Brodhead Pietenpol Association

Original Posted By: Mike Cunningham
>Dear Sirs,>Can anyone tell me what wing wash out should be - or could be - on a GN-1>with no dihedral? I'm having a time finding anything on this. I'd>appreciate your help.>Larry PasleyLarry- the wise older gentlemen where I fly (who rebuild and rig Cubs, Champs,etc.) suggested I put 3/8" washout about 3 ribs in from the wingtip. I guessit keeps the ailerons working longer as you begin to stall.Mike C. Dear Sirs,Can anyone tell me what wing wash out should be - or could be - on aGN-1with no dihedral? I'm having a time finding anything on this.I'dappreciate your help.Larry PasleyLarry- the wise older gentlemen where I fly (who rebuild and rigCubs, Champs,etc.) suggested I put 3/8 washout about 3 ribs in from thewingtip. I guessit keeps the ailerons working longer as you begin to stall.Mike C. ________________________________________________________________________________

Original Posted By: Nahuel Garavaglia
At an Oshkosh forum a few years ago, Vi Kapler advised a 3/8" washoutfor better stall warning. He went on to that this was his opinion andthat Bernie Pietenpol never used any washout.Dean Daytondayton(at)netwalk.comMichael Cuy wrote:> >Dear Sirs,> >Can anyone tell me what wing wash out should be - or could be - on a> GN-1> >with no dihedral? I'm having a time finding anything on this. I'd> >appreciate your help.> >Larry Pasley>> Larry- the wise older gentlemen where I fly (who rebuild and rig> Cubs, Champs,> etc.) suggested I put 3/8" washout about 3 ribs in from the wingtip.> I guess> it keeps the ailerons working longer as you begin to stall.> Mike C.At an Oshkosh forum a few years ago, Vi Kapler advised a 3/8" washout forbetter stall warning. He went on to that this was his opinion andthat Bernie Pietenpol never used any washout.Dean Daytondayton(at)netwalk.comMichael Cuy wrote:>Dear Sirs,>Can anyone tell me what wing wash out should be - or could be - ona GN-1>with no dihedral? I'm having a time finding anything on this. I'd>appreciate your help.>Larry PasleyLarry- the wise older gentlemen where I fly (who rebuild andrig Cubs, Champs,etc.) suggested I put 3/8" washout about 3 ribs in from the wingtip.I guessit keeps the ailerons working longer as you begin to stall.Mike C.________________________________________________________________________________

Original Posted By: Phil Peck
Thanks to you and Dean Dalton for the information. It's appreciated. NowI'll try to get it set up right.Larry> >Dear Sirs,> >Can anyone tell me what wing wash out should be - or could be - on a GN-1> >with no dihedral? I'm having a time finding anything on this. I'd> >appreciate your help.> >Larry Pasley> > Larry- the wise older gentlemen where I fly (who rebuild and rig Cubs,> Champs,> etc.) suggested I put 3/8" washout about 3 ribs in from the wingtip. Iguess> it keeps the ailerons working longer as you begin to stall.> Mike C. ________________________________________________________________________________

