Original Posted By: TomTravis(at)aol.com
Subject: Pietenpol-List: Beauty in Simplicity and Slow SpeedIn a message dated 8/2/2006 1:26:47 PM Central Standard Time, Isablcorky(at)aol.com writes:Pieters,Here I am butting in on your conversations again. I am pleased to see some discussions begin on the subject of Piet technics. Granted, the Piet is a welldesigned machine and has weathered the years and hardly anyone has received harm. But can it be improved without changing it's basic designs?After completing and flying 41CC I felt that it's flying characterics could be greatly improved, especially the float after round out. Many said it was because of high drag that caused the falling brick sensation. The Cub and 7AC both have a nice float, are heavier and posses abundant drag AND with 65 HP. AsI was building 311CC I strongly considered the Cub airfoil as well as the 7AC and the Clark Y. I feel now they are superior to the BHP French 10.If I were to build again it would definitely be with a different airfoil. That Piet airfoil is in my opinion the weakest link of the Piet chain design.Two-bits worth on this beautiful Southern afternoon.I'll be waiting your bombardments with my old steel helmet.CMCOK Corky,Put on that ol' steel helmet, 'cause I'm coming after ya !! he he !!If you change the airfoil of the Pietenpol, you Have changed it's basic design, because it is actually one of it's strongest links. Here's why: The airfoil is like flying with a notch of flaps, always in - high drag and lots of Lift. All this lift allows you to take off and land at very slow speeds, which explains why it has such a good safety record - injuries will more often if there is an increase if the touchdown speed has to be increased. This airfoil is also why Bernard was able to design an airplane with the power output of a Model A engine. If you float after roundout, you will certainly land longer than if you didn't float. Untill you really get used to the landing characteristics of thePiet airfoil, you should leave a little bit of power in, and land a little longer. It takes dozens of landings, but after you get used to it, pull powerto idle on final approach, roundout and flair inches above the ground, and seejust how short the roll out can be. Those other airfoils you mentioned are designed into those particular airframes, and are most certainly better than the Piet airfoil in that particularapplication. The Pietenpol Does NOT have balanced control surfaces, and if the top speed is increased with a lower drag airfoil, then you increase the risk of Control Surface Flutter. If flutter occurs, it will only take a matter of secondsbefore the subject control surface will have complete, and catastrophic failure. This is the reason you should NEVER take the Pietenpol past the designVne of 90 mph. The Pietenpol airfoil has an aft C. of G. limit which is further aft on the airfoil than on almost any other airfoil, because of it's negative pitchingmoment, and if the airfoil is changed to something else, then you MUST use C.of G. limits according to the airfoil used - which will move the aft limit forward, and this will only aggravate the already aft C G condition that most Pietenpols have. There ya have it, Corky...my two-bit opinion :)Chuck G.NX770CG________________________________________________________________________________
Pietenpol-List: Beauty in Simplicity and Slow Speed
RE: Pietenpol-List: Beauty in Simplicity and Slow Speed
Original Posted By: Rcaprd(at)aol.com
Subject: RE: Pietenpol-List: Beauty in Simplicity and Slow SpeedGood post, ChuckJack Still sweating in Raleigh-----Original Message-----[mailto:owner-pietenpol-list-server(at)matronics.com] On Behalf OfRcaprd(at)aol.comSent: Thursday, August 03, 2006 9:34 PMIn a message dated 8/2/2006 1:26:47 PM Central Standard Time,Isablcorky(at)aol.com writes:Pieters, Here I am butting in on your conversations again. I am pleasedto see some discussions begin on the subject of Piet technics. Granted,the Piet is a well designed machine and has weathered the years andhardly anyone has received harm. But can it be improved without changingit's basic designs?After completing and flying 41CC I felt that it's flyingcharacterics could be greatly improved, especially the float after roundout. Many said it was because of high drag that caused the falling bricksensation. The Cub and 7AC both have a nice float, are heavier andposses abundant drag AND with 65 HP. As I was building 311CC I stronglyconsidered the Cub airfoil as well as the 7AC and the Clark Y. I feelnow they are superior to the BHP French 10.If I were to build again it would definitely be with a differentairfoil. That Piet airfoil is in my opinion the weakest link of the Pietchain design.Two-bits worth on this beautiful Southern afternoon.I'll be waiting your bombardments with my old steel helmet. CMCOK Corky,Put on that ol' steel helmet, 'cause I'm coming after ya !! he he !!If you change the airfoil of the Pietenpol, you Have changed it's basicdesign, because it is actually one of it's strongest links. Here's why: The airfoil is like flying with a notch of flaps, always in - highdrag and lots of Lift. All this lift allows you to take off and land atvery slow speeds, which explains why it has such a good safety record -injuries will more often if there is an increase if the touchdown speedhas to be increased. This airfoil is also why Bernard was able to design an airplane withthe power output of a Model A engine. If you float after roundout, you will certainly land longer than ifyou didn't float. Untill you really get used to the landingcharacteristics