X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 02 Oct 2013 07:49:55 -0400 Message-ID: X-Original-Return-Path: Received: from nm41-vm6.bullet.mail.gq1.yahoo.com ([67.195.87.93] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with ESMTPS id 6498346 for lml@lancaironline.net; Tue, 01 Oct 2013 15:35:24 -0400 Received-SPF: none receiver=logan.com; client-ip=67.195.87.93; envelope-from=dudewanarace@yahoo.com Received: from [98.137.12.188] by nm41.bullet.mail.gq1.yahoo.com with NNFMP; 01 Oct 2013 19:33:39 -0000 Received: from [216.39.60.200] by tm9.bullet.mail.gq1.yahoo.com with NNFMP; 01 Oct 2013 19:33:39 -0000 Received: from [127.0.0.1] by omp1087.mail.gq1.yahoo.com with NNFMP; 01 Oct 2013 19:33:39 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 318834.22131.bm@omp1087.mail.gq1.yahoo.com Received: (qmail 82619 invoked by uid 60001); 1 Oct 2013 19:33:38 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Rocket-MIMEInfo:X-Mailer:Message-ID:Date:From:Reply-To:Subject:To:MIME-Version:Content-Type; b=OVZuCXWFWLnqaY7nM5H0aMzV3Vm04gIxhscM3f2YN0f51pymfGKo0fGPqspvIIwVfKkajnmxdomcVQoI/SmG+J8iiwkWNTpIqiAX3eLCnqxV0hvXgWlTbXzjm6+lRJlA2ptCsBFOV4t+ud20dQroUH6KlAe+Po4rrC3z1LacZUU=; X-YMail-OSG: p6nMz9UVM1nFs0Db.AdgvaObPcS6UVO329.19l4RtR8.OJ7 wfDCWSviKEgjXKV042hmSttKo5VNH.2MwhrEsIpry7cprzZeQNUXqXhLuNhM nE0dtwFh4TqE_sP8Xcr6qmM5OJjUN2_rIonFrf126TEjHvR8f2jzlchgKVxt w8t14f_PqvvJ89YMEp.seV8lq6Cq.UoJR3hpvO9tLSHLqX97wIJbmLQs5YO5 99_DxtLaN00Oil9DotDmBJDn6Jp9itTghBPF.gYYRoY5jopprZm6ELwhG0ON Yv8bstlUWtuvhdPahuzsHMfjU6TA_cPHFgqiwJQo1D9kGiVDGiC7o9HvhAma ukarYAgz2EKA2sf0QjwBlWEwakocX6_jsUC8wlrpxNEsW08Vo1N07elew9tN 6_BYRUQKO9EFRb2_kTGh9.xG903pWuUSA0FIZ4US4GnvVgYoDXzfndaxZKF5 H0fQ7UVDu5z3VB_GIF0PWM2bh9MQ6uDxaA8jA0W30EZj63kv2FZ64fG1fB47 TBZ3ecxkxtPP303keo8umB5u_UWXKja6cJTbT3QNjnZ_8ApXad4LsweqiL8y IuWT_WV85Y1ToUnzg3pK2psR1X3gKNlX1ZkMMEMwET4nCUBaIkuiK0KrJKvY v71Pj_oIb1vjkSkM6P0xlgeQzdfm6dV9BKS_ecoRESWF2hZq1ZFKJOkK0nP8 CFA-- Received: from [24.2.15.88] by web120904.mail.ne1.yahoo.com via HTTP; Tue, 01 Oct 2013 12:33:38 PDT X-Rocket-MIMEInfo: 002.001,UmVhZGVycywKSSBoYXZlIGJlZW4gd2F0Y2hpbmcgdGhpcyBjb252ZXJzYXRpb24gd2l0aCBpbnRlcmVzdC4gwqBJIGhhdmUgc29tZSBvZGQgZXhwZXJpZW5jZXMgd2l0aCBzdGFiaWxpdHkgaW4gbXkgc21hbGwgdGFpbCAzNjAgdGhhdCB3YXMgaW1wcm9wZXJseSBidWlsdCAobm90IGJ5IG1lKS4gwqBHZWV6LCB0aGF0IGlzIGdvaW5nIHRvIGh1cnQgcmVzYWxlLi4gaGFoYQoKQW55d2F5LCBJIGhhdmUgYmVlbiB3YWl0aW5nIHRvIGNvbW1lbnQgYXMgaXQgd2lsbCBqdXN0IGZvZyB0aGUgZGF0YSB0aGF0IGhhcyABMAEBAQE- X-Mailer: YahooMailWebService/0.8.160.587 X-Original-Message-ID: <1380656018.62647.YahooMailNeo@web120904.mail.ne1.yahoo.com> X-Original-Date: Tue, 1 Oct 2013 12:33:38 -0700 (PDT) From: dudewanarace@yahoo.com Reply-To: dudewanarace@yahoo.com Subject: 320/360 performance and stability X-Original-To: Lancair Mailing List MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-895799069-1236927741-1380656018=:62647" ---895799069-1236927741-1380656018=:62647 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Readers,=0AI have been watching this conversation with interest. =A0I have = some odd experiences with stability in my small tail 360 that was improperl= y built (not by me). =A0Geez, that is going to hurt resale.. haha=0A=0AAnyw= ay, I have been waiting to comment as it will just fog the data that has be= en presented given my totally odd arrangement and lack of any real data. = =A0All of my 'data' is seat of the pants, thus not worth mentioning. =A0But= , figured I could expand on an envelope probably few have visited just for = interesting reading.=0A=0AThis is my elevator angle with the airplane in a = forward C.G. condition (header fuel only, single pilot), flaps in reflex an= d, well, going as fast as an RV-7 will go in formation. :)=0Ahttp://www.n54= sg.com/images/tuft_test_08.jpg=0A=0A=0ASo, this problem poses a few issues.= =0AFirst, this is obviously drag, probably a measurable amount thus for me = the driving force behind correcting it one day. =A0Second is the available = elevator travel. =A0If you read the manual, I have the correct amount of up= / down elevator travel. =A0But, if the photo is my starting point, it mean= s I have much less up, and way too much down available to use. =A0The impor= tant part being the elevator up while in the flare. =A0Given a forward C.G.