---------------------------------------------------------- Pietenpol-List Digest Archive --- Total Messages Posted Fri 03/21/14: 23 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 05:17 AM - Re: Vasek's Pietenpol project (Vasek) 2. 05:34 AM - Re: Re: Vasek's Pietenpol project (Gary Boothe) 3. 06:29 AM - books (Douwe Blumberg) 4. 08:21 AM - Re: books (aerocarjake) 5. 08:31 AM - Re: Vasek's Pietenpol project (jarheadpilot82) 6. 08:43 AM - Re: Re: Vasek's Pietenpol project (Michael Perez) 7. 08:46 AM - Re: Re: Vasek's Pietenpol project (Jack Phillips) 8. 08:54 AM - Re: Re: Vasek's Pietenpol project (larharris2 Harris) 9. 10:09 AM - Re: Re: Vasek's Pietenpol project (Michael Perez) 10. 12:13 PM - verbosity (Lawrence Williams) 11. 02:47 PM - Re: CG vs Wheels Location (larharris2 Harris) 12. 03:02 PM - Re: verbosity (William Wynne) 13. 03:22 PM - Re: CG vs Wheels Location (jarheadpilot82) 14. 04:55 PM - Re: verbosity (jim hyde) 15. 05:30 PM - Re: CG vs Wheels Location (William Wynne) 16. 05:57 PM - Re: verbosity (William Wynne) 17. 06:00 PM - Re: Re: CG vs Wheels Location (airlion2@gmail.com) 18. 06:05 PM - Re: Re: CG vs Wheels Location (airlion2@gmail.com) 19. 06:06 PM - Re: CG vs Wheels Location (Chris) 20. 06:06 PM - Re: Re: CG vs Wheels Location (larharris2 Harris) 21. 07:50 PM - Re: CG vs Wheels Location (Don Emch) 22. 09:55 PM - Re: CG vs Wheels Location (William Wynne) 23. 10:05 PM - Re: CG vs Wheels Location (Gary Boothe) ________________________________ Message 1 _____________________________________ Time: 05:17:57 AM PST US Subject: Pietenpol-List: Re: Vasek's Pietenpol project From: "Vasek" Recently I had a guy here who wanted to take a look, and when he came I told him "this is going to be a replica of S.E.5a" ..and he believed ..it really looks like S.E.5a :) I am now wondering about length of the landing gear - the V on the side - how long it should be. Currently it has about 70cm, but I found out that this length is designed for Piper wheels. I am going to use wire wheels. So I am worried that I will have to make the V on both sides again, shorter. What do you think? Can anyone with wire wheels (on airplane please :D ) measure the length of the front tube (on the V, which connects the wheel with sides of fuselage). Thank you! -------- My production of WW1 propellers, trophies and constructions: Read this topic online here: http://forums.matronics.com/viewtopic.php?p=420712#420712 ________________________________ Message 2 _____________________________________ Time: 05:34:03 AM PST US From: "Gary Boothe" Subject: RE: Pietenpol-List: Re: Vasek's Pietenpol project Vasek, You can do this yourself! Estimate the height of the tail with the tailwheel arrangement that you will have. Prop up the tail to that point. Next, raise the front on sawhorses and blocks until you attain a suitable 'deck angle' ( the angle of the upper longerons, measured over level ground). I started with 13=81=B0, but fle that was too much. I=99m now at 11=81=B0 and much more comfortable. Once the deck angle is set, you can see if the wheels you have will work, or know which size wheels to look foror rework your gear. Gary Boothe NX308MB -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of Vasek Sent: Friday, March 21, 2014 5:17 AM Subject: Pietenpol-List: Re: Vasek's Pietenpol project bigon2@seznam.cz> Recently I had a guy here who wanted to take a look, and when he came I told him "this is going to be a replica of S.E.5a" ..and he believed ..it really looks like S.E.5a :) I am now wondering about length of the landing gear - the V on the side - how long it should be. Currently it has about 70cm, but I found out that this length is designed for Piper wheels. I am going to use wire wheels. So I am worried that I will have to make the V on both sides again, shorter. What do you think? Can anyone with wire wheels (on airplane please :D ) measure the length of the front tube (on the V, which connects the wheel with sides of fuselage). Thank you! -------- My production of WW1 propellers, trophies and constructions: =C3=A2=CB=86=C2=BC Read this topic online here: http://forums.matronics.com/viewtopic.php?p=420712#420712 http://www.matronics.com/Navigator?Pietenpol-List http://www.matronics.com/contribution ________________________________ Message 3 _____________________________________ Time: 06:29:45 AM PST US From: "Douwe Blumberg" Subject: Pietenpol-List: books Ck out "Flight of Passage". Great "coming of age" adventure book about two kids flying a cub across America in the sixties. Very fun. Douwe ________________________________ Message 4 _____________________________________ Time: 08:21:52 AM PST US Subject: Pietenpol-List: Re: books From: "aerocarjake" Don't forget the water bag..... -------- Jake Schultz - curator, Newport Way Air Museum (OK, it's just my home) Read this topic online here: http://forums.matronics.com/viewtopic.php?p=420730#420730 ________________________________ Message 5 _____________________________________ Time: 08:31:23 AM PST US Subject: Pietenpol-List: Re: Vasek's Pietenpol project From: "jarheadpilot82" Vasek, Your steel tube fuselage looks great! I have attached a link to a previous posting I made showing my steel tube fuselage with the door option for the front seat- http://forums.matronics.com/viewtopic.php?t=100890&highlight I would love to say that I designed it, but I did not. However, the highly capable William Wynne did. You might want to look at the tubes he added to reinforce the fuselage and see if you might need similar reinforcement. -------- Semper Fi, Terry Hand Athens, GA Read this topic online here: http://forums.matronics.com/viewtopic.php?p=420732#420732 ________________________________ Message 6 _____________________________________ Time: 08:43:56 AM PST US From: Michael Perez Subject: Re: Pietenpol-List: Re: Vasek's Pietenpol project I setup my gear more or less as Gary describes. Position the plane with it sitting on its tail wheel, raise the nose until you achieve your desired deck angle, fit/locate main landing gear. If God is your co-pilot...switch seats. Michael Perez Pietenpol HINT Videos KaretakerAero www.karetakeraero.com ________________________________ Message 7 _____________________________________ Time: 08:46:51 AM PST US From: "Jack Phillips" Subject: RE: Pietenpol-List: Re: Vasek's Pietenpol project For what it=99s worth, my Pietenpol has a 13=C2=B0 deck angle and I wish I had a bit less =93 maybe 12=C2=B0. The problem with 13=C2=B0 is, the wing is nearly fully stalled in the 3-point position, which means you=99ve got to be very accurate in timing your flare on landing. The Pietenpol at such an AOA has so much drag that the time between when you get it to the 3-point position (13=C2=B0) and when it stalls is very short (feels like a second or less. If you flare a bit high, it will stall and =9Cdrop in=9D. A shallower deck angle allows you to flare it slightly high and let it float down to the runway as it bleeds off speed. Jack Phillips NX899JP Smith Mountain Lake, Virginia _____ From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of Gary Boothe Sent: Friday, March 21, 2014 8:34 AM Subject: RE: Pietenpol-List: Re: Vasek's Pietenpol project Vasek, You can do this yourself! Estimate the height of the tail with the tailwheel arrangement that you will have. Prop up the tail to that point. Next, raise the front on sawhorses and blocks until you attain a suitable 'deck angle' ( the angle of the upper longerons, measured over level ground). I started with 13=81=B0, but fle that was too much. I=99m now at 11=81=B0 and much more comfortable. Once the deck angle is set, you can see if the wheels you have will work, or know which size wheels to look foror rework your gear. Gary Boothe NX308MB -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of Vasek Sent: Friday, March 21, 2014 5:17 AM Subject: Pietenpol-List: Re: Vasek's Pietenpol project bigon2@seznam.cz> Recently I had a guy here who wanted to take a look, and when he came I told him "this is going to be a replica of S.E.5a" ..and he believed ..it really looks like S.E.5a :) I am now wondering about length of the landing gear - the V on the side - how long it should be. Currently it has about 70cm, but I found out that this length is designed for Piper wheels. I am going to use wire wheels. So I am worried that I will have to make the V on both sides again, shorter. What do you think? Can anyone with wire wheels (on airplane please :D ) measure the length of the front tube (on the V, which connects the wheel with sides of fuselage). Thank you! -------- My production of WW1 propellers, trophies and constructions: =C3=A2=CB=86=C2=BC Read this topic online here: http://forums.matronics.com/viewtopic.php?p=420712#420712 http://www.matronics.com/Navigator?Pietenpol-List http://forums.matronics.com http://www.matronics.com/contribution ________________________________ Message 8 _____________________________________ Time: 08:54:36 AM PST US From: larharris2 Harris Subject: RE: Pietenpol-List: Re: Vasek's Pietenpol project Michael=2C I have your set of videos=2C but I am watching them on pace with my construction progress. I haven't gotten to the part about landing gear yet if you discuss some of the location questions. This thread has explored setting the height of the gear. But have you any insight into the fore/aft location of the axle relative to the airplane CG? I have asked this questi on here before & gotten some good opinions. Any new thoughts? Lorenzo I setup my gear more or less as Gary describes. Position the plane with it sitting on its tail wheel=2C raise the nose until you achieve your desired deck angle=2C fit/locate main landing gear. Michael Perez =0A =0A =0A ============0A ============0A ============0A ============0A =0A ________________________________ Message 9 _____________________________________ Time: 10:09:14 AM PST US From: Michael Perez Subject: Re: Pietenpol-List: Re: Vasek's Pietenpol project Lorenzo, I don't believe I have any NEW thoughts, but I'll tell you my logi c for building mine.- I believe most of your questions will be answered i n the DVD, however, as with the entire series, they detail how I am buildin g my plane and don't reflect the various ways it can be done.=0A=0AThere we re some extensive tests done and articles written to the news letter about landing gear locations and CG. Those came out after I had my gear built, bu t still, I am glad I made mine the way I did. If you don't have these artic les, it would be well worth the effort to acquire them.=0A=0APietenpols are known for being tail heavy. I have been building mine with that in mind an d try to keep it light and keep it "balanced" (nose heavy, if you will...) I have talked with Mike Cuy and he informed me that he moved his gear, (woo d with the wire wheels)- 3" aft from the plans. Mike's plane is extremely nice and has been flying for 15+ years, so I had no issues copying his ide as. Going from memory, that moves the axle about 20" from the firewall. He explained that this allowed the tail to leave the ground early, potentially reducing ground friction and allowing him to get a clear view of the runwa y out front sooner. I moved my gear back the same 3". With this new locatio n, I set my deck angle to about a 10 deg.,- maybe less. As Jack noted, I wanted a little higher landing speed to have some better control authority and a shallow approach angle so I can see the runway longer into the landin g.- =0A=0AMoving the gear back changes the CG, but having built my plane as I have, I don't feel I will have any CG issues at all. I still expect to have near vertical cabanes...=0A-=0A=0AIf God is your co-pilot...switch seats.