Pietenpol-List: stall speeds

matronics · Post by **matronics** » Sun Nov 16, 2008 7:57 pm

Original Posted By: "Skip Gadd"
Howdy=2C Pietenpolers-In preparation for experimenting with vortex generators on the wings and horizontal stabilizer of 41CC(close your ears=2C purists!)=2C I went up this afternoon to run a stall series to get a rough idea of whatthe stall speeds are for my airplane. It was a cool afternoon with a light breeze=2C just me aboard andhalf a tank of fuel. That's as scientific as I'm going to get up to this point. I took the airplane up toabout 2500 ft. (climbed like a rocket in the cool air) and did stalls power-off and power-on. The pitotgets a little crazy during power-on stalls due to the extreme angle and the propwash=2C so the airspeedneedle jumps around quite a bit and I'm sure the readings aren't very accurate=2C but I'll get relativenumbers "before and after" anyway.Power-off stalls happen at 37-38 MPH and power-on happen at about 32-34 indicated. The airplanehas to be stalled briskly or it will just go nose-high and mush without much of a break at the stall.The nose will then bob up and down in and out of stall. Bringing the nose up crisply and quickly willbring it to a more noticeable stall. Rudders are required to keep the nose straight.Oscar ZunigaAir Camper NX41CCSan Antonio=2C TXmailto: taildrags(at)hotmail.comwebsite at http://www.flysquirrel.net________________________________________________________________________________

matronics · Post by **matronics** » Sun Nov 16, 2008 8:21 pm

Original Posted By: Oscar Zuniga
Oscar,P. F. Beck has vortex generators on his Corvair Piet. He told me they reduced thestall enough that he thought they were worthwhile, I don't remember the numbers.Skip----- Original Message -----

matronics · Post by **matronics** » Sun Nov 16, 2008 8:25 pm

Original Posted By: Darrel Jones

matronics · Post by **matronics** » Sun Nov 16, 2008 9:17 pm

Original Posted By: Michael Perez
Michael,The ribs on NX18235 are attached to the spar with T-88, not nails. I think this far more common than nailing the ribs to the spars.Greg Cardinal ----- Original Message -----

matronics · Post by **matronics** » Mon Nov 17, 2008 12:45 am

Original Posted By: Oscar Zuniga
Try this;http://www.kcdawnpatrol.org/machine-gun.htmClif> I am also looking for the propane machine gun plans. I didn't want to > re-invent the wheel trying to come up with one for my airplane. Please > let me know what you find.> > Thanks,> Darrel Jones,________________________________________________________________________________

matronics · Post by **matronics** » Tue Apr 14, 2009 2:28 pm

Original Posted By: "Jack Phillips"
Hi,Looked thru the archives and noticed that vortex generators have been mentioned,and a number of people said they were going to experiment with them, but I couldn'tfind where anyone had actually tried them out on a piet. Seems like about35 mph is accepted as the average stall speed. Anyone have before/after numbers?JimRead this topic online here:http://forums.matronics.com/viewtopic.p ... __________

matronics · Post by **matronics** » Tue Apr 14, 2009 2:43 pm

Original Posted By: Jeff Boatright

matronics · Post by **matronics** » Tue Apr 14, 2009 2:45 pm

Original Posted By: owner-pietenpol-list-server(at)matronics.com
Why would you want to go slower than 35?Jack PhillipsNX899JP-----Original Message-----

matronics · Post by **matronics** » Tue Apr 14, 2009 3:05 pm

Original Posted By: gliderx5(at)comcast.net
I would assume the higher stall is due to having a cleaner than average plane,or maybe the 35 mph number isn't accurate (unless it was gps I would wonder.)Was curious as the safety of the plane would seem to increase a bit as the landingspeed/stall speed decreased. (Since the force is mass x velocity squared.)In the midwest it might not actually increase safety as there are other ways toget in trouble. I remember flying backward in a piper cub solo before and havingto take and rush a champ in to a hangar before a squall line hit, as it wouldpick the plane up and dump it over. In kansas/missouri we often have 25 milean hour winds and they typically are not steady, but gusty, so you could falloff one if your going to slow.I was speculating about my plane though, it should weigh about 750 lbs, has 125hp and two high lift wings (aerial biplane version of piet). It for sure is notgoing to be a fast plane, but it could be S.T.O.L. and that was what made mewonder if anyone had done VG's on a pietenpol yet, and what their experienceis.Doubt I would do it only because the nice vintage biplane look would be off a bitwith a 100 or so VG's across the wings.JimRead this topic online here:http://forums.matronics.com/viewtopic.p ... ______Date: Tue, 14 Apr 2009 22:10:22 +0000 (UTC)

matronics · Post by **matronics** » Tue Apr 14, 2009 6:32 pm

Original Posted By: Jeff Boatright
Subject: RE: Pietenpol-List: Re: stall speedsI agree with Jack, why would you want to stall slower than the Piet normally stallsat ? Mine power-off stalls at 29 mph. ________________________________________________________________________________Date: Tue, 14 Apr 2009 19:44:01 -0400

matronics · Post by **matronics** » Tue Apr 14, 2009 9:28 pm

Original Posted By: Jeff Boatright

matronics · Post by **matronics** » Fri Apr 28, 2017 9:33 pm

Original Posted By: gliderx5(at)comcast.net
________________________________________________________________________________Date: Tue, 14 Apr 2009 22:18:11 +0000 (UTC)

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