Original Posted By: "Ken Chambers"
Pietenpol-List: more airfoil talk
Re: Pietenpol-List: more airfoil talk
Original Posted By: "DJ Vegh"
Subject: Re: Pietenpol-List: more airfoil talkKen,Am Interested in further airfoil talk. It has been my plan to build two sets of wings for 311CC for a little experimentation. I don't really have anything else to do and am hoping that I have enough time left to carry it out. I have acquired the stations and ordinates in % of chord for the wing airfoil NACA 2412. Strange you mention that one. It's high lift and less drag than the FC-10.Won't know for sure until Test Pilot Mr. Edwin Johnson gives me his report sometimes in 2005. Anyway it makes good conversation on the net and educates afew of us.Corky in La trying to give away his almost completed 1927 Dodge Bros Station Wagon ________________________________________________________________________________
Subject: Re: Pietenpol-List: more airfoil talkKen,Am Interested in further airfoil talk. It has been my plan to build two sets of wings for 311CC for a little experimentation. I don't really have anything else to do and am hoping that I have enough time left to carry it out. I have acquired the stations and ordinates in % of chord for the wing airfoil NACA 2412. Strange you mention that one. It's high lift and less drag than the FC-10.Won't know for sure until Test Pilot Mr. Edwin Johnson gives me his report sometimes in 2005. Anyway it makes good conversation on the net and educates afew of us.Corky in La trying to give away his almost completed 1927 Dodge Bros Station Wagon ________________________________________________________________________________
Re: Pietenpol-List: more airfoil talk
Original Posted By: Ken Chambers
Information on the NACA airfoils is pretty easy to get. Good luck finding anythingon BPs. That was why I suggested some wind tunnel testing by an Aero student.You can't do a comparison if you don't have data on all the airfoils. Best book to learn about aero theory I have found is by Abbott and Von Doenhoff.Gets a little deep every once in a while but fun to plow through.Hank J ----- Original Message -----
Information on the NACA airfoils is pretty easy to get. Good luck finding anythingon BPs. That was why I suggested some wind tunnel testing by an Aero student.You can't do a comparison if you don't have data on all the airfoils. Best book to learn about aero theory I have found is by Abbott and Von Doenhoff.Gets a little deep every once in a while but fun to plow through.Hank J ----- Original Message -----
Re: Pietenpol-List: more airfoil talk
Original Posted By: "Alex Sloan"
Subject: Re: Pietenpol-List: more airfoil talkIn a message dated 1/26/04 9:09:36 AM Central Standard Time, kchambers(at)winternals.com writes:>Ken,Where did you come up with the 'Pietenpol FC-10 ? The story goes...B.H.P. drew up the airfoil on the hanger floor. Original design.Chuck G.________________________________________________________________________________
Subject: Re: Pietenpol-List: more airfoil talkIn a message dated 1/26/04 9:09:36 AM Central Standard Time, kchambers(at)winternals.com writes:>Ken,Where did you come up with the 'Pietenpol FC-10 ? The story goes...B.H.P. drew up the airfoil on the hanger floor. Original design.Chuck G.________________________________________________________________________________
Re: Pietenpol-List: more airfoil talk
Original Posted By: "Jim Markle"
Subject: Re: Pietenpol-List: more airfoil talkIn a message dated 1/26/04 10:01:51 AM Central Standard Time, Isablcorky(at)aol.com writes:>Corky,Do you know where the FC-10 came from ?Chuck G.________________________________________________________________________________
Subject: Re: Pietenpol-List: more airfoil talkIn a message dated 1/26/04 10:01:51 AM Central Standard Time, Isablcorky(at)aol.com writes:>Corky,Do you know where the FC-10 came from ?Chuck G.________________________________________________________________________________
Re: Pietenpol-List: more airfoil talk
Original Posted By: "Ken Chambers"
Pietenpol-List: Re: more airfoil talk
Original Posted By: "dpaul"