Original Posted By: bowdler(at)juno.com
Subject: Pietenpol-List: Re: washout>I think you have mistaken the "deep stall" phenomena. The deep stalls>are usually associated with T or high mounted vertical>stabalizers/elevators. The normal down pitch after a stall is due to the>fact that the elevator/stab is still capable of providing some>stabalizing force even after the wing has stopped producing lift. If, for>some reason, the stabalizer becomes ineffective, the plane will continue>to descend in a nose high, full stall attitude. This can occur on a T-tail>plane or any plane where the tail is 5-15 degrees above the chordline of>the wing. The turbulent air from the stalled wing will "mask " the>elevator and stabalizer making it ineffective. At this point, only>vigerous application of power, elevators and flaps can help break from the>stall.>>You can see the result of this on an F-4 Phantom. Even though it's not a>T-tail, the delta wing and engine outlet put the root of the stabilators>in the deep stall position. You will note that the stabilators have a very>prnounced down angle to get them out of the wing shadow.>>Actually, the prototype Canadair 601 Challenger was lost in just this>manner. The test plane had been equipped with an emergency drouge chute>attached to the last bulkhead inside the tailcone. Sure enough, a deep>stall developed and the test pilot fired the chute which pulled it out of>the stall. Unfortunately, the explosive bolts used to attach the chute to>the plane malfunctioned and the chute could not be cut. All of the crew>bailed out except the pilot. He almost recovered the plane but ran out of>height and impacted the desert floor. It was speculated that with another>300-500', he may have recovered enough to land it. The pilot was killed>instantly.>>Ken>>On Fri, 7 May 1999, David Scott wrote:>>> 2) Limited elevator down force capability will prevent>>>>>> 3) Dihedral angle can help, but not always true.>>________________________________________________________________________________

Original Posted By: Ian Holland
Subject: Re: washout A friend has an Ercoupe that he likes quite a lot. Partly because he can open the canopy while cruising. I never asked him what it's like to land in a cross wind with no aileron controls. So, what's it like to land in a cross wind with no aileron controls??? It's also a really neat looking plane. I think he bought his for only about $12,000 and it looks like a lot of plane for the money. I think that I like it also because it was built the same year I was, 1946. I think you reversed one thing below. Airfoils must be more effective at the tip, not less to prevent stall spins. Plan form of the wing certainly affects stall characteristics - the elipitical is referred to as the "perfect" plan form, in that it stalls evenly from tip to root. I don't know if that's perfect or not. Unless I get into aerobatics (not likely with a Piet) I think I would greatly prefer a plane that stalls at the roots first and the tips last. I think that swept back wings also tip stall earlier. I don't remember why??? I find really good explanations of general aerodynamics in books that are sold for the model aircraft market. They seem to cover a lot more design detail without becoming an outright engineering treatise that I seem to find so hard to digest in full sized aircraft design texts. Andy Lennon is the author of one that I've gotten a whole lot of understanding from. I can't remember the name, but it should be easy to find by author. His book is the one that I learned about the NASA wing design from that I mentioned. I have another book at home that is pretty good that is also titled as a model aircraft book, The main difference seems to be that Reynold's Numbers are a lot more important when dealing with small aircraft. Also, if you make a mistake with a model and the design is unstable, you always walk away from the crash. I'll try to remember to send the author and title later. Mike Bell (NoPietYet) Columbia, SC David Scott on 05/07/99 10:42:17 AM Please respond to Pietenpol Discussion To: Pietenpol Discussion cc: Subject: Re: washout I am a little confused on this one. I have flown quite a few hours in several Ercoupes which are highly spin resistant. The basics of spin resistance are: 1) Wing tips are always LAST to stall. This insures etc..) 2) Limited elevator down force capability will prevent 3) Dihedral angle can help, but not always true. I would be interested in reading the sources, if you happen to know where to find them. I believe the above will most likely be the reason why you will ALWAYS see wings with methods implemented for the tips to stall last. Remember - No plane will stall-spin unless a stall occurs first! (Only for a CFI license does one ever have to show certificate...) David Scott Washington, IL Mike Bell wrote: > I thought that washout was to keep your tips from stalling before > your wing root and therefore provide a modicum of spin protection > and stability at the start of a stall. If you want an aerobatic > Peietenpol (oxymoron) then you would bend your tips up a little > instead and promote tip stalling. NASA designed a wing with a > more aggressive airfoil at the tips that was "spin proof". I > wonder why I've never seen it on a production or experimental > aircraft? > > I haven't received my plans yet. How do you set washout on the > Piet? Is it built in or do you tighten and loosen support/drag > cables? > > Mike Bell (NoPietYet) > Columbia, SC > > lpasley on 05/06/99 10:41:01 PM > > Please respond to Pietenpol Discussion > > To: Pietenpol Discussion > cc: > Subject: Re: washout > > Thanks to you and Dean Dalton for the information. It's > appreciated. Now > I'll try to get it set up right. > Larry > > ---------- > > >Dear Sirs, > > >Can anyone tell me what wing wash out should be - or could be > - on a GN-1 > > >with no dihedral? I'm having a time finding anything on this. > I'd > > >appreciate your help. > > >Larry Pasley > > > > Larry- the wise older gentlemen where I fly (who rebuild and > rig Cubs, > > Champs, > > etc.) suggested I put 3/8" washout about 3 ribs in from the > wingtip. I > guess > > it keeps the ailerons working longer as you begin to stall. > > Mike C. --________________________________________________________________________________