=0AMichael Perez=0APietenpol HINT Videos=0AKaretakerAero=0Awww.kareta keraero.com=0A ________________________________ Message 10 ____________________________________ Time: 12:13:18 PM PST US From: Lawrence Williams Subject: Pietenpol-List: verbosity How about if we all remember that Air Campers were flying safely long, long before Bingelis, EAA, Matronics, FAA, Corvairs and epoxy. I'm not advocating casien glue and cardboard but let's not get carried away by thinking that without our superior intellect and latest technology our creations will be somehow deadly. I am having a hard time keeping fiery barbs quivered just now so I'll end here. Larry Williams The abominable slowman (and curmudgeon emeritus) ________________________________ Message 11 ____________________________________ Time: 02:47:19 PM PST US From: larharris2 Harris Subject: RE: Pietenpol-List: CG vs Wheels Location Thanks=2C Michael. I have heard from others about "this is what I did." I v ery much appreciate the all the input from everyone. I'm still waiting for the WW Wt&Bal articles to arrive which may shed some more light on my quest ioning. And perhaps the curmudgeons will heap abuse on me for even consider ing deviating from the plans. But I'm looking for some general design guida nce on how (where) to locate the gear for a taildragger. Design guidance is pretty standard for allowable CG range=2C given the Cent er-of-Lift of the wing (%MAC). I'm beginning to believe that locating the g ear may be a matter of trial and error=2C though. You can't have the wheels too far out ahead of the CG or you will have controllability problems on l anding. On the other hand=2C if you get the wheels too far back=2C close to the CG=2C you nose over at the first application of brakes. I understand t hat others have had just this problem. I think building to the plans will not work for me because I intend to incl ude a wheel brake system. I'd like to hear if there is some range of design limits that I might start with. Or maybe I'll just pick a point others hav e tried with success & not worry about it. Lorenzo From: speedbrake@sbcglobal.net Subject: Re: Pietenpol-List: Re: Vasek's Pietenpol project Lorenzo=2C I don't believe I have any NEW thoughts=2C but I'll tell you my logic for building mine. I believe most of your questions will be answered in the DVD=2C however=2C as with the entire series=2C they detail how I am building my plane and don't reflect the various ways it can be done. There were some extensive tests done and articles written to the news lette r about landing gear locations and CG. Those came out after I had my gear b uilt=2C but still=2C I am glad I made mine the way I did. If you don't have these articles=2C it would be well worth the effort to acquire them. Pietenpols are known for being tail heavy. I have been=0A building mine with that in mind and try to keep it light and keep it "bala nced" (nose heavy=2C if you will...) I have talked with Mike Cuy and he inf ormed me that he moved his gear=2C (wood with the wire wheels) 3" aft from the plans. Mike's plane is extremely nice and has been flying for 15+ year s=2C so I had no issues copying his ideas. Going from memory=2C that moves the axle about 20" from the firewall. He explained that this allowed the ta il to leave the ground early=2C potentially reducing ground friction and al lowing him to get a clear view of the runway out front sooner. I moved my g ear back the same 3". With this new location=2C I set my deck angle to abou t a 10 deg.=2C maybe less. As Jack noted=2C I wanted a little higher landi ng speed to have some better control authority and a shallow approach angle so I=0A can see the runway longer into the landing. Moving the gear back changes the CG=2C but having built my plane as I have =2C I don't feel I will have any CG issues at all. I still expect to have n ear vertical cabanes... If God is your co-pilot...switch seats. Michael Perez Pietenpol HINT Videos Karetaker Aero www.karetakeraero.com =0A =0A =0A ============0A ============0A ============0A ============0A =0A ________________________________ Message 12 ____________________________________ Time: 03:02:42 PM PST US Subject: Pietenpol-List: Re: verbosity From: "William Wynne" Larry, I am taking your comments as some type of joke, because I am not sure why else anyone who has earned an ATP would make the kind of comment you just did. "Flying Safely" isn't the kind of term that I would choose to use. Since you have an ATP, I assume that at work you use the term Risk Management, and understand that while Pietenpols flew 80 years ago at a then acceptable level of risk, that it is perfectly OK for todays builders to look for a lower level of risk in their own plane today. In 1930's ATP's of that era flew DC-3s with flammable 5606 hydraulic fluid and extinguishers filled with Carbon Tetrachloride. Should DC-3 owners today abandon Skydrol and Halon? New guys reading this list see ATP after your name and have an expectation of valid risk management advice. Speaking out against discussing small, but important improvements, is not a particularly funny joke to me. I worked long and hard on the W&B project as an important risk management tool for builders. Perhaps this should buy a little credibility. Please share what contribution to your fellow builders you are working towards with your comments, I like to understand.-ww Read this topic online here: http://forums.matronics.com/viewtopic.php?p=420787#420787 ________________________________ Message 13 ____________________________________ Time: 03:22:53 PM PST US Subject: Pietenpol-List: Re: CG vs Wheels Location From: "jarheadpilot82" You are wise to wait at least until you have read the W&B articles before making any hard decisions about your gear placement. I would take the analysis and recorded data of the articles over any empirical analysis backed up with "it has flown for years that way". When William Wynne was working on my steel tube fuselage, one of the main concerns he had was the fact that the gear was set as it would have been in the 1930's (pre-brakes era), and the gear geometry needed to be reset in order to prevent any chance of nose over on hard braking. You are wise to consider the change. Any curmudgeonly arrows thrown over an issue that you bring up (ultimately the safety of pilot and passenger) should be disregarded. -------- Semper Fi, Terry Hand Athens, GA USMC, USMCR, ATP BVD DVD PDQ BBQ Read this topic online here: http://forums.matronics.com/viewtopic.php?p=420789#420789 ________________________________ Message 14 ____________________________________ Time: 04:55:28 PM PST US From: jim hyde Subject: Re: Pietenpol-List: verbosity he just did.. build it by the plans...otherwise make it longer, wider, encl ose the cockpit, add brakes, skydrol so you have to wear rubber soles, put an elect. systemn i, use metal ribs, and spars, cover it with AL. add an al l glass cockpit, put a PT6 in the nose, long range fuel tanks, a wet bar, m ake room for a copilot, rocket launchers, alone with a tilt wing, etc.