If you need information about the 2412 or the 4412 airfoil, download reportnumber 824 from the NACA server (Google "NACA Server", should be the firstchoice). It's a pretty big file so start the download and go get a sandwichand some coffee.By general notation, a positive pitching moment is one that rotates theleading edge up. As a reference point, the 25% cord point is used as thepoint of rotation. You will notice on the airfoil sectional graphs, themoments are given as negitive and therefore are rotating the wing sectionleading edge down. This does not necessarily rotate the aircraft nose down,this simply means that the center of lift is aft of the 25% cord point.Rotating the aircraft nose down has to do with the relationship of thecenter of lift to the CG of the aircraft. On conventional aircraft (wingsin front, tail in back pushing down to keep the nose up) the CG is locatedahead of the center of lift (for stability purposes) and therefore thecenter of lift will rotate the nose down. On a carnard aircraft or aconventional aircraft that is loaded incorrectly, the CG will be behind thecenter of lift and the opposite will be true.Also noted from those wing sectional graphs, they range from -6 degrees AOAor less to 18 degrees or greater. A wing on an aircraft won't see thoseextremes in normal flight, so for design purposes, you need to use somethinglike 1 to 2 degrees in straight and level cruise to 14 degrees at the stallpoint to develop tail volume requirements.Also note that the center of lift does move along the wing at differentAOAs. Generally speaking, the center of lift is at the center to rear ofthe wing during straight and level and approaches the 25% cord point atstall. Determining where it is at stall (28% cord? 30% cord?) determinesthe aft CG limit.Although I am just another engineer puking information (that's what we do)and as interesting experimenting with the design would be, it must be notedthat this design AS IS has proved itself to be a wonderful combination andit has a flying personality all its own (I must admit that this is take fromthe opinions of others having not yet experienced it myself). If one wantssomething that flys like a Cessna... rent a Cessna. But then again, it isan EXPERIMENTAL aircraft.Sorry for the long winded lesson.Robert HainesDu Quoin, Illinois________________________________________________________________________________
If you need information about the 2412 or the 4412 airfoil, download reportnumber 824 from the NACA server (Google "NACA Server", should be the firstchoice). It's a pretty big file so start the download and go get a sandwichand some coffee.By general notation, a positive pitching moment is one that rotates theleading edge up. As a reference point, the 25% cord point is used as thepoint of rotation. You will notice on the airfoil sectional graphs, themoments are given as negitive and therefore are rotating the wing sectionleading edge down. This does not necessarily rotate the aircraft nose down,this simply means that the center of lift is aft of the 25% cord point.Rotating the aircraft nose down has to do with the relationship of thecenter of lift to the CG of the aircraft. On conventional aircraft (wingsin front, tail in back pushing down to keep the nose up) the CG is locatedahead of the center of lift (for stability purposes) and therefore thecenter of lift will rotate the nose down. On a carnard aircraft or aconventional aircraft that is loaded incorrectly, the CG will be behind thecenter of lift and the opposite will be true.Also noted from those wing sectional graphs, they range from -6 degrees AOAor less to 18 degrees or greater. A wing on an aircraft won't see thoseextremes in normal flight, so for design purposes, you need to use somethinglike 1 to 2 degrees in straight and level cruise to 14 degrees at the stallpoint to develop tail volume requirements.Also note that the center of lift does move along the wing at differentAOAs. Generally speaking, the center of lift is at the center to rear ofthe wing during straight and level and approaches the 25% cord point atstall. Determining where it is at stall (28% cord? 30% cord?) determinesthe aft CG limit.Although I am just another engineer puking information (that's what we do)and as interesting experimenting with the design would be, it must be notedthat this design AS IS has proved itself to be a wonderful combination andit has a flying personality all its own (I must admit that this is take fromthe opinions of others having not yet experienced it myself). If one wantssomething that flys like a Cessna... rent a Cessna. But then again, it isan EXPERIMENTAL aircraft.Sorry for the long winded lesson.Robert HainesDu Quoin, Illinois________________________________________________________________________________