Original Posted By: Joe Krzes
I thought that washout was to keep your tips from stalling beforeyour wing root and therefore provide a modicum of spin protectionand stability at the start of a stall. If you want an aerobaticPeietenpol (oxymoron) then you would bend your tips up a littleinstead and promote tip stalling. NASA designed a wing with amore aggressive airfoil at the tips that was "spin proof". Iwonder why I've never seen it on a production or experimentalaircraft?I haven't received my plans yet. How do you set washout on thePiet? Is it built in or do you tighten and loosen support/dragcables?Mike Bell (NoPietYet)Columbia, SClpasley on 05/06/99 10:41:01 PMPlease respond to Pietenpol Discussion cc:Subject: Pietenpol-List: Re: washoutThanks to you and Dean Dalton for the information. It'sappreciated. NowI'll try to get it set up right.Larry> >Dear Sirs,> >Can anyone tell me what wing wash out should be - or could be- on a GN-1> >with no dihedral? I'm having a time finding anything on this.I'd> >appreciate your help.> >Larry Pasley>> Larry- the wise older gentlemen where I fly (who rebuild andrig Cubs,> Champs,> etc.) suggested I put 3/8" washout about 3 ribs in from thewingtip. Iguess> it keeps the ailerons working longer as you begin to stall.> Mike C.________________________________________________________________________________

Original Posted By: David Scott
Speaking of stalling, can anybody out there talk about the stall characteristics of the Pietenpol Aircamper? Mush? sudden break? buffet?, drops a wing?, etc? Anybody ever spin their piet either intentionally or accidentally? Standard recovery procedures work?Joe>From: Mike Bell >Reply-To: Pietenpol Discussion >To: Pietenpol Discussion >Subject: Re: washout>Date: Fri, 07 May 1999 08:52:06 -0400>>>I thought that washout was to keep your tips from stalling before>your wing root and therefore provide a modicum of spin protection>and stability at the start of a stall. If you want an aerobatic>Peietenpol (oxymoron) then you would bend your tips up a little>instead and promote tip stalling. NASA designed a wing with a>more aggressive airfoil at the tips that was "spin proof". I>wonder why I've never seen it on a production or experimental>aircraft?>>I haven't received my plans yet. How do you set washout on the>Piet? Is it built in or do you tighten and loosen support/drag>cables?>>Mike Bell (NoPietYet)>Columbia, SC>>>lpasley on 05/06/99 10:41:01 PM>>Please respond to Pietenpol Discussion >>To: Pietenpol Discussion >cc:>Subject: Re: washout>>>Thanks to you and Dean Dalton for the information. It's>appreciated. Now>I'll try to get it set up right.>Larry>>----------> > >Dear Sirs,> > >Can anyone tell me what wing wash out should be - or could be>- on a GN-1> > >with no dihedral? I'm having a time finding anything on this.>I'd> > >appreciate your help.> > >Larry Pasley> >> > Larry- the wise older gentlemen where I fly (who rebuild and>rig Cubs,> > Champs,> > etc.) suggested I put 3/8" washout about 3 ribs in from the>wingtip. I>guess> > it keeps the ailerons working longer as you begin to stall.> > Mike C.>>________________________________________________________________________________