=0A =0Athis plane was designed for poor boys what love aviation, want to go slo w , feel the wind, have fun building it, show it off, etc. anything more th an that is a waste of time and money. this guy- needs to build what he wa nts and others should mind their own business-including me.-=0A=0Ajim h yde- m20e taylorcraft, bc12d, Cessna 150 and aircamper owner..-cfi, atp , 737, Cessna citation 747, 747 400 a and p- instructor for future mechan ics, receiver of the Orville and Wilber Wright award. none of which means a nything..=0A=0Abuild it by the plans, use any good glue, put an airworthy A IRPLANE- motor in the nose, use good fabric and paint, -fly it, enjoy i t-and show it off. ________________________________ Message 15 ____________________________________ Time: 05:30:41 PM PST US Subject: Pietenpol-List: Re: CG vs Wheels Location From: "William Wynne" Lorenzo, Everything that you are asking is actually covered in the articles in great depth. Where the axle and where the wing go are not a guess nor a rough estimation, they are now a calculation When building, use this set of steps: 1) Find a plane in the weight and balance data with the same fuselage length and engine you are going to use. 2) Make a calculated mathematical correction to adjust for you specific plane, ie max pilot weight, etc. to make sure that your wing/fuselage relationship keeps the CG between 15" and 20" aft of the leading edge at all loadings. 3) Then, locate the axle from 0 to 3" behind the leading edge if you are using brakes. No Matter what anyone tells you, If you do the above, you are actually Following the plans. My weight and Balance work did not establish any new limits nor axle locations. All I did was follow the data that BHP published in the 1960s. I have had it since getting it with my drawing set from Don P. in 1989. People with brakes, building with the 1930's axle location are actually not following the plans, nor any of the data BHP later developed and published. I have a pile of engineering books and stacks of drawing of classic aircraft. Almost every single bit of data for planes with brakes that have high wings and tail wheels indicated they all have the axle close to the leading edge. Luscombe, Aeronca, Piper, Taylorcraft, Cessna, all of them run it forward, and so did BHP once he got brakes. ------------------------------------------------------ Michael Perez: Keep in mind, I say things plain when safety is in question. Your comments in the letter tell me you are making a mistake, and do not know it. Bluntly, no one needs to move the axle backward. I could not tell from your website what engine you are using, but if is lighter than a 235 Lycoming or you weigh more than 110 pounds dressed, you are creating a plane that will have a terrible aft CG location. Consider ceasing to advise people on what is OK on CG. You may have built your gear already, but if you willfully ignore the content of my W&B data, you will regret it. You offer a lot of DVD's for sale for a guy who is yet to fly his plane. Some people hold that God created the universe, and thus also created Physics, Chemistry and Gravity. They also hold that he is never absent, as long as they are at work. Play by their rules, they are the best and most reliable protection you can get. Try to get around them, and they are merciless. These same people uphold that it is disrespectful to ask to be physically saved by divine intervention when you got in trouble by breaking the rules of the forces God created. Some people believe in luck, but can offer no evidence of it. I have seen many airplane accidents, and every one offers complete proof of Physics Chemistry and Gravity. Some people se it as wreckage, others see it as what happens when people tell God they don't believe in the forces he created. Take your pick. ------------------------------------------------- If a plane needs the axle moved back to lift the tail under power, in all likely hood, what you are seeing is a plane with a seriously aft CG. This is covered in the W&B articles. If a plane is flying at 20" the tail will be heavier for any gear location than one flying in the middle of the range. Aft gear is an invitation to a nose over, but the only thing that makes this rare is the same plane having an aft CG. You don't fix one mistake with a second. The gear on my pit was at the leading edge, the plane could stay in CG with a 290# pilot, I could stand on the brakes with the Corvair at full throttle and lift the tail with a 165# pilot. I started with an 8 degree deck angle and later went to 13. The plane could be 3 pointed 10 mph slower. I Often pilots who report weak ailerons at low speed are forgetting to use enough rudder. Looking over the nose on landing is a very poor technique. Keep in mind that my instructor trained more than 2,000 pilots between 1952 and 2008. Almost all of this was in tail wheels, 2,500 hours of it in Pitts's. He has 12,000 hours...of instruction. If you want to practice for your Piet, learn how to 3 point a J-3 from the rear seat. If your instructor wants to only teach wheel landings, he is giving you only part of a tool set you will need all of one day. -ww Read this topic online here: http://forums.matronics.com/viewtopic.php?p=420798#420798 ________________________________ Message 16 ____________________________________ Time: 05:57:44 PM PST US Subject: Pietenpol-List: Re: verbosity From: "William Wynne" Jim, Very nice resume. Sounds like you have been around planes for a long time. I have not seen that BHP ever had an engine other than a Ford or a Corvair in his personal Air campers, other than a single photo of one that briefly had a Villie radial. Your comment "put an airworthy AIRPLANE motor in the nose" strikes me as interesting. Are you saying BHP didn't build his own plane the right way? He bought his first Corvair engine in 1960. It cost about $500. My guess is that a used $500 A-65 in 1960 frequently could be had with a free used Cub airframe bolted to it as a package deal. I think the man wanted to use a Corvair, I don't think he was trying to save money. He built two new planes in the next decade, both with Corvairs. If someone builds an exact replica of the "Last original", I think he is building arguably by the last and most up to date set of plans. You can't get more original than that.