= and a huge amount of flaps, this can be an issue. (ask me how I know...)= =0A=0ANext I would like to mention that not all small tails trim the same. = =A0Some use a spring system to bias the entire elevator. =A0Others use trim= tabs. =A0I have a tab that due to its placement and odd elevator deflectio= n has a limited functional envelope. =A0Another driving force to change inc= idence.=0A=0ANow the often obvious question people ask is why haven't I fix= ed it yet. =A0Well, because the job of fixing it is going to totally suck, = and I wanted it to be the last thing I do as my other aerodynamic changes m= ay affect the angle of incidence. =A0This brings me to the next subject, wh= at I have changed.=0A=0ASo I have this airplane going faster than most and = figured why stop now.. I made a rather drastic change that some call the be= luga belly. =A0It has been done to a few Legacys that race with varied appl= ications of the same idea. =A0Those familiar with the 320/360 fuselage will= notice it in this picture:=0Ahttp://www.n54sg.com/images/tuft_test_04.jpg= =0A=0AI'm working on a write up for my website detailing the project and it= s purpose and will have that posted sometime soon. =A0But, I will report th= at this did change the downwash on my horiztonal and did change my required= angle of incidence. Hence, I'm glad I waited to change that. =A0It actuall= y requires less up elevator than it did before so less negative incidence. = =A0The general theory is I have corrected some flow around the fuselage thu= s making the entire horizontal a bit more effective. =A0Some modified Legac= ys experienced something similar. =A0I only wish it would have corrected it= more! =A0I now know more about this mod and maybe would have applied it di= fferently. =A0Just not sure I'm willing to do the work again for unknown ga= ins.=0A=0AThe other aerodynamic change I made (that relates to the original= stability post) is I removed the cusp from the bottom surface of my flaps = as suggested in a book about GA airfoils by Harry Riblett. =A0Below is a si= mplified version of his drawing. =A0(Not accurate, just for explanation pur= poses) =A0The solid black is the modification.=0Ahttp://www.n54sg.com/image= s/Flap_Drawing.jpg=0A=0ASo, what I have done to the camber of the wing is a= bit odd I suppose, but it was odd to start with. =A0Keep in mind, the 320 = / 360 ailerons already have this modification. =A0I didn't get the 10 kts I= thought I would. =A0(Aren't all mods worth 10 kts? haha) =A0But, it is a d= ifferent airfoil. =A0Stall was no different, but the pitch force did increa= se with flaps extended. =A0Not a bad thing in my opinion. =A0Overall it is = hard to explain, it is a different wing, just can't pinpoint how.=A0=0A=0AI= n the end I think I have made the airplane aerodynamically better, but I ha= ve moved the problem. =A0It seems with just a little bit cleaner airplane I= ran in to the limit of the propeller. =A0Previously more rpm always netted= more speed. =A0Now the top 250ish rpm doesn't do much at all. =A0Total bum= mer! =A0Having to learn a lot more about propellers than I ever thought I w= ould now...=0A=0AResults of my airplane at Reno this year:=0AQualifying: 26= 8.272 mph=0ASport Medallion: 1st 261.906 mph (only 2600 rpm!)=0AHeat 1C: 3r= d 268.300 mph=0AHeat 2C: 2nd 265.030 mph=0AHeat 3C: 2nd 266.717 mph=0ABronz= e Race: 2nd 266..944 mph=0A=0A=0AI have some really cool video from my helm= et/dash cameras, just trying to get it all edited. =A0Hear is a teaser of s= ome VERY close racing with Dave Morss in his Legacy: http://youtu.be/iegd6y= lVHI4=0ABest to watch in full screen in HD. =A0Keep in mind, objects in a w= ide angle lens are closer than they appear! haha=0A=0ATom McNerney=0Awww.N5= 4SG.com=A0=0A ---895799069-1236927741-1380656018=:62647 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
Readers,
I have been watchi= ng this conversation with interest.  I have some odd experiences with = stability in my small tail 360 that was improperly built (not by me).  = ;Geez, that is going to hurt resale.. haha