Original Posted By: Wkoucky(at)aol.com
I am a little confused on this one. I have flown quite a fewhours in several Ercoupes which are highly spin resistant.The basics of spin resistance are: 1) Wing tips are always LAST to stall. This insures controllability with stall occuring. Because of the greater moment arm at the tips, should one wing tip be producing lift while the other is not, greater spin tendancy will be present. Whereas if it is the wing roots which are causing the differential lift, spin tendacy will be less. With the tips being last to stall, the control surfaces will be still be effective with the start of a stall. Methods for this are: 2) Limited elevator down force capability will prevent deep stall of the main wing. An Ercoupe is never really able to deep stall the main wing much past the middle root portion (non-accelerated stalls). It is really neat to demonstrate - yoke all the way back, decending about 600 fpm, but full control useage and about 50 mph on the airspeed. Get a CFI with you, and in a C152 and C172, you can get a 152 to marginally stay stable if you keep ball centered with the rudder, but a spin will happen quickly with a little more induced stall with power to push the tail down or just kick the rudder a little. A C172 is another animal. It has a little more elevator and well, you know the rest of the story. You can get more main wing stall with it and quicker results. 3) Dihedral angle can help, but not always true.I would be interested in reading the sources, if youhappen to know where to find them. I believe the abovewill most likely be the reason why you will ALWAYS seewings with methods implemented for the tips to stall last.Remember - No plane will stall-spin unless a stall occurs first! (Only for a CFI license does one ever have to show proof of spinning an airplane for a license certificate...)David ScottWashington, ILMike Bell wrote:> I thought that washout was to keep your tips from stalling before> your wing root and therefore provide a modicum of spin protection> and stability at the start of a stall. If you want an aerobatic> Peietenpol (oxymoron) then you would bend your tips up a little> instead and promote tip stalling. NASA designed a wing with a> more aggressive airfoil at the tips that was "spin proof". I> wonder why I've never seen it on a production or experimental> aircraft?>> I haven't received my plans yet. How do you set washout on the> Piet? Is it built in or do you tighten and loosen support/drag> cables?>> Mike Bell (NoPietYet)> Columbia, SC>> lpasley on 05/06/99 10:41:01 PM>> Please respond to Pietenpol Discussion >> To: Pietenpol Discussion > cc:> Subject: Re: washout>> Thanks to you and Dean Dalton for the information. It's> appreciated. Now> I'll try to get it set up right.> Larry>> ----------> > >Dear Sirs,> > >Can anyone tell me what wing wash out should be - or could be> - on a GN-1> > >with no dihedral? I'm having a time finding anything on this.> I'd> > >appreciate your help.> > >Larry Pasley> >> > Larry- the wise older gentlemen where I fly (who rebuild and> rig Cubs,> > Champs,> > etc.) suggested I put 3/8" washout about 3 ribs in from the> wingtip. I> guess> > it keeps the ailerons working longer as you begin to stall.> > Mike C.