land slow and stall gently (don't we all!), >the mission for the new one might be more biased toward lower drag and >higher top end speed. Given the tools that'll be used to design this new >airfoil, I think they'll be able to fine tune away the high pitching >moments at whatever speed we'd like to cruise at. My wings are definitely >"on hold" until then. I hope this new wing will also be as tolerant of less-than-perfect construction as the RAF48 is. Even if someone in this project starts making wingskins, I assume some people will want to build them with hotwiring or even sanded urethane. Mike Taglieri ------------------------------ Date: Tue, 13 Jan 1998 01:02:32 EST From: MikeT nyc Subject: Re: Re(2): KR: Accident Stats In a message dated 98-01-12 02:22:57 EST, you write: >>The published KR stall speed is actually better than that of a clean 172, >and >>just 3 mph higher than a 172 with full flaps -- the KR also has a better >glide >>ratio when the engine dies. Tthe problem may be that people in all planes >>tend to panic when they lose an engine, maybe because they never get >practice >>at it after they get their ticket. > > > > >Is that so?....I was under the impression that the "clean" stall speed (KR2) >was somewhere around 50-55 MPH or so (I read that somewhere...I'll try to >locate the article) You're right -- the published stall speed of a KR-2 is 52 mph. But the published stall speed of a "clean" 172 is 57 mph, and 49 mph for full flaps. Of course, people can build a KR anyway they want, so I guess a very overweight KR could have a much higher stall speed. Mike Taglieri ------------------------------ Date: Tue, 13 Jan 1998 10:26:52 +0100 From: Michele Bucceri Subject: Re: KR: NLF Thoughts Donald Reid wrote: > > I had to work this weekend, but it was slow and I had a chance to do > some number crunching on the NLF(1)-0115 airfoil and I want to pass on > what I found. Some of it may be old news and some of it may have a bit > of sense in it. > > I took three airfoils and ran them through an airfoil analysis program > to calculate the lift, drag, and pitch moment data. I used the RAF48, > the NLF(1)-01115, and the NACA 747A315, the one I am using. I did this > so I would have a consistant basis for comparison. The results for the > 747A315 agreed pretty well with the published data so I believe that the > comparison will be valid. > > The RAF has the highest lift coefficient and a gentle stall, but high > drag. > > The 747A315 has the lowest drag coefficient, but also the lowest lift > coefficient, so you have to increase wing area for a good landing > speed. It also has the most gentle stall of the three and the lowest > pitch coefficient. > > The NLF has a very good lift coefficient, a reasonable low drag > coefficient, but a very high pitch coefficient and an sharper stall. > > Then I scaled the wing area, aspect ratio, and taper ratio so that the > plan form and the unflapped stall speeds were the same. Then I scaled > the horizontal stabilizer so that the volume coefficient were the same. > I did this by changing the stab. size, but not the length of the > fuselage. The idea was to model the same fuselage, with the different > wing and tail. > > I looked at design cases of 180mph and 90mph, with full forward and full > aft CG. In all three cases, the neutral stability point was between 34 > and 35 percent of the mean aerodynamic chord. > > What I found was that the wing drag for the 747 was about 5% lower than > the RAF, the 747 required the largest area of the three, since it has > the lowest lift coefficient. The NLF was about 20% lower than the RAF, > since the lift coefficient was almost the same, but the drag was so much > lower. When you add in the drag caused by the tail, the NLF looses some > of its advantage, but only about 5% (net about 15% over the RAF). This > is because the NLF has a much high pitch moment. That means that as the > speed increases, the airfoil wants to pitch nose down. In fact, the > downward tail force at 180mph was about 2.5 times higher on the NLF than > on either of the other two. Up to this point, there were no surprises. > > I did note two things that may be of interest. The NLF runs out of > laminar flow at a relatively low lift coefficient, on the order of > 0.65. Since your Vx speed is generally at a lift coefficient of about > 1.0, the NLF will have a significantly higher drag during climb. This > translates into a decreased rate of climb. The other thing that is > interesting, at least to me, is that if you size the horizontal > stabilizer for a realistic volume cofficient, at forward CG and high > speed, the tail will/can be well outside of its laminar flow region. In > other words, the elevator may need to work so hard that the drag will > increase dramatically. In certain cases, increasing the tail size would > significantly decrease the drag since the lift coefficient would be in > the laminar region at all times. > > Any question? I will try to answer. > > -- > Don Reid > Bumpass, Va. > mailto:donreid@erols.com > http://www.erols.com/donreid/kr_page.htm Great work Don. Just a question about the program you've used. You speaks about "...airfoil analysis...", "...NLF runs out of laminar flow..." and " ...gentle stall...", so I guess that you ran a two dimensional CFD program with boundary layer and post-stall computation. Is that true? If yes, tell me where and how I can get this program! I'm looking for it. What's your experience with the moment evaluation with CFD programs? Mine is that they never get the true value. They are very good for evaluating the lift curve, good for the drag, and poor for the moment. My be I've ever used bad programs. Another question. What about airfoil contamination vs laminary flow for the 747? I've seen the diagrams of this airfoil on Abbot, and it seems very good, but everytime I see a laminar airfoil with good performance in the laminar region, and poor performance outside, I get scared. May be that my scare is because of poor experience. Thank a lot! Michele (the Italian KR2S plan-finder) - -- MBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMB Michele Bucceri E-mail: mailto:michele.bucceri@italtel.it MBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMBMB ------------------------------ End of krnet-l-digest V2 #11 ****************************