RE: Pietenpol-List: more airfoil talk
Original Posted By: owner-pietenpol-list-server(at)matronics.com
Just my $0.02 worth, I believe the NACA 2412 was the airfoil Cessna used onthe Cessna 120/140. From personal experience with my 1947 140 I can attestto the fact that it is a fast, clean airfoil with a good glide (I measuredclose to a 20:1 glide ratio solo in my 140). It also was a dismal performerclimbing out with a load on a hot summer day. Every takeoff from a 2,000'grass trip in the summertime was a botany study, and I became intimatelyfamiliar with the trees at the end of the runway. I don't think I wouldcall it a high-lift airfoil. I think I'll stick with BHP's airfoil. Evenif you could greatly reduce the induced drag from the airfoil, there is somuch parasite drag on this airplane that I doubt you would get much morespeed out of it, and you would likely lose the good qualities. If you wantmore performance, build an RV.Jack-----Original Message-----
Just my $0.02 worth, I believe the NACA 2412 was the airfoil Cessna used onthe Cessna 120/140. From personal experience with my 1947 140 I can attestto the fact that it is a fast, clean airfoil with a good glide (I measuredclose to a 20:1 glide ratio solo in my 140). It also was a dismal performerclimbing out with a load on a hot summer day. Every takeoff from a 2,000'grass trip in the summertime was a botany study, and I became intimatelyfamiliar with the trees at the end of the runway. I don't think I wouldcall it a high-lift airfoil. I think I'll stick with BHP's airfoil. Evenif you could greatly reduce the induced drag from the airfoil, there is somuch parasite drag on this airplane that I doubt you would get much morespeed out of it, and you would likely lose the good qualities. If you wantmore performance, build an RV.Jack-----Original Message-----
Re: Pietenpol-List: more airfoil talk
Original Posted By: Mike
Subject: Re: Pietenpol-List: more airfoil talk
Subject: Re: Pietenpol-List: more airfoil talk
Re: Pietenpol-List: more airfoil talk
Original Posted By: Clif Dawson
anVzdCBhIGZhY3RvaWQgLi4uLi4udGhlIENlc3NuYSA0NDEgQ29ucXVlc3QgSUkgdHVyYm9wcm9wIGFsc28gdXNlcyB0aGUgTkFDQSAyNDEyLiANCg0KDQpESiBWZWdoDQpONzREVg0KTWVzYSwgQVoNCnd3dy5pbWFnZWR2LmNvbS9haXJjYW1wZXINCg0KDQoNCi0NCg0KICAtLS0tLSBPcmlnaW5hbCBNZXNzYWdlIC0tLS0tIA0KICBGcm9tOiBKYWNrIFBoaWxsaXBzIA0KICBUbzogcGlldGVucG9sLWxpc3RAbWF0cm9uaWNzLmNvbSANCiAgU2VudDogVGh1cnNkYXksIEphbnVhcnkgMjksIDIwMDQgNTo0NyBQTQ0KICBTdWJqZWN0OiBSRTogUGlldGVucG9sLUxpc3Q6IG1vcmUgYWlyZm9pbCB0YWxrDQoNCg0KICBKdXN0IG15ICQwLjAyIHdvcnRoLCBJIGJlbGlldmUgdGhlIE5BQ0EgMjQxMiB3YXMgdGhlIGFpcmZvaWwgQ2Vzc25hIHVzZWQgb24gdGhlIENlc3NuYSAxMjAvMTQwLiBGcm9tIHBlcnNvbmFsIGV4cGVyaWVuY2Ugd2l0aCBteSAxOTQ3IDE0MCBJIGNhbiBhdHRlc3QgdG8gdGhlIGZhY3QgdGhhdCBpdCBpcyBhIGZhc3QsIGNsZWFuIGFpcmZvaWwgd2l0aCBhIGdvb2QgZ2xpZGUgKEkgbWVhc3VyZWQgY2xvc2UgdG8gYSAyMDoxIGdsaWRlIHJhdGlvIHNvbG8gaW4gbXkgMTQwKS4gIEl0IGFsc28gd2FzIGEgZGlzbWFsIHBlcmZvcm1lciBjbGltYmluZyBvdXQgd2l0aCBhIGxvYWQgb24gYSBob3Qgc3VtbWVyIGRheS4gIEV2ZXJ5IHRha2VvZmYgZnJvbSBhIDIsMDAwJyBncmFzcyB0cmlwIGluIHRoZSBzdW1tZXJ0aW1lIHdhcyBhIGJvdGFueSBzdHVkeSwgYW5kIEkgYmVjYW1lIGludGltYXRlbHkgZmFtaWxpYXIgd2l0aCB0aGUgdHJlZXMgYXQgdGhlIGVuZCBvZiB0aGUgcnVud2F5LiAgSSBkb24ndCB0aGluayBJIHdvdWxkIGNhbGwgaXQgYSBoaWdoLWxpZnQgYWlyZm9pbC4gIEkgdGhpbmsgSSdsbCBzdGljayB3aXRoIEJIUCdzIGFpcmZvaWwuICBFdmVuIGlmIHlvdSBjb3VsZCBncmVhdGx5IHJlZHVjZSB0aGUgaW5kdWNlZCBkcmFnIGZyb20gdGhlIGFpcmZvaWwsIHRoZXJlIGlzIHNvIG11Y2ggcGFyYXNpdGUgZHJhZyBvbiB0aGlzIGFpcnBsYW5lIHRoYXQgSSBkb3VidCB5b3Ugd291bGQgZ2V0IG11Y2ggbW9yZSBzcGVlZCBvdXQgb2YgaXQsIGFuZCB5b3Ugd291bGQgbGlrZWx5IGxvc2UgdGhlIGdvb2QgcXVhbGl0aWVzLiAgSWYgeW91IHdhbnQgbW9yZSBwZXJmb3JtYW5jZSwgYnVpbGQgYW4gUlYuDQoNCiAgIA0KDQogIEphY2sNCg0KICAgDQoNCiAgLS0tLS1PcmlnaW5hbCBNZXNzYWdlLS0tLS0NCiAgRnJvbTogb3duZXItcGlldGVucG9sLWxpc3Qtc2VydmVyQG1hdHJvbmljcy5jb20gW21haWx0bzpvd25lci1waWV0ZW5wb2wtbGlzdC1zZXJ2ZXJAbWF0cm9uaWNzLmNvbV1PbiBCZWhhbGYgT2YgaGphcnJldHQNCiAgU2VudDogTW9uZGF5LCBKYW51YXJ5IDI2LCAyMDA0IDg6MjcgUE0NCiAgVG86IHBpZXRlbnBvbC1saXN0QG1hdHJvbmljcy5jb20NCiAgU3ViamVjdDogUmU6IFBpZXRlbnBvbC1MaXN0OiBtb3JlIGFpcmZvaWwgdGFsaw0KDQogICANCg0KICBJbmZvcm1hdGlvbiBvbiB0aGUgTkFDQSBhaXJmb2lscyBpcyBwcmV0dHkgZWFzeSB0byBnZXQuICBHb29kIGx1Y2sgZmluZGluZyBhbnl0aGluZyBvbiBCUHMuICBUaGF0IHdhcyB3aHkgSSBzdWdnZXN0ZWQgc29tZSB3aW5kIHR1bm5lbCB0ZXN0aW5nIGJ5IGFuIEFlcm8gc3R1ZGVudC4gIFlvdSBjYW4ndCBkbyBhIGNvbXBhcmlzb24gaWYgeW91IGRvbid0IGhhdmUgZGF0YSBvbiBhbGwgdGhlIGFpcmZvaWxzLiAgQmVzdCBib29rIHRvIGxlYXJuIGFib3V0IGFlcm8gdGhlb3J5IEkgaGF2ZSBmb3VuZCBpcyBieSBBYmJvdHQgYW5kIFZvbiBEb2VuaG9mZi4gIEdldHMgYSBsaXR0bGUgZGVlcCBldmVyeSBvbmNlIGluIGEgd2hpbGUgYnV0IGZ1biB0byBwbG93IHRocm91Z2guDQoNCiAgSGFuayBKDQoNCiAgLS0tLS0gT3JpZ2luYWwgTWVzc2FnZSAtLS0tLSANCg0KDQogIEZyb206IEtlbiBDaGFtYmVycyANCg0KICBUbzogcGlldGVucG9sLWxpc3RAbWF0cm9uaWNzLmNvbSANCg0KICBTZW50OiBNb25kYXksIEphbnVhcnkgMjYsIDIwMDQgMTA6MDcgQU0NCg0KICBTdWJqZWN0OiBQaWV0ZW5wb2wtTGlzdDogbW9yZSBhaXJmb2lsIHRhbGsNCg0KICAgDQoNCiAgSSd2ZSBwb2tlZCBhcm91bmQgYSBsaXR0bGUgb24gdGhlIEludGVybmV0LCB0cnlpbmcgdG8gd2Vhc2VsIHNvbWUgYWlyZm9pbCByZWNvbW1lbmRhdGlvbnMgZnJvbSBrbm93bGVkZ2VhYmxlIGZvbGsuIEp1c3QgdG8ga2VlcCB1cyB0YWxraW5nIGFib3V0IGl0LCBnaXZlIHVzIHNvbWUgaWRlYXMuIERhdmlkIExlZG5pY2VyLCB3aG8gc2VlbXMgdG8gaGF2ZSBzb21lIHByZXR0eSBuaWNlIGFlcm9keW5hbWljIGJvbmEgZmlkZXMgYW5kIHdvcmtzIGZvciBBbmFseXRpY2FsIE1ldGhvZHMsIEluYy4sIHRoaW5rcyB3ZSBzaG91bGQga2VlcCBpdCBzaW1wbGUgd2l0aCBOQUNBIDI0MTIgb3IgNDQxMi4gUHJvdmVuIGFpcmZvaWxzIHdpdGggd2VsbC1rbm93biBjaGFyYWN0ZXJpc3RpY3MuIFVzZWQgZm9yIHllYXJzIGluIGEgdmFyaWV0eSBvZiBDZXNzbmFzIGFuZCBvdGhlciBhaXJjcmFmdC4NCg0KICAgDQoNCiAgSSBoYXZlbid0IGhhZCBhIGNoYW5jZSB0byBmaW5kIHRoZSBzdGF0cyBmb3IgdGhlc2UgYWlyZm9pbHMgc28gd2UgY2FuIGNvbXBhcmUgdGhlbSB0byB0aGUgUGlldGVucG9sIEZDLTEwLiBBbnlvbmUga25vdyB3aGVyZSB0byBmaW5kIHRoaXMgaW5mb3JtYXRpb24gb25saW5lPyANCg0KICAgDQoNCiAgS2VuDQoNCiAgIA0K________________________________________________________________________________Date: Thu, 29 Jan 2004 23:16:39 -0800
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________________________________________________________________________________Date: Thu, 29 Jan 2004 23:16:39 -0800
Pietenpol-List: Re: more airfoil talk
Original Posted By: "Jim Markle"
more airfoil talk________________________________________________________________________________
more airfoil talk________________________________________________________________________________
Pietenpol-List: Re: more airfoil talk
Original Posted By: Isablcorky(at)aol.com
I hope I'm not the only one that encourages this, but if Corky is thinkingabout building a 2412 (or similar) airfoil as an experiment to see whathappens, I say go for it! Some of us like plowing through technical manualsand trying to optomise down to the nats ass on design, but then again, someof us just like to build and see. As long as anyone doesn't see anythinghorribly unsafe with the wing section selection, I would like to beencouraging on this one. It is an experimental aircraft for crying outloud, and some of the fun is in the experimenting.Also, when (not if) Corky flys his planes, he's going to need a little speedto get from LA to WI to show it off. Heck now that I've said that, I thinkit would be cool to have multiple wings (the standard set, a pair ofspeeders, a super high lift set, etc.), depending on the day's application.It would be the Swiss army knife of AirCampers.Robert HainesDu Quoin, Illinois
I hope I'm not the only one that encourages this, but if Corky is thinkingabout building a 2412 (or similar) airfoil as an experiment to see whathappens, I say go for it! Some of us like plowing through technical manualsand trying to optomise down to the nats ass on design, but then again, someof us just like to build and see. As long as anyone doesn't see anythinghorribly unsafe with the wing section selection, I would like to beencouraging on this one. It is an experimental aircraft for crying outloud, and some of the fun is in the experimenting.Also, when (not if) Corky flys his planes, he's going to need a little speedto get from LA to WI to show it off. Heck now that I've said that, I thinkit would be cool to have multiple wings (the standard set, a pair ofspeeders, a super high lift set, etc.), depending on the day's application.It would be the Swiss army knife of AirCampers.Robert HainesDu Quoin, Illinois
