Original Posted By: "Sayre, William G"
While goofing off in Ed Snyder's Piet one day Andrew King saidthat he un-latched the flop and it didn't move. He could move itaround at will. It didn't lift up like you might expect. The real keyhere is the turbulence which may or may not be generated by theshape of that cut out. (over the tail, that is.) Joe Leonard has fiddled with styrofoam in and out of his Grega cut out and hisobservation was not so much with lift as it was with turbulence.Mike C. I dunno. Have to experiment.________________________________________________________________________________
Pietenpol-List: Cut-out/Lift
Pietenpol-List: Cut-out/Lift
Original Posted By: Ian Holland
Joe Leonard has fiddled with styrofoam in and out of his Grega cut outand hisobservation was not so much with lift as it was with turbulence.Mike C. I dunno. Have to experiment.---------I think you'll find a difference between the Clark-Y airfoil that Gregauses and the Eiffle-36 (kinda) that Pietenpol used.Bill________________________________________________________________________________
Joe Leonard has fiddled with styrofoam in and out of his Grega cut outand hisobservation was not so much with lift as it was with turbulence.Mike C. I dunno. Have to experiment.---------I think you'll find a difference between the Clark-Y airfoil that Gregauses and the Eiffle-36 (kinda) that Pietenpol used.Bill________________________________________________________________________________
Pietenpol-List: Re: Cut-out/Lift
Original Posted By: jimsury(at)fbtc.net (Jim Sury)
>>Joe Leonard has fiddled with styrofoam in and out of his Grega cut out>and his>observation was not so much with lift as it was with turbulence.>Mike C. I dunno. Have to experiment.>--------->I think you'll find a difference between the Clark-Y airfoil that Grega>uses and the Eiffle-36 (kinda) that Pietenpol used.>>Bill>>I'm building a Grega GN-1 and as far as I can tell the airfoil is the sameas the Piet. airfoil. I believe the Clark-Y has a flat bottom. My plansshowed the airfoil to have a concaved lower surface just as the Pietenpols.Jim________________________________________________________________________________
>>Joe Leonard has fiddled with styrofoam in and out of his Grega cut out>and his>observation was not so much with lift as it was with turbulence.>Mike C. I dunno. Have to experiment.>--------->I think you'll find a difference between the Clark-Y airfoil that Grega>uses and the Eiffle-36 (kinda) that Pietenpol used.>>Bill>>I'm building a Grega GN-1 and as far as I can tell the airfoil is the sameas the Piet. airfoil. I believe the Clark-Y has a flat bottom. My plansshowed the airfoil to have a concaved lower surface just as the Pietenpols.Jim________________________________________________________________________________
Pietenpol-List: Re: Cut-out/Lift
Original Posted By: "Alan A. Laudani"
Right on, Michael! I flew mine for about two years with a cut-out centersection and then modified it to incorporate the "flop". As a result, theclimb improved noticeably and the airflow over the tail smoothed out, re-lieving a bit of tailheaviness in flight.I use simple cupboard clips to hold it in position, one per side on thelower surface. These primarily keep the flop from "flopping" down while on the ground; in flight it will trail about even with the wing TEwithout the clips in place.Lifting the flop slightly in flight for some reason causes the nose topitch down (possibly because of disturbed airflow over the horizontalstab). Despite blocking the upward view from the rear pit, I wouldrecommend the flop be used on these airplanes--and it also provides shade from the sun in true "parasol" fashion.Cheers to all, GrahamOn Tue, 14 Oct 1997, Michael D Cuy wrote:> While goofing off in Ed Snyder's Piet one day Andrew King said> that he un-latched the flop and it didn't move. He could move it> around at will. It didn't lift up like you might expect. The real key> here is the turbulence which may or may not be generated by the> shape of that cut out. (over the tail, that is.) Joe Leonard has > fiddled with styrofoam in and out of his Grega cut out and his> observation was not so much with lift as it was with turbulence.> Mike C. I dunno. Have to experiment.> ________________________________________________________________________________
Right on, Michael! I flew mine for about two years with a cut-out centersection and then modified it to incorporate the "flop". As a result, theclimb improved noticeably and the airflow over the tail smoothed out, re-lieving a bit of tailheaviness in flight.I use simple cupboard clips to hold it in position, one per side on thelower surface. These primarily keep the flop from "flopping" down while on the ground; in flight it will trail about even with the wing TEwithout the clips in place.Lifting the flop slightly in flight for some reason causes the nose topitch down (possibly because of disturbed airflow over the horizontalstab). Despite blocking the upward view from the rear pit, I wouldrecommend the flop be used on these airplanes--and it also provides shade from the sun in true "parasol" fashion.Cheers to all, GrahamOn Tue, 14 Oct 1997, Michael D Cuy wrote:> While goofing off in Ed Snyder's Piet one day Andrew King said> that he un-latched the flop and it didn't move. He could move it> around at will. It didn't lift up like you might expect. The real key> here is the turbulence which may or may not be generated by the> shape of that cut out. (over the tail, that is.) Joe Leonard has > fiddled with styrofoam in and out of his Grega cut out and his> observation was not so much with lift as it was with turbulence.> Mike C. I dunno. Have to experiment.> ________________________________________________________________________________
Pietenpol-List: Re: Cut-out/Lift
Original Posted By:> Michael D Cuy