---------------------------------------------------------- Pietenpol-List Digest Archive --- Total Messages Posted Tue 09/16/03: 15 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:27 AM - Re: CG was Useful Weight (Robert Haines) 2. 07:03 AM - Re: Useful Weight (Robert Haines) 3. 08:12 AM - Re: Re: Useful Weight (Ed Grentzer) 4. 08:18 AM - Re: Re: Useful Weight (Mike) 5. 08:34 AM - Re: Re: Useful Weight (Robert Gow) 6. 08:41 AM - Re: Useful Weight (John Dilatush) 7. 12:30 PM - S.A. Magazines...old (Jim Vydra) 8. 02:47 PM - Yet another Pietenpol magazine article.... (Jim Markle) 9. 03:45 PM - Re: Re: Useful Weight (JamesJboyer@aol.com) 10. 04:46 PM - Re: Re: Useful Weight (Jim Markle) 11. 07:55 PM - prop (Richard Navratil) 12. 07:59 PM - Re: Re: Useful Weight (DOUGLAS BLACKBURN) 13. 09:16 PM - Re: prop (Christian Bobka) 14. 09:58 PM - Re: Re: Useful Weight (JamesJboyer@aol.com) 15. 10:01 PM - Re: Re: Useful Weight (JamesJboyer@aol.com) ________________________________ Message 1 _____________________________________ Time: 06:27:51 AM PST US From: "Robert Haines" Subject: Re: Pietenpol-List: CG was Useful Weight --> Pietenpol-List message posted by: "Robert Haines" Why would having a longer nose cause you have problems recovering from a slip? My guess is that the extra nose would act counter to the rudder in a slip and help keep it there, simple due to the fact that the side surface area of the nose is forward of the center of lift. Somewhat like if the aircraft was hanging by a string at the center of lift, a crosswind hitting the tail would try to rotate the aircraft one way, the same wind hitting the nose would try to rotate the aircraft the other. A longer nose provide a higher ratio of surface in front of to surface behind the center of lift. If this is the case, moving the wing back does the exact same thing, so is there really a problem? Robert Haines Up here in beautiful Illinois hopeing that Corky eventually flys his own plane. ________________________________ Message 2 _____________________________________ Time: 07:03:22 AM PST US From: "Robert Haines" Subject: Pietenpol-List: Re: Useful Weight --> Pietenpol-List message posted by: "Robert Haines" One of the tech counselors on this list may help out with this one, I'm sure I don't know all the regulations as well as I think. Gross weight rating is a function of ultimate load (in "g") and the force required to fail the structure. For certified aircraft, the design criteria for the utility class is a minimum rated load of 4.4g positive and something I can't remember for negative, among other things. This rated load is a function of ultimate load, which is simply a safety factor (ultimate load is 1.5 times rated, 2.0 times for fiberglass construction). So the first thing you need to know is how much load will the structure handle before failing. Let's say the at 6,000lbs of force, the weakest part fails (motor mount, struts, fuselage, whatever). If we are trying to certify our aircraft in the utility category we need 6.6g ultimate to rate at 4.4g (4.4 x 1.5 = 6.6), so our gross weight becomes 6000/6.6 or 909lbs. Since we are not trying to certify the aircraft in the normal, utility, or aerobatic classes (or categories?), we can set the rated load and gross weight at whatever we wish. Just understand that the two still have to work out with the formula above. In the example, it could be 3.0g (4.5g ultimate) at 1333lbs, or 6.0g (9g ultimate) at 667lbs. Unfortunately, I don't think we know the ultimate load capacity on the aircraft so it makes it a little tough to do this. My guess is that most people just pick a gross weight and live with the fact that the actual rated load is unknown. Robert Haines Du Quoin, Illinois P.S. - You'll notice is used the word "guess" a few times. If anyone else knows this topic a little better, please ring in. ________________________________ Message 3 _____________________________________ Time: 08:12:52 AM PST US From: "Ed Grentzer" Subject: Re: Pietenpol-List: Re: Useful Weight --> Pietenpol-List message posted by: "Ed Grentzer" While picking a gross weight bear in mind that the max gross for the Sport Pilot rule is 1232# if I'm remembering that right. If you pick a gross weight of say 1250# and later lose your medical you could be screwed over 18#s. Or maybe someday someone might want to buy the plane to fly under the Sport Pilot rule. I know this doesn't affect the fellow from S. Africa but here in the U.S. it is now definetly something to consider. Cheers Ed G. >From: "Robert Haines" >Reply-To: pietenpol-list@matronics.com >To: >Subject: Pietenpol-List: Re: Useful Weight >Date: Tue, 16 Sep 2003 09:03:11 -0500 > >--> Pietenpol-List message posted by: "Robert Haines" > > >One of the tech counselors on this list may help out with