Re: Pietenpol-List: more airfoil talk
Original Posted By: "John Ford"
Pietenpol-List: Re: more airfoil talk
Original Posted By: "Robert Haines"
Oh yea, and another thing (oh, now I'm started), what the heck is with thisconcern for changing the wing section?! "Oh My, you can possibly change thewing, it just won't be an original!"You can change the fuselage, heck the plans give you three choices, someeven change it beyond that. You can put whatever engine in it, the cowlingsare different from plane to plane... Wheels and gear, got a few choicesthere... some have passenger doors... struts as opposed to rigging wires...to flop or not to flop... three piece wing or one big slab... turtle deck.But HEAVEN FORBID that the wing section get changed! Gesh, you thought wewere talking about rounding the lines of the tail (that, of course you cannot do, it would just be silly).Whew.Robert HainesDu Quoin, Illinois:)----- Original Message -----
Oh yea, and another thing (oh, now I'm started), what the heck is with thisconcern for changing the wing section?! "Oh My, you can possibly change thewing, it just won't be an original!"You can change the fuselage, heck the plans give you three choices, someeven change it beyond that. You can put whatever engine in it, the cowlingsare different from plane to plane... Wheels and gear, got a few choicesthere... some have passenger doors... struts as opposed to rigging wires...to flop or not to flop... three piece wing or one big slab... turtle deck.But HEAVEN FORBID that the wing section get changed! Gesh, you thought wewere talking about rounding the lines of the tail (that, of course you cannot do, it would just be silly).Whew.Robert HainesDu Quoin, Illinois:)----- Original Message -----
Pietenpol-List: Re: more airfoil talk
Original Posted By: Rcaprd(at)aol.com
> it would be cool to have multiple wings (the standard set, a pair of> speeders, a super high lift set, etc.), depending on the day'sapplication.> It would be the Swiss army knife of AirCampers.The heck with this 3-piece wing stuff. How about a 12-piece wing. Just pickthe speed you want to fly and take off as many sections as you dare. Whenyou can't lift off anymore, you went one step too far. :)________________________________________________________________________________
> it would be cool to have multiple wings (the standard set, a pair of> speeders, a super high lift set, etc.), depending on the day'sapplication.> It would be the Swiss army knife of AirCampers.The heck with this 3-piece wing stuff. How about a 12-piece wing. Just pickthe speed you want to fly and take off as many sections as you dare. Whenyou can't lift off anymore, you went one step too far. :)________________________________________________________________________________
Re: Pietenpol-List: Re: more airfoil talk
Original Posted By: dave rowe
Subject: Re: Pietenpol-List: Re: more airfoil talkCorky, Robert, et all, When you change anything in an aircraft design, you will change a host of other things, especially if it's the airfoil that you consider changing. The 'French Curve, Ten Minute' (FC-10) airfoil has been designed into the Pietenpol for very good reasons. It allows the C.G. to be further aft, than anyairfoil that is not undercambered. It's a High Lift airfoil, that allows a lowpower engine to be used. The down side of the high lift, is that it is High Drag. The overall high drag of the Pietenpol also has it's advantages...it'sdifficult to achieve a high enough speed for flutter to occur. None of the flight control surfaces of a Pietenpol are mass balanced. If a more efficient airfoil is used on the Pietenpol, higher speed will result. This higher speed, will certainly approach the speed at which one of the control surfaces will flutter. B.H.P. called out the Vne of the Piet at 90 m.p.h., and must be adhered to. On three separate occations, I've wittnessed a model R.C. airplane flutter one of the control surfaces. I could hear the sound - z z z Z Z Z Z asit went past, and it took just a couple of seconds before the control surface toreitself loose from the plane, and the plane crashed into hundreds of pieces. On two separate occasions, I've witnessed the results of an aft C.G. on a model