-ww Read this topic online here: http://forums.matronics.com/viewtopic.php?p=420800#420800 ________________________________ Message 17 ____________________________________ Time: 06:00:22 PM PST US Subject: Re: Pietenpol-List: Re: CG vs Wheels Location From: airlion2@gmail.com Hi Terry, I know what USMC, USMCR , and ATP stand for but what does BVD, DVD, PDQ and BBQ mean? Gardiner Sent from my iPad > On Mar 21, 2014, at 6:22 PM, "jarheadpilot82" wrote: > > > You are wise to wait at least until you have read the W&B articles before making any hard decisions about your gear placement. I would take the analysis and recorded data of the articles over any empirical analysis backed up with "it has flown for years that way". > > When William Wynne was working on my steel tube fuselage, one of the main concerns he had was the fact that the gear was set as it would have been in the 1930's (pre-brakes era), and the gear geometry needed to be reset in order to prevent any chance of nose over on hard braking. You are wise to consider the change. Any curmudgeonly arrows thrown over an issue that you bring up (ultimately the safety of pilot and passenger) should be disregarded. > > -------- > Semper Fi, > > Terry Hand > Athens, GA > > USMC, USMCR, ATP > BVD DVD PDQ BBQ > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=420789#420789 > > > > > > > > > > ________________________________ Message 18 ____________________________________ Time: 06:05:04 PM PST US Subject: Re: Pietenpol-List: Re: CG vs Wheels Location From: airlion2@gmail.com Now I think you are pulling my leg. Gardiner Sent from my iPad > On Mar 21, 2014, at 8:59 PM, airlion2@gmail.com wrote: > > Hi Terry, I know what USMC, USMCR , and ATP stand for but what does BVD, DVD, PDQ and BBQ mean? Gardiner > > > > Sent from my iPad > >> On Mar 21, 2014, at 6:22 PM, "jarheadpilot82" wrote: >> >> >> You are wise to wait at least until you have read the W&B articles before making any hard decisions about your gear placement. I would take the analysis and recorded data of the articles over any empirical analysis backed up with "it has flown for years that way". >> >> When William Wynne was working on my steel tube fuselage, one of the main concerns he had was the fact that the gear was set as it would have been in the 1930's (pre-brakes era), and the gear geometry needed to be reset in order to prevent any chance of nose over on hard braking. You are wise to consider the change. Any curmudgeonly arrows thrown over an issue that you bring up (ultimately the safety of pilot and passenger) should be disregarded. >> >> -------- >> Semper Fi, >> >> Terry Hand >> Athens, GA >> >> USMC, USMCR, ATP >> BVD DVD PDQ BBQ >> >> >> >> >> Read this topic online here: >> >> http://forums.matronics.com/viewtopic.php?p=420789#420789 >> >> >> >> >> >> >> >> >> >> ________________________________ Message 19 ____________________________________ Time: 06:06:15 PM PST US From: "Chris" Subject: RE: Pietenpol-List: CG vs Wheels Location The excellent article by Ryan Mueller and William Wynne published in the January 2013 newsletter referenced the correct landing gear placement saying, "The late model plans specify that the axle should only be 0.5" behind the leading edge"(fourth paragraph of the article). This is not on the plans. It is found on an 8.5x11 piece of paper I received with my plans set. This sheet shows the weight and balance computations for a "1966 Pietenpol Air Camper Powered with a 110-66 Corvair Engine". On this it says "D is 0.5 inches back of weighing point" and D is the distance from the main wheel to the datum (leading edge). The fuselage measurement and vintage suggest this is a long fuselage. Also, when I received my plans, I received a 6 page document entitled "Converting the Corvair Engine" by Mr. Pietenpol. On page 1 Mr. Pietenpol lists the empty weight of this airplane using the modified Corvair engine at 622 pounds, which happens to be the same weight as the one on the weight and balance sheet mentioned above. On page two Mr. Pietenpol list the modifications to this plane. The important ones for this discussion are: -fuselage lengthened 9 inches (the genesis of the LONG fuselage) -wings slanted back 3 inches -wheels moved forward 7 inches so that a modified J3 Cub landing gear and brakes could be fitted. Using a little math, if the split axel landing gear legs were built per the plans the axel would be 19 inches from the long fuselage firewall (17 inches for the standard plans fuselage plus 2 inches more for the LONG fuselage extension of the first bay). Then moving the axel forward 7 inches would put it at 19-7= 12 inches back from the firewall. The wing was at 7.5 inches on the standard fuselage plus 2 inches (extension of the first bay) puts the wing at 9.5 inches behind the firewall plus the 3 inch slant puts the wing at 12.5 inches from the firewall. This brings us back to the 0.5 inch measurement but in this case its axel in front of the wing. I'm guessing the J# gear had a slightly different sweep to the gear legs. This modified airplane Mr. Pietenpol speaks of must be the same as the "1966 Pietenpol Air Camper Powered with a 110-66 Corvair Engine" airplane shown on the weight and balance sheet. However, Mr. Pietenpol goes on to say on page 2 that 7 inches was too much. He recommends splitting the difference which would mean the axel should be at 12+3.5=15.5 inches behind the firewall or 3 inches behind the leading edge of this aircrafts wing. Remember he is talking about a long fuselage. Note that this location is behind this particular plane's leading edge. The important factor in the location of the axel that is not mentioned is the CG. If you make sure you operating within the recommended CG envelope I believe the advice would be that your axel placement should not be any farther back than the 3 inches behind the leading edge that Mr. Pietenpol recommends. Background research on landing gear placement shows: -The 1933-34 "Improved Air Camper" plans, no brakes: show the axel to be 17 inches behind the firewall and the wing 7.5 inches