---------------------------------------------------------- Pietenpol-List Digest Archive --- Total Messages Posted Tue 09/05/17: 4 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 09:16 AM - Re: Sky Scout Plans (DonkDoug) 2. 10:20 AM - Re: Sky Scout Plans (DonkDoug) 3. 08:31 PM - Re: Re: Sky Scout Plans ((null) raykrause) 4. 09:41 PM - Re: Sky Scout Plans (DonkDoug) ________________________________ Message 1 _____________________________________ Time: 09:16:53 AM PST US Subject: Pietenpol-List: Re: Sky Scout Plans From: "DonkDoug" Ray, I was looking at your weight and balance info and I have a question. Did you estimate the pilot moment arm location or did you determine the actual location by weighing the airplane while sitting in it? The reason I ask is because when I looked at the weight and balance sheet Bernard Pietenpol published for his 1966 Air Camper you can calculate that he used a location approximately 16" forward of the point where the pilot seat back and bottom intersect. In that the seats for the Sky Scout and Air Camper have about the same geometry if you were to use the same distance it would put your pilot moment arm at approximately 36" from your datum, the leading edge of the wing. That, of course, would make a significant, favorable difference in your CG location. Doug Read this topic online here: http://forums.matronics.com/viewtopic.php?p=472512#472512 ________________________________ Message 2 _____________________________________ Time: 10:20:56 AM PST US Subject: Pietenpol-List: Re: Sky Scout Plans From: "DonkDoug" Ray, After re-reading my last post I need to correct some imprecise wording on my part. From the 1966 Piet W/B info I calculated the pilot moment arm location was about 16" forward of the seat intersection point. Doug Read this topic online here: http://forums.matronics.com/viewtopic.php?p=472517#472517 ________________________________ Message 3 _____________________________________ Time: 08:31:16 PM PST US From: "(null) raykrause" Subject: Re: Pietenpol-List: Re: Sky Scout Plans Doug, For that number, I used a more recent publication of W/B calculations in one of the recent Brodhead newsletters. It seems to have come from the old CAA. It shows three graphs based on seat back angle and pilot weight that gives inches ahead of the seatback/seat bench angle for the CG of the pilot. My seat back is 15 degrees, I'm 200 lbs, it offered 7.5" ahead of the angle for the pilot CG. That's what I used. Still, the best fix would be the fuselage front 2" longer, or a longer motor mount. That would really solve the problem. Remember that when you build. I would go with the longer mount so the motor would be further ahead of the gear but still the same in relation to the LE. I would also shorten the front leg of the gear so the wheel weigh point would be closer to the LE. Bernard, in his last plans for the Covair engined AirCamper, said the gear should be .5" behind the LE. If you use 20-21" wheels as I am, the fuselage "slope" is really steep, but I can't remember the angle (AOA) right now but there is a lot of prop clearance. I will get the angle tomorrow. Smaller, lighter wheels would help my CG. RAY Sent from my iPad > On Sep 5, 2017, at 9:16 AM, DonkDoug wrote: > > > Ray, > > I was looking at your weight and balance info and I have a question. Did you estimate the pilot moment arm location or did you determine the actual location by weighing the airplane while sitting in it? The reason I ask is because when I looked at the weight and balance sheet Bernard Pietenpol published for his 1966 Air Camper you can calculate that he used a location approximately 16" forward of the point where the pilot seat back and bottom intersect. In that the seats for the Sky Scout and Air Camper have about the same geometry if you were to use the same distance it would put your pilot moment arm at approximately 36" from your datum, the leading edge of the wing. That, of course, would make a significant, favorable difference in your CG location. > > Doug > > > > > Read this topic online here: > > http://forums.matronics.com/viewtopic.php?p=472512#472512 > > > > > > > > > ________________________________ Message 4 _____________________________________ Time: 09:41:34 PM PST US Subject: Pietenpol-List: Re: Sky Scout Plans From: "DonkDoug" Ray, I think that CAA material you referenced got the pilot CG about right. When you mentioned the Brodhead newsletters I dug out William's article on Piet W/B for Continental powered ships. He had calculated pilot CG location for each of the airplanes he weighed. The location is very close to what you had calculated. The mean of the values was about 7" forward of the seat bottom/seat back intersection. Now I need to figure out how I fouled up the calculation from Mr. Pietenpol's 1966 W/B sheet. I think my assumption as the where there is 8 gallons of fuel stored was incorrect. Doug Read this topic online here: http://forums.matronics.com/viewtopic.php?p=472542#472542 ------------------------------------------------------------------------------------- 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.