Brodhead Pietenpol Association

Original Posted By: "Cuy, Michael D. (GRC-LME0)[Vantage Partners, LLC]"
After doing quite a bit of Pietenpol flying and after flying several different Pietnepols both with and without passengers and Pietswith various engines and empty weights (including a 75hp Grega), you really aren't limited by whatever number you choose to be callyour gross weight on your placard as much as you are the basic practicalities of flight and the laws of nature. You can carry a lot heavier passenger on a 40F day thanyou can an 85F day. You might be able to give young person a ride out of an 1,800' grass strip with trees on both ends but you wouldn't beable to take an adult out of the same strip.One thing I know for sure is that Bill Rewey was able to give a LOT of rides to all kinds of people even on hot days with his little 65HP Pietenpol simply because hebuilt his Piet with a longer wing. (can't recall how many extra feet but a few) The Pietenpol has roughly 6 feet less wingspan than a Cub or a Champ ( I know, squarefootage is the exact number but you get the idea) and I have seen (and flown) Cubs and Champs with some very large passengers when I would never, ever considertaking those same people up in my Piet on a given day.If you live in Denver you won't be able to fly with as much of a load as you would if you were based at an airport closer to sea level. You might beable to carry a full load of fuel and no passenger or 10 gallons of fuel and an adult and such so for me the gross, safe takeoff weight of a Piet is determinedby those thing for the particular day, airport, Pietenpol, and wind and elevation and temperature conditions.Mike C.Ohio________________________________________________________________________________

Original Posted By: michael.d.cuy(at)nasa.gov
Good to know about Bill Rewey's as this is the only thing I would consider changing. I have a lot of experience in a particular short wing piper on floats and it made a great speed boat at times. A super cub at the same weight would fly circles around it with the same hp. I'm just not sure I feel comfortable with the engineering.Doug Dever=0AIn beautiful Stow Ohio

Original Posted By: "Braniff1966"
My spars are 3/4" solid spruce with 1X1/8" plywood strips glued to each side along the top and bottom of the spars, creating a 1" thick spar on the top and bottom edges. Wings are complete, not covered.Hope this is of any use,Ray KrauseSkyScout building in progressSent from my iPad> On Jul 31, 2014, at 7:33 AM, Michael Perez wrote:> > Oscar, I'm not sure if you are looking for a database of wing spar thicknesses being used, however, if you are...NX992WD uses 3/4" solid spruce.> > If God is your co-pilot, switch seats> Mike Perez> Karetaker Aero> Working W.& B. Numbers> > > 3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D=3D> ________________________________________________________________________________Subject: Pietenpol-List: Re: spar strength

Original Posted By: "jarheadpilot82"
jim bdont confuse these people with real facts.. they want to sit arond and yap aboutalready decided things.. if they are worried about the wing just increase thestrut diameter and double the jury struts..my plane has a 1 inch spar no routingon a three piece wing.....jim hydeRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: gross weight----it is all relative

Original Posted By: Jim Boyer
Mike,I understand what you are saying about different Density Altitudes, payloads, temperatures,etc. affecting the airplanes you have flown. However, I don't thinkthat the most recent discussion primarily led by Oscar has been about thatat all. His discussion has been about max gross weight determined based upon designstrength, not performance capability.For example, If you wanted to build a really light Pietenpol you could probablesave some weight by putting in 1/2 inch thick spars (maybe even 1/4 inch!) andit would be lighter. But I am guessing that the spars would fail at far lessthan the suggested 1080 pound gross weight. That would happen whether it wasMarch, or July, Colorado or Florida. It would not matter if it was a standardday of 59 degrees or 102 degrees. The spars would likely fail. Not because ofthe performance that day, but based upon design strength.I am not an aerodynamicist, nor did I sleep in a Holiday Inn Express last night,but I do think that we are speaking about 2 different things.--------Semper Fi,Terry HandAthens, GAUSMC, USMCR, ATPBVD DVD PDQ BBQRead this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Thu, 31 Jul 2014 21:39:02 +0000 (UTC)