this one, I'm >sure >I don't know all the regulations as well as I think. > >Gross weight rating is a function of ultimate load (in "g") and the force >required to fail the structure. For certified aircraft, the design >criteria >for the utility class is a minimum rated load of 4.4g positive and >something >I can't remember for negative, among other things. This rated load is a >function of ultimate load, which is simply a safety factor (ultimate load >is >1.5 times rated, 2.0 times for fiberglass construction). > >So the first thing you need to know is how much load will the structure >handle before failing. Let's say the at 6,000lbs of force, the weakest >part >fails (motor mount, struts, fuselage, whatever). If we are trying to >certify our aircraft in the utility category we need 6.6g ultimate to rate >at 4.4g (4.4 x 1.5 = 6.6), so our gross weight becomes 6000/6.6 or 909lbs. > >Since we are not trying to certify the aircraft in the normal, utility, or >aerobatic classes (or categories?), we can set the rated load and gross >weight at whatever we wish. Just understand that the two still have to >work >out with the formula above. In the example, it could be 3.0g (4.5g >ultimate) at 1333lbs, or 6.0g (9g ultimate) at 667lbs. Unfortunately, I >don't think we know the ultimate load capacity on the aircraft so it makes >it a little tough to do this. My guess is that most people just pick a >gross weight and live with the fact that the actual rated load is unknown. > > >Robert Haines >Du Quoin, Illinois > >P.S. - You'll notice is used the word "guess" a few times. If anyone else >knows this topic a little better, please ring in. > > Compare Cable, DSL or Satellite plans: As low as $29.95. https://broadband.msn.com ________________________________ Message 4 _____________________________________ Time: 08:18:39 AM PST US Subject: Re: Pietenpol-List: Re: Useful Weight From: Mike --> Pietenpol-List message posted by: Mike In addition to structural requirements, certificated airplanes have to meet some performance guidelines. FAR part 23, sub part 65 (14 CFR 23.65) says that each "normal, utility, and acrobatic category reciprocating engine-powered airplane of 6,000 pounds or less maximum weight" (that would include Piets if we were seeking certification) "must have a steady climb gradient at sea level of at least 8.3 percent for landplanes or 6.7 percent for seaplanes and amphibians with ...a climb speed ... not less than 1.2 VS1 (stall speed) for single--engine airplanes." Stall speed depends on maximum lift coefficient, wing area, weight and air density. BHP's airfoil was good for about a 1.3-1.4 maximum lift coefficient on the 145 square foot wing, most Piets seem to be flown at a max gross of around 1100 Lb, and we assume sea level density (0.0765 Lbm per cubic foot). Most of our birds will stall around 45 mph TAS. 1.2 times that is 54 mph. 8.3% of that is a little over 390 feet per minute. So, at or above 54 mph we would have to be light enough (and powerful enough) to climb at 390 fpm at the gross weight we used for the stall calculation. If we can't do that, we would have to get bigger engines or reduce our maximum weight. Since we are not seeking certification, these are just guidelines, but they are a pretty good indicator of whether we are doing things right. Mike Hardaway on 9/16/03 7:03, Robert Haines at robertsjunk@hotmail.com wrote: > --> Pietenpol-List message posted by: "Robert Haines" > > > One of the tech counselors on this list may help out with this one, I'm sure > I don't know all the regulations as well as I think. > > Gross weight rating is a function of ultimate load (in "g") and the force > required to fail the structure. For certified aircraft, the design criteria > for the utility class is a minimum rated load of 4.4g positive and something > I can't remember for negative, among other things. This rated load is a > function of ultimate load, which is simply a safety factor (ultimate load is > 1.5 times rated, 2.0 times for fiberglass construction). > > So the first thing you need to know is how much load will the structure > handle before failing. Let's say the at 6,000lbs of force, the weakest part > fails (motor mount, struts, fuselage, whatever). If we are trying to > certify our aircraft in the utility category we need 6.6g ultimate to rate > at 4.4g (4.4 x 1.5 = 6.6), so our gross weight becomes 6000/6.6 or 909lbs. > > Since we are not trying to certify the aircraft in the normal, utility, or > aerobatic classes (or categories?), we can set the rated load and gross > weight at whatever we wish. Just understand that the two still have to work > out with the formula above. In the example, it could be 3.0g (4.5g > ultimate) at 1333lbs, or 6.0g (9g ultimate) at 667lbs. Unfortunately, I > don't