behind the firewall. This puts the axel 9.5 inches behind the wings leading edge. -The LONG fuselage adds 2 inches to the first bay so if using the landing gear form the 1933-34 plans it should be at 19 inches behind the firewall and the wing should be at 7.5+2 or 9.5 inches from the firewall. - In the plans: the fuselage drawing with the sample weight and balance shown on the supplemental plan sheet (also showing the tube fuselage) appears to be a 1933-34 plans fuselage but with brakes. Here the axle is shown at 16.5 inches behind the firewall and 5.25 inches behind the leading edge of the wing. -There is no advice for the axel placement on the supplemental plans for the LONG fuselage without brakes. However Chris Bobka did some research and guesswork to figure it should be at 21 inches behind the firewall with no brakes. He did the analysis to help Greg and Dale with their LONG fuselage Pietenpol. Chris reported during flight tests that the placement was right on. I believe Gary Boothe has his long fuselage axel located per the split axel plans. Wing back 4 inches. (Correct me if I am wrong Garry) And it seems to behave fine. - The 4th Quarter 1984 Brodhead Pietenpol newsletter they quote Mr. Pietenpol as saying, the plane is OK with the gear as far forward as it is now, with a note saying he was talking about the last two Corvair powered ships. But unfortunately it does not say where the axel is. Looking at modern high wing planes with tail wheel seem to show main wheel at about the leading edge of the wing. Lastly, in an article about landing gear design published in Sport Aviation by Ladislao Pazmany, he states "The main gear should contact the ground at least 15 degrees ahead of the most forward center of gravity with the aircraft in level attitude." This center of gravity is the CG of the plane and on a parasol plane it is somewhere below the wing. Unfortunately, I don't know where this point is on a Pietenpol. Some have suggested it is about the center of the instrument panel but that is just a guess. As an aside I also found in "Aeronautical Engineering and Airplane Design" published in 1918, the landing gear should be at 13 degrees 10 minutes. It also assumes the CG is the same height as the propeller. Chris T. Sacramento, Ca Westcoastpiet.com From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of larharris2 Harris Sent: Friday, March 21, 2014 2:47 PM Subject: RE: Pietenpol-List: CG vs Wheels Location Thanks, Michael. I have heard from others about "this is what I did." I very much appreciate the all the input from everyone. I'm still waiting for the WW Wt&Bal articles to arrive which may shed some more light on my questioning. And perhaps the curmudgeons will heap abuse on me for even considering deviating from the plans. But I'm looking for some general design guidance on how (where) to locate the gear for a taildragger. Design guidance is pretty standard for allowable CG range, given the Center-of-Lift of the wing (%MAC). I'm beginning to believe that locating the gear may be a matter of trial and error, though. You can't have the wheels too far out ahead of the CG or you will have controllability problems on landing. On the other hand, if you get the wheels too far back, close to the CG, you nose over at the first application of brakes. I understand that others have had just this problem. I think building to the plans will not work for me because I intend to include a wheel brake system. I'd like to hear if there is some range of design limits that I might start with. Or maybe I'll just pick a point others have tried with success & not worry about it. Lorenzo _____ From: speedbrake@sbcglobal.net Subject: Re: Pietenpol-List: Re: Vasek's Pietenpol project Lorenzo, I don't believe I have any NEW thoughts, but I'll tell you my logic for building mine. I believe most of your questions will be answered in the DVD, however, as with the entire series, they detail how I am building my plane and don't reflect the various ways it can be done. There were some extensive tests done and articles written to the news letter about landing gear locations and CG. Those came out after I had my gear built, but still, I am glad I made mine the way I did. If you don't have these articles, it would be well worth the effort to acquire them. Pietenpols are known for being tail heavy. I have been building mine with that in mind and try to keep it light and keep it "balanced" (nose heavy, if you will...) I have talked with Mike Cuy and he informed me that he moved his gear, (wood with the wire wheels) 3" aft from the plans. Mike's plane is extremely nice and has been flying for 15+ years, so I had no issues copying his ideas. Going from memory, that moves the axle about 20" from the firewall. He explained that this allowed the tail to leave the ground early, potentially reducing ground friction and allowing him to get a clear view of the runway out front sooner. I moved my gear back the same 3". With this new location, I set my deck angle to about a 10 deg., maybe less. As Jack noted, I wanted a little higher landing speed to have some better control authority and a shallow approach angle so I can see the runway longer into the landing. Moving the gear back changes the CG, but having built my plane as I have, I don't feel I will have any CG issues at all. I still expect to have near vertical cabanes... If God is your co-pilot...switch seats. Michael Perez Pietenpol HINT Videos Karetaker Aero www.karetakeraero.com ========== st" target="_blank">http://www.matronics.com/Navigator?Pietenpol-List ========== http://forums.matronics.com ========== ="_blank">http://www.matronics.com/contribution ========== ________________________________ Message 20 ____________________________________ Time: 06:06:54 PM PST US From: larharris2 Harris Subject: RE: Pietenpol-List: Re: CG vs Wheels Location WW=2C I very much appreciate your input. I eagerly await the arrival of the articles you authored. You are correct that proper CG location is critical to good controllability in the finished airplane. That's why I have been s uch a pest on the issue. I suspect that you are also right in that many fin ished=2C and unused=2C planes are that way because they scare their