Original Posted By: Jim Boyer

Original Posted By: danhelsper(at)aol.com
That makes perfect sense Terry and I see the perspective that Oscar is coming from. I was looking at gross weight from the other end of the spectrum but I completely see whereOscar is coming from, yes---good points. The neat thing about the Pietenpol accident record database is that (unless I missed it) there's no record of a structural wing failure which issuch a tribute to the Piet design given that there have been some white-pine and Elmer's Carpenter glue Piets built and flown out there:) ! I was so amazed at the severe jolting I tookon my 2005 return trip from WI to OH and that the airplane acted like nothing to it even though I prayed all the way home:) !Mike C.Mike,I understand what you are saying about different Density Altitudes, payloads, temperatures, etc. affecting the airplanes you have flown. However, I don't think that the most recent discussion primarily led by Oscar has been about that at all. His discussion has been about max gross weight determined based upon design strength, not performance capability.For example, If you wanted to build a really light Pietenpol you could probable save some weight by putting in 1/2 inch thick spars (maybe even 1/4 inch!) and it would be lighter. But I am guessing that the spars would fail at far less than the suggested 1080 pound gross weight. That would happen whether it was March, or July, Colorado or Florida. It would not matter if it was a standard day of 59 degrees or 102 degrees. The spars would likely fail. Not because of the performance that day, but based upon design strength.I am not an aerodynamicist, nor did I sleep in a Holiday Inn Express last night, but I do think that we are speaking about 2 different things.--------Semper Fi,Terry HandAthens, GAUSMC, USMCR, ATPBVD DVD PDQ BBQRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Re: Pietenpol-List: Re: spar strength

Original Posted By:iginal Message-----=0A Gene Rambo =0ATo: piete
I STILL haven't filled-in the data plate with a gross weight!=0A=0A=0ADan Helsper=0ALoensloe Airfield=0APuryear, TN=0A=0A=0A=0A-----Or

Original Posted By: "taildrags"
I have that T shirt as well, Mike. --------Semper Fi,Terry HandAthens, GAUSMC, USMCR, ATPBVD DVD PDQ BBQRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: spar strength

Original Posted By: Gene Rambo
Jim B.-The important characteristic of a beam's ability to resist bending is the sectionmodulus. For a rectangular beam, the section modulus varies as the *square*of the height of the beam. If you double the height of a beam, you don't justdouble its section modulus, you make it four times greater. The Air Campermain spar is 4-3/4" tall, but the Piper Cub main spar is 6-1/4" tall. From this,you can see that the Cub spar can be less thick than the 1" Air Camper sparbut still have comparable strength in bending.I don't know what the Champ spar dimensions are, but my guess is that they arealso taller than those of the Air Camper.--------Oscar ZunigaMedford, ORAir Camper NX41CC "Scout"A75 powerRead this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Re: Pietenpol-List: Re: spar strength

Original Posted By: larharris2 Harris
Aaaaaaaaaaaarrrrrrrrrrrrgggggggggggghhhhhhhhhh!!!!!!!!GeneOn Jul 31, 2014, at 6:57 PM, "taildrags" wrote:> > Jim B.-> > The important characteristic of a beam's ability to resist bending is the sectionmodulus. For a rectangular beam, the section modulus varies as the *square*of the height of the beam. If you double the height of a beam, you don'tjust double its section modulus, you make it four times greater. The Air Campermain spar is 4-3/4" tall, but the Piper Cub main spar is 6-1/4" tall. Fromthis, you can see that the Cub spar can be less thick than the 1" Air Camperspar but still have comparable strength in bending.> > I don't know what the Champ spar dimensions are, but my guess is that they arealso taller than those of the Air Camper.> > --------> Oscar Zuniga> Medford, OR> Air Camper NX41CC "Scout"> A75 power> > > > > Read this topic online here:> > http://forums.matronics.com/viewtopic.p ... 656#427656> > > > > > > > > > > ________________________________________________________________________________