think we know the ultimate load capacity on the aircraft so it makes > it a little tough to do this. My guess is that most people just pick a > gross weight and live with the fact that the actual rated load is unknown. > > > Robert Haines > Du Quoin, Illinois > > P.S. - You'll notice is used the word "guess" a few times. If anyone else > knows this topic a little better, please ring in. > ________________________________ Message 5 _____________________________________ Time: 08:34:08 AM PST US From: "Robert Gow" Subject: RE: Pietenpol-List: Re: Useful Weight --> Pietenpol-List message posted by: "Robert Gow" Pull up FAR 23 on the FAA website and review the paragraphs referring to ground and flight loads, factor of safety and so forth. Flight dynamics figure into the mix - there are accelerations due to yawing and pitching that case loads for fixed masses such as the engine. It's not all just a matter of static strength. Bob -----Original Message----- From: owner-pietenpol-list-server@matronics.com [mailto:owner-pietenpol-list-server@matronics.com]On Behalf Of Robert Haines Subject: Pietenpol-List: Re: Useful Weight --> Pietenpol-List message posted by: "Robert Haines" One of the tech counselors on this list may help out with this one, I'm sure I don't know all the regulations as well as I think. Gross weight rating is a function of ultimate load (in "g") and the force required to fail the structure. For certified aircraft, the design criteria for the utility class is a minimum rated load of 4.4g positive and something I can't remember for negative, among other things. This rated load is a function of ultimate load, which is simply a safety factor (ultimate load is 1.5 times rated, 2.0 times for fiberglass construction). So the first thing you need to know is how much load will the structure handle before failing. Let's say the at 6,000lbs of force, the weakest part fails (motor mount, struts, fuselage, whatever). If we are trying to certify our aircraft in the utility category we need 6.6g ultimate to rate at 4.4g (4.4 x 1.5 = 6.6), so our gross weight becomes 6000/6.6 or 909lbs. Since we are not trying to certify the aircraft in the normal, utility, or aerobatic classes (or categories?), we can set the rated load and gross weight at whatever we wish. Just understand that the two still have to work out with the formula above. In the example, it could be 3.0g (4.5g ultimate) at 1333lbs, or 6.0g (9g ultimate) at 667lbs. Unfortunately, I don't think we know the ultimate load capacity on the aircraft so it makes it a little tough to do this. My guess is that most people just pick a gross weight and live with the fact that the actual rated load is unknown. Robert Haines Du Quoin, Illinois P.S. - You'll notice is used the word "guess" a few times. If anyone else knows this topic a little better, please ring in. ________________________________ Message 6 _____________________________________ Time: 08:41:15 AM PST US From: "John Dilatush" Subject: Re: Pietenpol-List: Useful Weight --> Pietenpol-List message posted by: "John Dilatush" ----- Original Message ----- From: "Deon Engelmann" Subject: Pietenpol-List: Useful Weight > --> Pietenpol-List message posted by: "Deon Engelmann" ++++++++++++++++++++++++++++ Deon, I built my Piet especially for high altitude operation since I live at about 7200 feet and have it based at an airport that is 7946 feet high. We have the continental divide (14000 plus)on one side and 11,000 foot mountains on the other side of our little valley. I was told when I started the project, that most Piets tend toward being tail heavy in their stock form, therefore I felt that I could use a heavier powerplant than the Model A installation. This allowed me a greater range of options for an engine. Since a normally aspirated engine loses about 3% of it's power for each 1000 feet in altitude, this would amount to a 30% loss in power up here. In contrast, a turbo or supercharged engine will develop sea level horsepower up here. Therefore, I am using a Subaru EA-82 turbocharged engine which seems to be developing somewhere between 110 to 135 horsepower here depending on my throttle setting. At take off the engine is pulling 45 inches of manifold pressure. The propeller is a special design that Duane Woolsey gave me, it is an 80" x 52" with a wide chord blade. The reduction unit is a 2.35 to 1.00 ratio, so when the engine is turning 4800 to 5500 rpm the prop is only turning at 2042 to 2340 rpm. I cruise at about 4100 engine rpm which translates to 1744 prop rpm, which is about the same speed as the original Model A engine. This was what I wanted, to match the airframe that Mr. Pietenpol designed. The airframe is completely stock from the firewall back. However, since I added brakes, extra fuel tank, tailwheel, tow