R.C. airplane. These two planes were of aerobatic design, and maintaining the C.G. at the aft limits allows the plane to be Very agile, and alsoincreases it's efficiency. Both times, the pilot thought he would be all rightwith the C.G. just a tiny bit behind the aft limit, and after entering a spin,the plane would not come out of the spin, no matter what the pilot did with the stick or power setting, and the model airplane spun all the way to the ground, with disastrous results. The Grega G1 has a larger radius on the leading edge, in an attempt to soften the stall break. It's actually the rapid increase in 'Induced Drag' thatcauses the Pietenpol to slow down quickly, and surpass the 'Critical Angle of Attack. 'Parasite Drag' is at it's minimum during the slow flight of the Landing. On prototype certified aircraft, they have some underpaid experimental test pilot, take the plane up for flutter tests. He dives it, in incremental speed increases, until one of the control surfaces begins to flutter, and immediately pulls power and eases the nose up, to slow down. If his prayers areanswered, the control surface will still be attached to the aircraft. The designer then reduces this speed by 25%, and this is the Vne of the aircraft. If anything is changed to any of the flight control system, these flutter tests must be re-done. Steve Wittman did these flutter tests on his design, down very close to the frozen Lake Michigan. If a control surface would flutter andcome off, he would land at a very high speed, and slide to a stop. I don't believe it ever did happen, though. Talk about Big Kahoona's !!!! I am all for experimenting, and learning as much as possible as to why things are designed the way they are, but you must understand all the consequences before you make any changes to the aircraft.Chuck GantzerNX770CG________________________________________________________________________________Date: Sat, 31 Jan 2004 21:11:44 -0800
Subject: Re: Pietenpol-List: Re: more airfoil talkCorky, Robert, et all, When you change anything in an aircraft design, you will change a host of other things, especially if it's the airfoil that you consider changing. The 'French Curve, Ten Minute' (FC-10) airfoil has been designed into the Pietenpol for very good reasons. It allows the C.G. to be further aft, than anyairfoil that is not undercambered. It's a High Lift airfoil, that allows a lowpower engine to be used. The down side of the high lift, is that it is High Drag. The overall high drag of the Pietenpol also has it's advantages...it'sdifficult to achieve a high enough speed for flutter to occur. None of the flight control surfaces of a Pietenpol are mass balanced. If a more efficient airfoil is used on the Pietenpol, higher speed will result. This higher speed, will certainly approach the speed at which one of the control surfaces will flutter. B.H.P. called out the Vne of the Piet at 90 m.p.h., and must be adhered to. On three separate occations, I've wittnessed a model R.C. airplane flutter one of the control surfaces. I could hear the sound - z z z Z Z Z Z asit went past, and it took just a couple of seconds before the control surface toreitself loose from the plane, and the plane crashed into hundreds of pieces. On two separate occasions, I've witnessed the results of an aft C.G. on a model R.C. airplane. These two planes were of aerobatic design, and maintaining the C.G. at the aft limits allows the plane to be Very agile, and alsoincreases it's efficiency. Both times, the pilot thought he would be all rightwith the C.G. just a tiny bit behind the aft limit, and after entering a spin,the plane would not come out of the spin, no matter what the pilot did with the stick or power setting, and the model airplane spun all the way to the ground, with disastrous results. The Grega G1 has a larger radius on the leading edge, in an attempt to soften the stall break. It's actually the rapid increase in 'Induced Drag' thatcauses the Pietenpol to slow down quickly, and surpass the 'Critical Angle of Attack. 