X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 02 Oct 2013 13:29:53 -0400 Message-ID: X-Original-Return-Path: Received: from omr-m02.mx.aol.com ([64.12.143.76] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with ESMTPS id 6499279 for lml@lancaironline.net; Wed, 02 Oct 2013 09:57:58 -0400 Received-SPF: pass receiver=logan.com; client-ip=64.12.143.76; envelope-from=n5276j@aol.com Received: from mtaomg-da03.r1000.mx.aol.com (mtaomg-da03.r1000.mx.aol.com [172.29.51.139]) by omr-m02.mx.aol.com (Outbound Mail Relay) with ESMTP id 29FC17011D593 for ; Wed, 2 Oct 2013 09:57:24 -0400 (EDT) Received: from core-mla002c.r1000.mail.aol.com (core-mla002.r1000.mail.aol.com [172.29.186.80]) by mtaomg-da03.r1000.mx.aol.com (OMAG/Core Interface) with ESMTP id E0E74E000088 for ; Wed, 2 Oct 2013 09:57:23 -0400 (EDT) References: X-Original-To: lml@lancaironline.net Subject: Re: [LML] 320/360 performance and stability In-Reply-To: X-MB-Message-Source: WebUI MIME-Version: 1.0 From: steve X-MB-Message-Type: User Content-Type: multipart/alternative; boundary="--------MB_8D08D8E74581061_1BD4_D8389_webmail-m274.sysops.aol.com" X-Mailer: AOL Webmail 38079-STANDARD Received: from 70.193.194.144 by webmail-m274.sysops.aol.com (64.12.145.239) with HTTP (WebMailUI); Wed, 02 Oct 2013 09:57:23 -0400 X-Original-Message-Id: <8D08D8E74534DA1-1BD4-40A83@webmail-m274.sysops.aol.com> X-Originating-IP: [70.193.194.144] X-Original-Date: Wed, 2 Oct 2013 09:57:23 -0400 (EDT) x-aol-global-disposition: G x-aol-sid: 3039ac1d338b524c26437dcf This is a multi-part message in MIME format. ----------MB_8D08D8E74581061_1BD4_D8389_webmail-m274.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset="us-ascii" Hey Tom Congratulations on Reno, guess you're the 360 -400 speed man. So have you played around with the -10 degree reflex vs -7? Looked like on= e of your pics the flaps were above the flared-in position. Steve Alderman 25SA 360 -----Original Message----- From: dudewanarace To: lml Sent: Wed, Oct 2, 2013 5:50 am Subject: [LML] 320/360 performance and stability Readers, I have been watching this conversation with interest. I have some odd expe= riences 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 ha= s been presented given my totally odd arrangement and lack of any real data= . All of my 'data' is seat of the pants, thus not worth mentioning. But, = figured I could expand on an envelope probably few have visited just for in= teresting reading. This is my elevator angle with the airplane in a forward C.G. condition (he= ader fuel only, single pilot), flaps in reflex and, well, going as fast as = an RV-7 will go in formation. :) http://www.n54sg.com/images/tuft_test_08.jpg So, this problem poses a few issues. First, this is obviously drag, probably a measurable amount thus for me the= driving force behind correcting it one day. Second is the available eleva= tor travel. If you read the manual, I have the correct amount of up / down= elevator travel. But, if the photo is my starting point, it means I have = much less up, and way too much down available to use. The important part b= eing the elevator up while in the flare. Given a forward C.G. and a huge a= mount 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 system to bias the entire elevator. Others use trim tabs. I = have a tab that due to its placement and odd elevator deflection has a limi= ted functional envelope. Another driving force to change incidence. Now the often obvious question people ask is why haven't I fixed it yet. W= ell, 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 may affect the a= ngle of incidence. This brings me to the next subject, what I have changed= . So I have this airplane going faster than most 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 varied 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 purp= ose and will have that posted sometime soon. But, I will report that this = did change the downwash on my horiztonal and did change my required angle o= f incidence. Hence, I'm glad I waited to change that. It actually requires= less up elevator than it did before so less negative incidence. The gener= al 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 kn= ow more about this mod and maybe would have applied it differently. Just n= ot 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 from the bottom surface of my flaps as suggest= ed in a book about GA airfoils by Harry Riblett. Below is a simplified ver= sion of his drawing. (Not accurate, just for explanation purposes) The so= lid 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 hav= e this modification. I didn't get the 10 kts I thought I would. (Aren't a= ll mods worth 10 kts? haha) But, it is a different airfoil. Stall was no = different, but the pitch force did increase with flaps extended. Not a bad= thing in my opinion. Overall it is hard to explain, it is a different win= g, just can't pinpoint how.=20 In the end I think I have made the airplane aerodynamically better, but I h= ave 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 mo= re speed. Now the top 250ish rpm doesn't do much at all. Total bummer! H= aving 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: 3rd 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 g= et it all edited. Hear is a teaser of some VERY close racing with Dave Mor= ss 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.N54SG.com ; ----------MB_8D08D8E74581061_1BD4_D8389_webmail-m274.sysops.aol.com Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset="us-ascii"
Hey Tom
 