owners. I value the DVDs that Michael Perez has put together. I have my set of plan s to use for dimensions=2C etc. And my own standards for workmanship. But M ichael's videos show his perspective on work sequence=2C materials techniqu es=2C and quality of workmanship. I don't do everything the same as he does =2C but=2C lacking a local group to 'show-and-tell' with=2C it is nice to s ee how someone else has approached construction of certain components. Quote from someone else: There are Rules and there are Laws. Rules can be broken=2C Laws (of physics) cannot. ie. The Rule says that you cannot fly under the bridge. If you do fly under the bridge just be sure that you don 't run into it. "If you want to practice for your Piet=2C learn how to 3 point a J-3 from the rear seat." How about a no-flap from the back seat of a T-38? If that counts=2C I'm good to go. :) Lorenzo > > =========== =========== =========== =========== > > > ________________________________ Message 21 ____________________________________ Time: 07:50:54 PM PST US Subject: Pietenpol-List: Re: CG vs Wheels Location From: "Don Emch" Good grief! Please don't over complicate this! Either build the plane without brakes and keep the gear as is or add brakes and move the axle an inch or two forward. It's really that simple!! Now go get your hack saw and light up your torch! Don Emch NX899DE Read this topic online here: http://forums.matronics.com/viewtopic.php?p=420811#420811 ________________________________ Message 22 ____________________________________ Time: 09:55:31 PM PST US Subject: Pietenpol-List: Re: CG vs Wheels Location From: "William Wynne" Don, While Chris does have a long paragraph there, it is some really good research, When we wrote the series, I made note of assistance from a very well researched builder. For the record, it was Chris. His notes here are all numbers, not old stories, thus are useful in the big picture. No builder needs to know all of them, they just need one path that suits their plane. It isn't that complicated. If it takes 1,000 trips to the shop to build your plane, devoting maybe one of them to making a good CG plan makes sense to me. BTW, I think just moving the axle an inch or two is 4" short of BHP's recommendation. Chris, I did a W&B on the last Original in 2007. The axle is near the leading edge. The only 'cub' parts to the gear are the wheels, axle size, and tires. I am pretty sure it does not have brakes. I would like to do it and the plane at Pioneer (the 1966) again this year. I think they are physical examples of how BHP thought the design was 'optimal.' -ww Read this topic online here: http://forums.matronics.com/viewtopic.php?p=420813#420813 ________________________________ Message 23 ____________________________________ Time: 10:05:46 PM PST US From: "Gary Boothe" Subject: RE: Pietenpol-List: CG vs Wheels Location ".I believe Gary Boothe has his long fuselage axel located per the split axel plans. Wing back 4 inches. (Correct me if I am wrong Gary) And it seems to behave fine.." You're correct. Plane behaves fine.It's me who behaves badly. Gary Boothe NX308MB From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of Chris Sent: Friday, March 21, 2014 6:06 PM Subject: RE: Pietenpol-List: CG vs Wheels Location The excellent article by Ryan Mueller and William Wynne published in the January 2013 newsletter referenced the correct landing gear placement saying, "The late model plans specify that the axle should only be 0.5" behind the leading edge"(fourth paragraph of the article). This is not on the plans. It is found on an 8.5x11 piece of paper I received with my plans set. This sheet shows the weight and balance computations for a "1966 Pietenpol Air Camper Powered with a 110-66 Corvair Engine". On this it says "D is 0.5 inches back of weighing point" and D is the distance from the main wheel to the datum (leading edge). The fuselage measurement and vintage suggest this is a long fuselage. Also, when I received my plans, I received a 6 page document entitled "Converting the Corvair Engine" by Mr. Pietenpol. On page 1 Mr. Pietenpol lists the empty weight of this airplane using the modified Corvair engine at 622 pounds, which happens to be the same weight as the one on the weight and balance sheet mentioned above. On page two Mr. Pietenpol list the modifications to this plane. The important ones for this discussion are: -fuselage lengthened 9 inches (the genesis of the LONG fuselage) -wings slanted back 3 inches -wheels moved forward 7 inches so that a modified J3 Cub landing gear and brakes could be fitted. Using a little math, if the split axel landing gear legs were built per the plans the axel would be 19 inches from the long fuselage firewall (17 inches for the standard plans fuselage plus 2 inches more for the LONG fuselage extension of the first bay). Then moving the axel forward 7 inches would put it at 19-7= 12 inches back from the firewall. The wing was at 7.5 inches on the standard fuselage plus 2 inches (extension of the first bay) puts the wing at 9.5 inches behind the firewall plus the 3 inch slant puts the wing at 12.5 inches from the firewall. This brings us back to the 0.5 inch measurement but in this case its axel in front of the wing. I'm guessing the J# gear had a slightly different sweep to the gear legs. This modified airplane Mr. Pietenpol speaks of must be the same as the "1966 Pietenpol Air Camper Powered with a 110-66 Corvair Engine" airplane shown on the weight and balance sheet. However, Mr. Pietenpol goes on to say on page 2 that 7 inches was too much. He recommends splitting the difference which would mean the axel should be at 12+3.5=15.5 inches behind the firewall or 3 inches behind the leading edge of this aircrafts wing. Remember he is talking about a long fuselage. Note that this location is behind this particular plane's leading edge. The important factor in the location of the axel that is not mentioned is the CG. If you make sure you operating within the recommended CG envelope I believe the advice would be that your axel placement should not be any farther back than the 3 inches behind the leading edge that Mr. Pietenpol recommends. Background research on landing gear placement shows: -The 1933-34 "Improved Air Camper" plans, no brakes: show the axel to be 17 inches behind the firewall and the wing 7.5 inches behind the firewall. This puts the axel 9.5 inches behind the wings leading edge. -The LONG fuselage adds 2 inches to the first bay so if using the landing gear form the 1933-34 plans it should be at 19 inches behind the firewall and the wing should be at 7.5+2 or 9.5 inches from the firewall. - In the plans: the fuselage drawing with the sample weight and balance shown on the supplemental plan sheet (also showing the tube fuselage) appears to be a 1933-34 plans fuselage but with brakes. Here the axle is shown at 16.5 inches behind the firewall and 5.25 inches behind the leading edge of the wing. -There is no advice for the axel placement on the supplemental plans for the LONG fuselage without brakes. However Chris Bobka did some research and guesswork to figure it should be at 21 inches behind the firewall with no brakes. He did the analysis to help Greg and Dale with their LONG fuselage Pietenpol. Chris reported during flight tests that the placement was right on. I believe Gary Boothe has his long fuselage axel located per the split axel plans. Wing back 4 inches. (Correct me if I am wrong Garry) And it seems to behave fine. - The 4th Quarter 1984 Brodhead Pietenpol newsletter they quote Mr. Pietenpol as saying, the plane is OK with the gear as far forward as it is now, with a note saying he was talking about the last two Corvair powered ships. But unfortunately it does not say where the axel is. Looking at modern high wing planes with tail wheel seem to show main wheel at about the leading edge of the wing. Lastly, in an article about landing gear design published in Sport Aviation by Ladislao Pazmany, he states "The main gear should contact the ground at least 15 degrees ahead of the most forward center of gravity with the aircraft in level attitude." This center of gravity is the CG of the plane and on a parasol plane it is somewhere below the wing. Unfortunately, I don't know where this point is on a Pietenpol. Some have suggested it is about the center of the instrument panel but that is just a guess. As an aside I also found in "Aeronautical Engineering and Airplane Design" published in 1918, the landing gear should be at 13 degrees 10 minutes. It also assumes the CG is the same height as the propeller. Chris T. Sacramento, Ca Westcoastpiet.com From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com] On Behalf Of larharris2 Harris Sent: Friday, March 21, 2014 2:47 PM Subject: RE: Pietenpol-List: CG vs Wheels Location Thanks, Michael. I have heard from others about "this is what I did." I very much appreciate the all the input from everyone. I'm still waiting for the WW Wt&Bal articles to arrive which may shed some more light on my questioning. And perhaps the curmudgeons will heap abuse on me for even considering deviating from the plans. But I'm looking for some general design guidance on how (where) to locate the gear for a taildragger. Design guidance is pretty standard for allowable CG range, given the Center-of-Lift of the wing (%MAC). I'm beginning to believe that locating the gear may be a matter of trial and error, though. You can't have the wheels too far out ahead of the CG or you will have controllability problems on landing. On the other hand, if you get the wheels too far back, close to the CG, you nose over at the first application of brakes. I understand that others have had just this problem. I think building to the plans will not work for me because I intend to include a wheel brake system. I'd like to hear if there is some range of design limits that I might start with. Or maybe I'll just pick a point others have tried with success & not worry about it. Lorenzo _____ From: speedbrake@sbcglobal.net Subject: Re: Pietenpol-List: Re: Vasek's Pietenpol project Lorenzo, I don't believe I have any NEW thoughts, but I'll tell you my logic for building mine. I believe most of your questions will be answered in the DVD, however, as with the entire series, they detail how I am building my plane and don't reflect the various ways it can be done. There were some extensive tests done and articles written to the news letter about landing gear locations and CG. Those came out after I had my gear built, but still, I am glad I made mine the way I did. If you don't have these articles, it would be well worth the effort to acquire them. Pietenpols are known for being tail heavy. I have been building mine with that in mind and try to keep it light and keep it "balanced" (nose heavy, if you will...) I have talked with Mike Cuy and he informed me that he moved his gear, (wood with the wire wheels) 3" aft from the plans. Mike's plane is extremely nice and has been flying for 15+ years, so I had no issues copying his ideas. Going from memory, that moves the axle about 20" from the firewall. He explained that this allowed the tail to leave the ground early, potentially reducing ground friction and allowing him to get a clear view of the runway out front sooner. I moved my gear back the same 3". With this new location, I set my deck angle to about a 10 deg., maybe less. As Jack noted, I wanted a little higher landing speed to have some better control authority and a shallow approach angle so I can see the runway longer into the landing. Moving the gear back changes the CG, but having built my plane as I have, I don't feel I will have any CG issues at all. I still expect to have near vertical cabanes... If God is your co-pilot...switch seats. Michael Perez Pietenpol HINT Videos Karetaker Aero www.karetakeraero.com ========== st" target="_blank">http://www.matronics.com/Navigator?Pietenpol-List ========== http://forums.matronics.com ========== ="_blank">http://www.matronics.com/contribution ========== http://www.matronics.com/Navigator?Pietenpol-List http://forums.matronics.com http://www.matronics.com/contribution ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message pietenpol-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/Pietenpol-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/pietenpol-list Browse Digests http://www.matronics.com/digest/pietenpol-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.