'Parasite Drag' is at it's minimum during the slow flight of the Landing. On prototype certified aircraft, they have some underpaid experimental test pilot, take the plane up for flutter tests. He dives it, in incremental speed increases, until one of the control surfaces begins to flutter, and immediately pulls power and eases the nose up, to slow down. If his prayers areanswered, the control surface will still be attached to the aircraft. The designer then reduces this speed by 25%, and this is the Vne of the aircraft. If anything is changed to any of the flight control system, these flutter tests must be re-done. Steve Wittman did these flutter tests on his design, down very close to the frozen Lake Michigan. If a control surface would flutter andcome off, he would land at a very high speed, and slide to a stop. I don't believe it ever did happen, though. Talk about Big Kahoona's !!!! I am all for experimenting, and learning as much as possible as to why things are designed the way they are, but you must understand all the consequences before you make any changes to the aircraft.Chuck GantzerNX770CG________________________________________________________________________________Date: Sat, 31 Jan 2004 21:11:44 -0800
Re: Pietenpol-List: Re: more airfoil talk
Original Posted By: "Lauritz Larsen"
Subject: Re: Pietenpol-List: Re: more airfoil talkHave you ever read about Jimmy Doolittle's test flight of a highly modified Travel Air Mystery ship? The airplane, owned by Shell Oil Company, was taken to Parks College in St. Louis for refurb.... I think in 1931 or 1932. They did an aerodynamic clean-up adding sweeping wing filet fairings, and other changes, including an airfoil mod. The first flight lasted about 30 minutes withJimmy Doolittle at the controls. He climbed to approx 5000ft. and joined up with a camera ship. One in-flight picture was taken as far as I have ever seen. Jimmy claimed the "Shell 400" was performing so well that he decided to do a high speed pass over the field. At an altitiude of less than 50 ft, aileron flutter set in so bad that Doolittle had no choice but to pull up and bail out. His Parachute flight was said to be the lowest on record up to that time.Lucky that the canopy opened in time. The second picture of the "Shell 400" that I know of is of the mangled twisted wreckage.I don't know about you guys, but I feel that its going to take some biig cahoooonas for me to climb into the Piet for that first flight. I would wear a'Chute, but I doubt I could fit in the cockpit with it, much less pry myself loose to bail out if anything happened. Go ahead and do your research and experiment with another airfoil if you must. But I'll pass. I'd much rather testmy airplane with the known FC-10.my $ .02 TLB________________________________________________________________________________
Subject: Re: Pietenpol-List: Re: more airfoil talkHave you ever read about Jimmy Doolittle's test flight of a highly modified Travel Air Mystery ship? The airplane, owned by Shell Oil Company, was taken to Parks College in St. Louis for refurb.... I think in 1931 or 1932. They did an aerodynamic clean-up adding sweeping wing filet fairings, and other changes, including an airfoil mod. The first flight lasted about 30 minutes withJimmy Doolittle at the controls. He climbed to approx 5000ft. and joined up with a camera ship. One in-flight picture was taken as far as I have ever seen. Jimmy claimed the "Shell 400" was performing so well that he decided to do a high speed pass over the field. At an altitiude of less than 50 ft, aileron flutter set in so bad that Doolittle had no choice but to pull up and bail out. His Parachute flight was said to be the lowest on record up to that time.Lucky that the canopy opened in time. The second picture of the "Shell 400" that I know of is of the mangled twisted wreckage.I don't know about you guys, but I feel that its going to take some biig cahoooonas for me to climb into the Piet for that first flight. I would wear a'Chute, but I doubt I could fit in the cockpit with it, much less pry myself loose to bail out if anything happened. Go ahead and do your research and experiment with another airfoil if you must. But I'll pass. I'd much rather testmy airplane with the known FC-10.my $ .02 TLB________________________________________________________________________________
Pietenpol-List: Re: more airfoil talk
Original Posted By:> BARNSTMR(at)aol.com