of the Piet airfoil, you should leave a little bit ofpower in, and land a little longer. It takes dozens of landings, butafter you get used to it, pull power to idle on final approach, roundoutand flair inches above the ground, and see just how short the roll outcan be. Those other airfoils you mentioned are designed into thoseparticular airframes, and are most certainly better than the Pietairfoil in that particular application. The Pietenpol Does NOT have balanced control surfaces, and if thetop speed is increased with a lower drag airfoil, then you increase therisk of Control Surface Flutter. If flutter occurs, it will only take amatter of seconds before the subject control surface will have complete,and catastrophic failure. This is the reason you should NEVER take thePietenpol past the design Vne of 90 mph. The Pietenpol airfoil has an aft C. of G. limit which is further afton the airfoil than on almost any other airfoil, because of it'snegative pitching moment, and if the airfoil is changed to somethingelse, then you MUST use C.of G. limits according to the airfoil used -which will move the aft limit forward, and this will only aggravate thealready aft C G condition that most Pietenpols have. There ya have it, Corky...my two-bit opinion :)Chuck G.NX770CG_________________________________________________This message is for the designated recipient only and may contain privileged, proprietary, or otherwise private information. If you have received it in error, please notify the sender immediately and delete the original. Any other use of the email by you is prohibited.Dansk - Deutsch - Espanol - Francais - Italiano - Japanese - Nederlands - N________________________________________________________________________________
Subject: RE: Pietenpol-List: Beauty in Simplicity and Slow SpeedGood post, ChuckJack Still sweating in Raleigh-----Original Message-----[mailto:owner-pietenpol-list-server(at)matronics.com] On Behalf OfRcaprd(at)aol.comSent: Thursday, August 03, 2006 9:34 PMIn a message dated 8/2/2006 1:26:47 PM Central Standard Time,Isablcorky(at)aol.com writes:Pieters, Here I am butting in on your conversations again. I am pleasedto see some discussions begin on the subject of Piet technics. Granted,the Piet is a well designed machine and has weathered the years andhardly anyone has received harm. But can it be improved without changingit's basic designs?After completing and flying 41CC I felt that it's flyingcharacterics could be greatly improved, especially the float after roundout. Many said it was because of high drag that caused the falling bricksensation. The Cub and 7AC both have a nice float, are heavier andposses abundant drag AND with 65 HP. As I was building 311CC I stronglyconsidered the Cub airfoil as well as the 7AC and the Clark Y. I feelnow they are superior to the BHP French 10.If I were to build again it would definitely be with a differentairfoil. That Piet airfoil is in my opinion the weakest link of the Pietchain design.Two-bits worth on this beautiful Southern afternoon.I'll be waiting your bombardments with my old steel helmet. CMCOK Corky,Put on that ol' steel helmet, 'cause I'm coming after ya !! he he !!If you change the airfoil of the Pietenpol, you Have changed it's basicdesign, because it is actually one of it's strongest links. Here's why: The airfoil is like flying with a notch of flaps, always in - highdrag and lots of Lift. All this lift allows you to take off and land atvery slow speeds, which explains why it has such a good safety record -injuries will more often if there is an increase if the touchdown speedhas to be increased. This airfoil is also why Bernard was able to design an airplane withthe power output of a Model A engine. If you float after roundout, you will certainly land longer than ifyou didn't float. Untill you really get used to the landingcharacteristics of the Piet airfoil, you should leave a little bit ofpower in, and land a little longer. It takes dozens of landings, butafter you get used to it, pull power to idle on final approach, roundoutand flair inches above the ground, and see just how short the roll outcan be. Those other airfoils you mentioned are designed into thoseparticular airframes, and are most certainly better than the Pietairfoil in that particular application. The Pietenpol Does NOT have balanced control surfaces, and if thetop speed is increased with a lower drag airfoil, then you increase therisk of Control Surface Flutter. If flutter occurs, it will only take amatter of seconds before the subject control surface will have complete,and catastrophic failure. This is the reason you should NEVER take thePietenpol past the design Vne of 90 mph. The Pietenpol airfoil has an aft C. of G. limit which is further afton the airfoil than on almost any other airfoil, because of it'snegative pitching moment, and if the airfoil is changed to somethingelse, then you MUST use C.of G. limits according to the airfoil used -which will move the aft limit forward, and this will only aggravate thealready aft C G condition that most Pietenpols have. There ya have it, Corky...my two-bit opinion :)Chuck G.NX770CG_________________________________________________This message is for the designated recipient only and may contain privileged, proprietary, or otherwise private information. If you have received it in error, please notify the sender immediately and delete the original. Any other use of the email by you is prohibited.Dansk - Deutsch - Espanol - Francais - Italiano - Japanese - Nederlands - N________________________________________________________________________________