Anyway, I have been = waiting to comment as it will just fog the data that has been presented giv= en my totally odd arrangement and lack of any real data.  All of my 'd= ata' is seat of the pants, thus not worth mentioning.  But, figured I could expand on an envelope probably few have visited just for interesting= reading.

This is my elevator angle with the airplane in a forward= C.G. condition (header fuel only, single pilot), flaps in reflex and, well= , going as fast as an RV-7 will go in formation. :)
htt= p://www.n54sg.com/images/tuft_test_08.jpg

So, this p= roblem poses a few issues.
First, this is obviously drag, probably a measurable amount thus for m= e the driving force behind correcting it one day.  Second is the avail= able elevator travel.  If you read the manual, I have the correct amou= nt of up / down elevator travel.  But, if the photo is my starting poi= nt, it means I have much less up, and way too much down available to use. &= nbsp;The important part being the elevator up while in the flare.  Giv= en a forward C.G. and a huge amount of flaps, this can be an issue. (ask me= how I know...)
Next I would like to= mention that not all small tails trim the same.  Some use a spring sy= stem to bias the entire elevator.  Others use trim tabs.  I have = a tab that due to its placement and odd elevator deflection has a limited f= unctional envelope.  Another driving force to change incidence.=

Now the often obvious question people ask is why haven't I fixed = it yet.  Well, because the job of fixing it is going to totally suck, = and I wanted it to be the last thing I do as my other aerodynamic changes m= ay affect the angle of incidence.  This brings me to the next subject,= what I have changed.

So I have this airplane going faster than mo= st and figured why stop now.. I made a rather drastic change that some call= the beluga belly.  It has been done to a few Legacys that race with v= aried applications of the same idea.  Those familiar with the 320/360 = fuselage will notice it in this picture:
http://www.n54sg.com/images/tuft_test_04.jpg
I'm working on a write up for my website detailing the project and= its purpose and will have that posted sometime soon.  But, I will rep= ort that this did change the downwash on my horiztonal and did change my re= quired angle of incidence. Hence, I'm glad I waited to change that.  I= t actually requires less up elevator than it did before so less negative in= cidence.  The general theory is I have corrected some flow around the = fuselage thus making the entire horizontal a bit more effective.  Some= modified Legacys experienced something similar.  I only wish it would have corrected it more!  I now know more about this mod and may= be would have applied it differently.  Just not sure I'm willing to do= the work again for unknown gains.

The other aerodynamic change I = made (that relates to the original stability post) is I removed the cusp fr= om the bottom surface of my flaps as suggested in a book about GA airfoils = by Harry Riblett.  Below is a simplified version of his drawing.  = ;(Not accurate, just for explanation purposes)  The solid black is the= modification.
http://www.n54sg.com/images/Flap_Drawing.jpg
So= , what I have done to the camber of the wing is a bit odd I suppose, but it= was odd to start with.  Keep in mind, the 320 / 360 ailerons already = have this modification.  I didn't get the 10 kts I thought I would. &n= bsp;(Aren't all mods worth 10 kts? haha)  But, it is a different airfo= il.  Stall was no different, but the pitch force did increase with fla= ps extended.  Not a bad thing in my opinion.  Overall it is hard = to explain, it is a different wing, just can't pinpoint how. 

In the end I think I have made the airplane aerodynamically better, = but I have moved the problem.  It seems with just a little bit cleaner= airplane I ran in to the limit of the propeller.  Previously more rpm= always netted more speed.  Now the top 250ish rpm doesn't do much at = all.  Total bummer!  Having to learn a lot more about propellers = than I ever thought I would now...

Results of my airplane at Reno = this year:
Qualifying: 268.272 mph
Sport Medallion: 1st 261.906 mph (only 2600 rpm!)=
Heat 1C: 3r= d 268.300 mph
= Heat 2C: 2nd 265.030 mph
Heat 3C: 2nd 266.717 mph
Bronze Race: 2nd 266..944 mph

I have some really cool video from my helmet/dash cameras,= just trying to get it all edited.  Hear is a teaser of some VERY clos= e racing with Dave Morss in his Legacy: http://youtu.be/iegd6ylVHI4
Best = to watch in full screen in HD.  Keep in mind, objects in a wide angle = lens are closer than they appear! haha

Tom McNerney
www.N54= SG.com 

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