-----------1---------2---------3---------4---------5---------6---------7/-------------------- |~~_____/~~__ ||scott(at)haulpak.com | o' ~~|~~~ |I am a little confused on this one. I have flown quite a fewhours in several Ercoupes which are highly spin resistant.The basics of spin resistance are: 1) Wing tips are always LAST to stall.This insures controllabilitywith stall occuring. Because of the greater momentarm at the tips, should one wing tip be producinglift while the other is not, greater spin tendancywill be present. Whereas if it is the wing roots whichare causing the differential lift, spin tendacywill be less. With the tipsbeing last to stall, the control surfaces will be stillbe effective with the start of a stall. Methods for thisare:- angle of incidence less at the tips (washout)- airfoil effectivity less at the tips (size, area, etc..)- rectangular wing plan form (top view of wing)- negative angle control surfaces(move upward more than down) 2) Limited elevator down force capabilitywill prevent deep stall ofthe main wing. An Ercoupe is never really ableto deep stall the main wing much past the middle rootportion (non-accelerated stalls). It is reallyneat to demonstrate - yoke all the way back, decendingabout 600 fpm, but full control useage and about50 mph on the airspeed. Get a CFI withyou, and in a C152 and C172, you can get a 152to marginally stay stable if you keep ball centeredwith the rudder, but a spin will happen quickly witha little more induced stall with power to push thetail down or just kick the rudder a little. A C172 is anotheranimal. It has a little more elevator andwell, you know the rest of the story. You can getmore main wing stall with it and quicker results. 3) Dihedral angle can help, but not alwaystrue. Sometimesit actually worsens the tendancy forsingle wing deep stall.I would be interested in reading the sources, if youhappen to know where to find them. I believe the abovewill most likely be the reason why you will ALWAYSseewings with methods implemented for the tips to stall last.Remember - No plane will stall-spin unless a stall occurs first! (Only for a CFIlicense does one everhave to show proof of spinningan airplane for a license certificate...)David ScottWashington, ILMike Bell wrote:I thought that washout was to keep your tips fromstalling beforeyour wing root and therefore provide a modicum of spin protectionand stability at the start of a stall. If you want an aerobaticPeietenpol (oxymoron) then you would bend your tips up a littleinstead and promote tip stalling. NASA designed awing with amore aggressive airfoil at the tips that was "spin proof". Iwonder why I've never seen it on a production or experimentalaircraft?I haven't received my plans yet. How do you set washout on thePiet? Is it built in or do you tighten and loosen support/dragcables?Mike Bell (NoPietYet)Columbia, SClpasley lpasley(at)aristotle.net> on 05/06/99 10:41:01 PMPlease respond to Pietenpol Discussion piet(at)byu.edu>To: Pietenpol Discussion piet(at)byu.edu>cc:Subject: Pietenpol-List: Re: washoutThanks to you and Dean Dalton for the information. It'sappreciated. NowI'll try to get it set up right.Larry> >Dear Sirs,> >Can anyone tell me what wing wash out should be - or could be- on a GN-1> >with no dihedral? I'm having a time finding anything on this.I'd> >appreciate your help.> >Larry Pasley>> Larry- the wise older gentlemen where I fly (who rebuild andrig Cubs,> Champs,> etc.) suggested I put 3/8" washout about 3 ribs in from thewingtip. Iguess> it keeps the ailerons working longer as you begin to stall.> Mike C.-----------1---------2---------3---------4---------5---------6---------7/-------------------- |~~_____/~~__ ||DAVID SCOTT |______ ______====== )-+|scott(at)haulpak.com | o' ~~|~~~ |--------------------/ (O)________________________________________________________________________________

