Original Posted By: "H. Marvin Haught"
Builders,I am a member of a design team that spends a chunk of time every year working onan important design exercise in light planes. It doesn't look anything likea Pietenpol, but it may very well yield some spin off components and ideas thatwill be useful to Piet guys on a budget. If people are interested, I was goingto bring some of this stuff to Brodhead and Oshkosh as show and tell.The design parameters the four of us work on are misleadingly simple, but we investa lot of time to try to come up not with a basic configuration to meet themon paper (anyone can do that), but we are working on every little element,down to the carb and throttle linkage, every nut and bolt and hour of constructiontime accounted for. The mission looks like this:1) 100% LSA legal.2) $10,000 total budget, including plane, engine, tools, instrumentation3) 1,000 hour build time, (does not include reading or learning, just work)4) Plane is safe for any competent C-150 pilot to solo, with no further training.5) Plane lives outside, tied down, without significant degrading of airframe.6) Plane can climb at 750 fpm on a standard day with 250 pound pilot and 4 hoursof fuel.7) Plane can fly 100 hours in a year for an operations budget of $2,500, includingfuel oil, tie down.----------------------------------This is a lot harder to do than it looks at a glance. We are not speaking of whatone world class scrounger/master builder can do, we are speaking of regularguys working on their first plane, buying the stuff from available sources. ManyPiets could make #1,2, 6, and 7, but they could not get 4 and 5, and probablynot 3 either.The plane's layout as it exists today is a fluid concept, because a number of configurationscan meet the requirement, but to get into the budget, the detailsall have to be worked out. Here is an example of testing to find a $159 carb,new, off the shelf:
http://flycorvair.net/2012/05/05/in-sea ... uretor/The design plane now is an ugly single-seat tri-gear, Corvair powered plane madeout of sheet metal. I would much rather have a Pietenpol. I am not sure we willever build the design plane, and we don't actually have to for the exerciseto pay real benefits in testing and spin off ideas.Here is one that may interest some Pietenpol guys: Wheels and tires. You can'tmeet a $10K budget if you are going to donate 12% of it to Cleveland and McCrearyjust for wheels and tires. One of the things our design uses are 4.80 x 8"trailer wheels and tires. Think I am kidding? Wonder if it would work? Look atthese 2002 photos of our test mule, a Skycoupe, that flew on these for years.The last photo shows the tires pretty well. The plane had highly effective mechanicalband brakes:
http://flycorvair.net/2012/02/27/2700cc ... hotos/Hubs for trailers are ridiculously heavy cast steel, but it is very easy and cheapto make lightweight replacements from steel tubing and a disk hogged out ina minute by a Hi-Def. Plasma cutter. Wheels, tires, hubs, bearings and brakes,now looking like $200. This size trailer tire is the same height as a 6x6,has less drag, might be unbreakable on a plane, and is only 2 pounds heavier.It is also available for thirty nine bucks, 24/7 from an aircraft supply storewith 4,000 local outlets called Wal-mart. Looking for a slightly bigger one? The 4.80 x 12" is 21" tall and weighs only 17lbs per wheel and tire, which are worth $49 brand new. At a guess, it probablyhas less drag than a spoke wheel 26" tall, it certainly does with a disc cover.They are plenty strong even in side loads. (think fishtailing 2,000 poundutility trailer at 55 mph) Again, not for everyone, but a number of these ideasin a single basic plane can make a difference. The most simple flying Piet, even if it is not aesthetically pure, or record light,provides more satisfaction than any masterpiece that is over budget and yearsbehind schedule, sitting in a garage, that will fly "someday." We flew theSkycoupe and its trailer tires to many airshows. in the second incarnation weeven had a turbo on it. Practical people loved it. The 1 of 500 who made a negativecritical remark was treated to me getting "100% NJ" on him, and loudlyasking in front of everyone for him to show us all his own plane, which invariablydidn't exist, and then share with him T.R.'s quote on critics.There are many places to apply ideas like this to a Piet build. I read last yearsnotes on how to make 3 pane windshields and frames. You guys who made themand shared the ideas deserve kudos, they look great. Would you like another ideathat takes less time? Anyone with a cad program or a sheet of cardboard canknock out a flat plate pattern. This can be traced onto a 1/8" sheet of castsheet of lexan, and fed straight into a sheet metal brake. If you want a coollooking frame, tape it off and paint it directly on the sheet. If you want the'riveted' look, drill 1/8 holes and glue in short rivets and paint over them.I didn't bother to do either of these on my Piet, I just made the lexan partsin 30 minutes, and spent about two hours making little bottom frames. I meantto dress them up, but once flying I left them plain for a year. There is a photohere:
http://flycorvair.net/2013/12/19/pieten ... -cabanes/I am not the right guy to ask if the question is "How pretty can it be made?" butI am often a good person to ask if the question is "Is there a faster/lessexpensive/ airworthy way of doing this?" -ww.--------------------------------------------------------It is not the critic who counts; not the man who points out how the strong manstumbles, or where the doer of deeds could have done them better. The credit belongsto the man who is actually in the arena, whose face is marred by dust andsweat and blood; who strives valiantly; who errs, who comes short again andagain, because there is no effort without error and shortcoming; but who doesactually strive to do the deeds; who knows great enthusiasms, the great devotions;who spends himself in a worthy cause; who at the best knows in the end thetriumph of high achievement, and who at the worst, if he fails, at least failswhile daring greatly, so that his place shall never be with those cold andtimid souls who neither know victory nor defeat. T.R. Paris France, 1910.Read this topic online here:
http://forums.matronics.com/viewtopic.p ... __________