Congratulations on Reno, guess you're the 360 -400 speed man.3D"8-)"
 
So have you played around with the -10 degree reflex vs  -7? Look= ed like one of your pics the flaps were above the flared-in position.
 
Steve Alderman    25SA  360
-----Original Message-----
From: dudewanarace <dudewanarace@yahoo.com>
To: lml <lml@lancaironline.net>
Sent: Wed, Oct 2, 2013 5:50 am
Subject: [LML] 320/360 performance and stability

= Readers,
= I have been watching 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
=
Any= way, I have been waiting to comment as it will just fog the data that has b= een presented given my totally odd arrangement and lack of any real data. &= nbsp;All of my 'data' is seat of the pants, thus not worth mentioning. &nbs= p;But, figured I could expand on an envelope probably few have visited just for interesting= reading.
Thi= s is my elevator angle with the airplane in a forward C.G. condition (heade= r fuel only, single pilot), flaps in reflex and, well, going as fast as an = RV-7 will go in formation. :)

So, this problem poses a few issue= s.
First, this is obviously drag, pro= bably a measurable amount thus for me the driving force behind correcting i= t one day.  Second is the available elevator travel.  If you read= the manual, I have the correct amount of up / down elevator travel.  = But, if the photo is my starting point, it means I have much less up, and w= ay too much down available to use.  The important part being the eleva= tor up while in the flare.  Given 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 system to bias t= he entire elevator.  Others use trim tabs.  I have a tab that due= to its placement and odd elevator deflection has a limited functional enve= lope.  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 may affect the= angle of incidence.  This brings me to the next subject, what I have = changed.
So = I have this airplane going faster than most and figured why stop now.. I ma= de a rather drastic change that some call the beluga belly.  It has be= en done to a few Legacys that race with varied applications of the same ide= a.  Those familiar with the 320/360 fuselage will notice it in this pi= cture:
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 report that thi= s did change the downwash on my horiztonal and did change my required angle= of incidence. Hence, I'm glad I waited to change that.  It actually r= equires less up elevator than it did before so less negative incidence. &nb= sp;The general theory is I have corrected some flow around the fuselage thu= s making the entire horizontal a bit more effective.  Some modified Le= gacys 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 po= st) is I removed the cusp from the bottom surface of my flaps as suggested = in a book about GA airfoils by Harry Riblett.  Below is a simplified v= ersion of his drawing.  (Not accurate, just for explanation purposes) =  The solid black is the modification.
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 h= ave this modification.  I didn't get the 10 kts I thought I would. &nb= sp;(Aren't all mods worth 10 kts? haha)  But, it is a different airfoi= l.  Stall was no different, but the pitch force did increase with flap= s extended.  Not a bad thing in my opinion.  Overall it is hard t= o 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 ne= tted 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 eve= r thought I would now...
Res= ults of my airplane at Reno this year:
Qualifying:= 268.272 mph
Sport Medallion: 1st 261.906 mph (only 2600 rpm!)
Heat 1C: 3rd 268.300 mph
Heat 2C: 2nd 265.030 mp= h
Heat 3C: 2= nd 266.717 mph
Bronze Race: 2nd 266..944 mph
I h= ave some really cool video from my helmet/dash cameras, just trying to get = it all edited.  Hear is a teaser of some VERY close racing with Dave M= orss in his Legacy: http://youtu.be/iegd6ylVHI4
Bes= t to watch in full screen in HD.  Keep in mind, objects in a wide angl= e lens are closer than they appear! haha
Tom= McNerney
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