Original Posted By:Airfield=0APuryear, TN=0A=0A=0A=0A-----Original Message-----=0A larha
All this talk about setting the Gross weight limit.......it is a mute point once you finish your airplane and start to fly. The number is meaningless. The only important number I consider is "how much the passenger weighs, and how hot of a day is it? And maybe how much fuel do I have? When somebody walks up to you at Brodhead and asks for a ride, I don't break out the slide rule for calculations. It is just an eyeball estimate, mostly based on how chunky the potential passenger looks, and how much svinkter it took to get the previous passenger into the air.=0A=0A=0ADan Helsper=0ALoensloe

Original Posted By: Michael Perez

Original Posted By: Michael Perez

Original Posted By: "tools"
Agree. Those that are not interested can skip over the thread.Read this topic online here:http://forums.matronics.com/viewtopic.p ... ___Subject: Pietenpol-List: Re: gross weight----it is all relative

Original Posted By: "Douwe Blumberg"
Dan,Actually it is not a moot point at all.When you got your aircraft inspected by the FAA, you had to indicate a maximumgross weight. Hopefully you used something more that a couple of bathroom scalesto determine your aircrafts empty weight.You are correct that you should not have to break out a slide rule every time youdecide to go flying. That is because you broke out the slide rule early on,and did precise computations to determine your C.G. range. Now you can decidebased upon those computations that you can only take an 80 pound kid in the frontseat before you are flying out of the proper C.G. range, or you are ableto take a 250 pound fat body with no problem.Then you can take a look at your density altitude and runway length to determinewhether or not it is safe to take the fat body flying, or the conditions aresuch that it is not even wise to take the 80 pound kid flying. If you are outwest you may even find that you cant carry yourself and a full bag of gas. Butyou know all of this because you did do the slide rule work early on.This is not meant to insult your intelligence, Dan. I am sure that you alreadyknow this and do it on a regular basis. But we do have some newly-minted pilotson this forum as well as guys that are still taking lessons. They need to knowthis and develop good habits early on in managing risk.I can assure you that if you dont ask your self these questions before you fly,the FAA will ask you these questions if you have an incident. What was your calculatedtakeoff weight? What was the density altitude and runway length? Wereyou in the proper C.G. range when you took off? Its ask now, or possibly beasked later.--------Semper Fi,Terry HandAthens, GAUSMC, USMCR, ATPBVD DVD PDQ BBQRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________

Original Posted By: Ray Krause
=0A=0A=0A=0A=0A=0A=0A=0AAfter doing quite a bit of Pietenpol flying and after flying several different Pietnepols both with and without passengers and Piets=0Awith various engines and empty weights (including a 75hp Grega)=2C you really aren=92t limited by whatever number you choose to be call=0Ayour gross weight on your placard as much as you are the basic practicalities of flight and the laws of nature. You can carry a lot heavier passenger on a 40F day than=0Ayou can an 85F day. You might be able to give young person a ride out of an 1=2C800=92 grass strip with trees on both ends but you wouldn=92t be=0A=0Aable to take an adult out of the same strip. =0A =0AOne thing I know for sure is that Bill Rewey was able to give a LOT of rides to all kinds of people even on hot days with his little 65HP Pietenpol simply because he=0Abuilt his Piet with a longer wing. (can=92t recall how many extra feet but a few) The Pietenpol has roughly 6 feet less wingspan than a Cub or a Champ ( I know=2C square=0Afootage is the exact number but you get the idea) and I have seen (and flown) Cubs and Champs with some very large passengers when I would never=2C ever consider=0Ataking those same people up in my Piet on a given day. =0A=0A =0AIf you live in Denver you won=92t be able to fly with as much of a load as you would if you were based at an airport closer to sea level. You might be=0Aable to carry a full load of fuel and no passenger or 10 gallons of fuel and an adult and such so for me the gross=2C safe takeoff weight of a Piet is determined=0Aby those thing for the particular day=2C airport=2C Pietenpol=2C and wind and elevation and temperature conditions. =0A=0A =0AMike C.=0AOhio=0A =0A =0A =0A=0A=0A=0A=0A=0A=0A============0A============0A============0A============0A=0A ________________________________________________________________________________