hook, ELT, upholstery and other goodies and with the extra engine weight because of the reduction unit, my empty weight with oil and coolant is about 800 lbs. Now, as to performance at this altitude: Last winter with the ground temper ature at 50 degrees F: 10,000 feet I recorded over 1,100 fpm rate of climb 11,000 feet it had dropped off to 1,000 fpm: 12,000 feet I was so darned cold that I could hardly write, but it was still climbing strongly and I can't read my writing! I have had the plane up to 15,300 feet. These numbers were developed with a gross weight of about 1,011 pounds (pilot at 175 lbs and fuel at about 36 lbs). You can placard the plane at any gross weight you would like, I did mine at 1,225 lbs because when I sell it, I wanted it to fit into the Sport Pilot category. As you can see, the actual gross wt. will be higher with full fuel and passenger. The only caution here is not to do any aerobatics when you have the plane fully loaded up. Take off run seems to be quick, and, surprisingly even with full tanks and a passenger, the performance is good. I have not recorded any of these numbers. As you can tell, I am a strong supporter of turbo'd engines for performance at high altitudes. You won't go much faster, but you will have excellent climb and take off characteristics. It handles in the air just like a little fighter. Oscar Zuniga came by a couple of months ago and took pictures of the plane and then posted them with a write up on his web site at http://www.flysquirrel.net/piets/john_piet.html Good luck on your project, I know you will enjoy it. The dreaming stage is part of the fun of building. Cordially, John NX114D ++++++++++++++++++++++++++++++ > > Hi all > > I've been lurking for quite a while on this list as the Pietenpol is one > of my favorite airplanes. It is the simplicity and back to basics of the > airplane that keeps on drawing me back to it. > > I need to make a decision for or against building the Pietenpol. > What I need to know is the useful weight of the aircraft as I've seen > everything from 610 lb empty with 385lb useful (995 lb max) to 535 lb > empty with 715 lb useful (1250 lb max). I weight in at 260lb and my wife > at 120. That does not leave much over for fuel if useful weight is only > 385 lb. ;-) > > My home airport is at 5330 feet above sea level. If I build the > Pietenpol it will have an O-200 in to compensate for altitude. (Model A > fords are very scarce in South Africa.) > > I would appreciate any comments Thanx > > Deon Engelmann > EAA322 Midrand # SA12055 > Pretoria > South Africa > > ________________________________ Message 7 _____________________________________ Time: 12:30:28 PM PST US From: Jim Vydra Subject: Pietenpol-List: S.A. Magazines...old --> Pietenpol-List message posted by: Jim Vydra Hi all, I just listed 3 complete years of S.A. on ebay....1962...1963..and 1969 ________________________________ Message 8 _____________________________________ Time: 02:47:03 PM PST US From: "Jim Markle" Subject: Pietenpol-List: Yet another Pietenpol magazine article.... --> Pietenpol-List message posted by: "Jim Markle" Found another interesting Pietenpol article. This time in an April 1990 issue of a magazine called "Skyways" The Journal of the Airplane 1920-1940 Scanned it and saved it to: http://www.mykitplane.com/Taxiway/TheHangar/photoAlbumManager.cfm?AlbumID=14 5 If anyone wants a larger, possible more readable file, email me direct and I'll send a zipped copy. (If your browser automatically resizes images the picture will be a little small. Turn off auto resize and it's easily readable....) Jim in Plano...... ________________________________ Message 9 _____________________________________ Time: 03:45:41 PM PST US From: JamesJboyer@aol.com Subject: Re: Pietenpol-List: Re: Useful Weight --> Pietenpol-List message posted by: JamesJboyer@aol.com Hello Piet List. I'm trying to find the address and name of the person who owns the Piet in Lancaster, CA. I will be in that area for the next three days and if possible would like to see his airplane. Appreciate any replys. Thanks, Jim Reserved # NX499JB ________________________________ Message 10 ____________________________________ Time: 04:46:46 PM PST US From: "Jim Markle" Subject: Re: Pietenpol-List: Re: Useful Weight --> Pietenpol-List message posted by: "Jim Markle" Might be: Scott at pietman@qnet.com , he is a member of EAA 49 in Lancaster California and built one with his father. You can see a shot of his plane at http://www.eaa49.av.org/index.htm . Jim in Plano Reserved #NX25JM > --> Pietenpol-List message posted by: JamesJboyer@aol.com > > Hello Piet List. > > I'm trying to find the address and name of the person who owns the Piet in > Lancaster, CA. I will be in that area for the next three days and if possible > would like to see his airplane. > > Appreciate any replys. Thanks, Jim > Reserved # NX499JB > > ________________________________ Message 11 ____________________________________ Time: 07:55:38 PM PST US From: "Richard Navratil" Subject: Pietenpol-List: prop HTML_MESSAGE --> Pietenpol-List message posted by: "Richard Navratil" I was doing my engine test the other day and in the full power run I was able to get 1900 rpm static run with an A-65 and a 72x42 prop. I expected a bit higher rpm. Is this close to what others have gotten? Also reading thru materials from EAA on inspections they talk about a prop log. I went out to the local FBO to buy one and the owner said he doesn't keep them for J-3's and such, he just makes entries in the airframe log. Does the DAR want to see a Prop log? Dick ________________________________ Message 12 ____________________________________ Time: 07:59:40 PM PST US From: "DOUGLAS BLACKBURN" Subject: Re: Pietenpol-List: Re: Useful Weight Seal-Send-Time: Tue, 16 Sep 2003 19:58:24 -0700 HTML_MESSAGE, MISSING_OUTLOOK_NAME, REFERENCES --> Pietenpol-List message posted by: "DOUGLAS BLACKBURN" His name is Scott out of EAA chapter 49. Here is the link that shows some pictures of his plane. I met him at Flabapb a couple of years ago and was able to see his plane. Tube fuse. SWEET!!!! He's a nice guy. Here is the email address and the link to their club page. Look under "Members planes/projects. He is about five down on the list. NOw his plane is dark green with a hint of yellow highlights. There is also a gal at their chapter that flies a Piet, but I have never met her. I'll send you a picture of them together at a Corona Piet fly-in a few years back to your home email address. Scott pietman@qnet.com , and here is the club link, http://www.eaa49.av.org/index.htm . Have fun. Doug Blackburn Doug/Elizabeth Blackburn Yucaipa California www.inlandsloperebels.com W.W. conversion manual, #3202 www.flycorvair.com ----- Original Message ----- From: JamesJboyer@aol.com To: pietenpol-list@matronics.com Sent: Tuesday, September 16, 2003 3:43 PM Subject: Re: Pietenpol-List: Re: Useful Weight --> Pietenpol-List message posted by: JamesJboyer@aol.com Hello Piet List. I'm trying to find the address and name of the person who owns the Piet in Lancaster, CA. I will be in that area for the next three days and if possible would like to see his airplane. Appreciate any replys. Thanks, Jim Reserved # NX499JB ________________________________ Message 13 ____________________________________ Time: 09:16:29 PM PST US From: "Christian Bobka" Subject: Re: Pietenpol-List: prop --> Pietenpol-List message posted by: "Christian Bobka" Dick, The taylorcraft with an A-65 is min 2070 and max 2250 rpm for static runup. That is with a 70-72 " diameter prop of appropriate pitch to give the static range, usually 42-44". Chris bobka ----- Original Message ----- From: "Richard Navratil" Subject: Pietenpol-List: prop > --> Pietenpol-List message posted by: "Richard Navratil" > > I was doing my engine test the other day and in the full power run I was able to get 1900 rpm static run with an A-65 and a 72x42 prop. I expected a bit higher rpm. Is this close to what others have gotten? > Also reading thru materials from EAA on inspections they talk about a prop log. I went out to the local FBO to buy one and the owner said he doesn't keep them for J-3's and such, he just makes entries in the airframe log. Does the DAR want to see a Prop log? > Dick > > ________________________________ Message 14 ____________________________________ Time: 09:58:24 PM PST US From: JamesJboyer@aol.com Subject: Re: Pietenpol-List: Re: Useful Weight MIME_LONG_LINE_QP@matronics.com, NO_REAL_NAME@matronics.com --> Pietenpol-List message posted by: JamesJboyer@aol.com In a message dated 9/16/2003 8:00:14 PM Pacific Standard Time, twinboom@msn.com writes: > http://www.eaa49.av.org/index.htm Hi Doug, Thank you very much for the pictures and email for Scott. If you are ever up in Santa Rosa, CA give me a call and I can show my wing ribs, fuselage, and tail surfaces all done. How exciting, I can just see you! Thanks again Doug. Jim; phone is 707-544-5594 ________________________________ Message 15 ____________________________________ Time: 10:01:51 PM PST US From: JamesJboyer@aol.com Subject: Re: Pietenpol-List: Re: Useful Weight NO_REAL_NAME@matronics.com --> Pietenpol-List message posted by: JamesJboyer@aol.com HI Jim, Thanks for the information on Scott and his Piet. If you are ever in Santa Rosa, CA give me a call or email and I will be glad to show you all the parts I have done. Am working on steel parts now and have 94 cut out and some actually almost done in addition to having all tail surfaces, fuselage, and wing ribs done. Cheers, Jim (also name I go by) 707-544-5594