Original Posted By: Mike Bell
HelloI haven't been following the entire thread, I may have missed some thingbut you would anErcoupe have no aileron control during landing in a cross wind? I owneda 1946 Ercoupe for 10years, few it many hundreds of hours and it was the easiest airplane Iever landed in a cross wind.The aileron were coupled to the rudder, no cross control to preventstalling. All you had to do wasget your ground track strait down the runway, forget about were the nosewas pointed. Once downthe on the mains, point the nose down the runway, easy. The stalls arevery mild. I could pull thepower all the way off, pull the wheel/stick all the way back and mushdown with full aileroncontrol. I loved my Ercoupe, hope to have another one once I get my Pietfinished.Mike Madrid -----Original Message-----

Original Posted By: Wkoucky(at)aol.com
Mike, you want your tips to stall last so that you have good control inslow flight (aelerons are still functional). I remember well that youuse rudder to lift a wing in a stall, not aelerons). An attempt torecover with aelerons from a spin can delay or make recovery worse. Ifthe wing root stalls first, the break is more gradual, and recovery isis easier (neutal aelerons). Any attempt to use aelerons to recover adropped wing at the stall causes a failure of your check ride. InCanada, spin recovery is mandatory to get your licence.________________________________________________________________________________

Original Posted By: Ken Beanlands
I think you have mistaken the "deep stall" phenomena. The deep stallsare usually associated with T or high mounted verticalstabalizers/elevators. The normal down pitch after a stall is due to thefact that the elevator/stab is still capable of providing somestabalizing force even after the wing has stopped producing lift. If, forsome reason, the stabalizer becomes ineffective, the plane will continueto descend in a nose high, full stall attitude. This can occur on a T-tailplane or any plane where the tail is 5-15 degrees above the chordline ofthe wing. The turbulent air from the stalled wing will "mask " theelevator and stabalizer making it ineffective. At this point, onlyvigerous application of power, elevators and flaps can help break from thestall. You can see the result of this on an F-4 Phantom. Even though it's not aT-tail, the delta wing and engine outlet put the root of the stabilatorsin the deep stall position. You will note that the stabilators have a veryprnounced down angle to get them out of the wing shadow.Actually, the prototype Canadair 601 Challenger was lost in just thismanner. The test plane had been equipped with an emergency drouge chuteattached to the last bulkhead inside the tailcone. Sure enough, a deepstall developed and the test pilot fired the chute which pulled it out ofthe stall. Unfortunately, the explosive bolts used to attach the chute tothe plane malfunctioned and the chute could not be cut. All of the crewbailed out except the pilot. He almost recovered the plane but ran out ofheight and impacted the desert floor. It was speculated that with another300-500', he may have recovered enough to land it. The pilot was killedinstantly. KenOn Fri, 7 May 1999, David Scott wrote:> 2) Limited elevator down force capability will prevent> > > 3) Dihedral angle can help, but not always true.________________________________________________________________________________

Original Posted By: Doug
Yes and no. True, you hear all sorts of people complaining of a "heavywing". However, for the most part, these are wings that haven't beenrigged properly or have been built/rebuilt with a twist. our Cessna 180has an 88 gallon fuel capacity, that's 44 per wing or 264 lbs. Even withover 100 lbs differential between the wings (yeah, even with BOTH on theselector, one tank always drains quicker) the difference in flightcharacteristics is almost unnoticable. Heck, I've even flown with a 65 lb,16' canoe strapped to one float and it still tracked almost perfect. On the other hand, the PA-28 Cherokee had a distinct spin recoveryproblem when the weight differential was too great. This prompted theinstallation of "tabs" in the filler necks. If the fuel was above thetabs, you don't spin. If the fuel is below the tabs, there is not enoughfuel in either tank to exceed the differential needed to duplicate theproblem.However, I don't think that the few pounds in difference between thestructure of two wings will make much difference. KenOn Fri, 7 May 1999, Joe Krzes wrote:> When building the 3 pc wing, is it a good idea to make sure the wings weigh > the same? Our chapter had a discussion about building composite aircraft > and it turns out that if you build one wing in the winter and the other in > the summer (no climate control) then one wing will weigh more.> > Joe (reading the plans stage)> > >From: Craig Lawler > >Reply-To: Pietenpol Discussion > >To: Pietenpol Discussion > >Subject: Re: washout and stall> >Date: Fri, 07 May 1999 14:01:58 -0500> >> >Joe,> >> >I have about 1/4 of washout and have checked and rechecked alignment,> >but the right wing will mush and drop before the left. No clue why. Not> >a problem at all, I just know that's the way it is. It's a blast to slip> >to the left. Full rudder. Wing down low and if the right wing starts to> >drop a little just a couple hundred RPM picks it right up. To get into> >trouble you'd really have to force it.> >> >Craig> >> > > ________________________________________________________________________________

Original Posted By: oil can
In Canada,private pilots are trained in spins,and must demonstrate it onyour check ride.________________________________________________________________________________