Well, yea, that's the exact attitude you should have with any unprovenaircraft, even one with the FC-10 airfoil. There are hundreds of thingsthat can go wrong, you should always try to completely understand all therisks and develop plans to mitigate them. Yes, one would be to use a provenairfoil, that would be one less risk, no argument there. But let me ask,how exactly did Bernie develop this airfoil? Did he pour through endlesswing section diagrams, did he develop remote control models, did he runcomputer analysis or do wind tunnel test? As I understand, he made severalsets of wings and tried them all out on the plane, and then decided on theone he liked best. As the story goes, he spent all of 10 minutes drawingthat one out.I am not advocating any unsafe methodology to procede with the design,development, and construction of an aircraft. I also think to many peoplefoolhartedly proceed with an existing design and just "burn-off" the flighthours required in the initial testing phase. Simply because this design isproven over and over, does not mean that your new aircraft is free from thescrutiny required for any new experimental aircraft, and I would stronglysuggest that you initially fly the plane as if it were about to experienceany sort of catastrophic failure.Regarding the comments to wing flutter: yes, flutter is a likely event whenincreasing the speed of an aircraft with unbalanced control surfaces.Although, how many who have considered that putting in more powerfulengines, providing covers over the wheels, or streamlining any other areawould increase the speed of the aircraft to a point that the controlsurfaces would flutter? I haven't heard one word. Not to say that it wouldor wouldn't, and I hope I don't sound like I'm lecturing, but my point isthat changes in design always have to be taken with a strong considerationto the consequences. Changing the airfoil is just simply another one ofthose things that you must provide a concious effort to seek out the resultsof said change and that's how you proceed with an EXPERIMENTAL aircraft.OK, getting off soapbox now. Thank you for your support.Robert HainesDu Quoin, Illinois
Well, yea, that's the exact attitude you should have with any unprovenaircraft, even one with the FC-10 airfoil. There are hundreds of thingsthat can go wrong, you should always try to completely understand all therisks and develop plans to mitigate them. Yes, one would be to use a provenairfoil, that would be one less risk, no argument there. But let me ask,how exactly did Bernie develop this airfoil? Did he pour through endlesswing section diagrams, did he develop remote control models, did he runcomputer analysis or do wind tunnel test? As I understand, he made severalsets of wings and tried them all out on the plane, and then decided on theone he liked best. As the story goes, he spent all of 10 minutes drawingthat one out.I am not advocating any unsafe methodology to procede with the design,development, and construction of an aircraft. I also think to many peoplefoolhartedly proceed with an existing design and just "burn-off" the flighthours required in the initial testing phase. Simply because this design isproven over and over, does not mean that your new aircraft is free from thescrutiny required for any new experimental aircraft, and I would stronglysuggest that you initially fly the plane as if it were about to experienceany sort of catastrophic failure.Regarding the comments to wing flutter: yes, flutter is a likely event whenincreasing the speed of an aircraft with unbalanced control surfaces.Although, how many who have considered that putting in more powerfulengines, providing covers over the wheels, or streamlining any other areawould increase the speed of the aircraft to a point that the controlsurfaces would flutter? I haven't heard one word. Not to say that it wouldor wouldn't, and I hope I don't sound like I'm lecturing, but my point isthat changes in design always have to be taken with a strong considerationto the consequences. Changing the airfoil is just simply another one ofthose things that you must provide a concious effort to seek out the resultsof said change and that's how you proceed with an EXPERIMENTAL aircraft.OK, getting off soapbox now. Thank you for your support.Robert HainesDu Quoin, Illinois