X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 08 Oct 2013 07:55:04 -0400 Message-ID: X-Original-Return-Path: Received: from nm27-vm1.bullet.mail.bf1.yahoo.com ([98.139.213.148] verified) by logan.com (CommuniGate Pro SMTP 6.0.7) with ESMTPS id 6506014 for lml@lancaironline.net; Mon, 07 Oct 2013 18:08:24 -0400 Received-SPF: none receiver=logan.com; client-ip=98.139.213.148; envelope-from=chris_zavatson@yahoo.com Received: from [66.196.81.170] by nm27.bullet.mail.bf1.yahoo.com with NNFMP; 07 Oct 2013 22:07:51 -0000 Received: from [98.139.212.238] by tm16.bullet.mail.bf1.yahoo.com with NNFMP; 07 Oct 2013 18:50:37 -0000 Received: from [127.0.0.1] by omp1047.mail.bf1.yahoo.com with NNFMP; 07 Oct 2013 18:05:28 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 803767.25684.bm@omp1047.mail.bf1.yahoo.com Received: (qmail 96582 invoked by uid 60001); 7 Oct 2013 18:05:28 -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:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=5BBjwJH9/HzOKozs35gxlcsBlPHWr1gpzPv2p2Mv/yZWtwZC6sA5VDMarmpNb0FK9VC66xlEcUs/C7T5+DyL8D/vOK7QxpjkmmeHbGuUxFDM3aWG+8AWgKoyWHJnB/pFOE1GH/HI8rlgNkBmz1x3/vb6THUSwinMb1l+I9ld3lk=; X-YMail-OSG: tjStLDkVM1m3GAHWGZ7dZ3b2zgBziPhsegDRPK9B_WNJtb9 2fh1dsbkkEy1M8r_OQzbLHa6jWFGi7gs8v8DpdJXNkJiaj.BEemSGAV.UMFL 99HSL87Qpj7NqPTyh2QADshfOWFw2HtB2CclO.UN9MNa9meIpAdmNvXwLIU6 S3O0DYvzuw.0OYFn1x10C7JrPd0z0jWQg9XOMuvaiZDAbESky7Bzc6D7qRmT .2XegXuhIK6glDON7i1IfXr0VxIij.4E1gfRLjVX6fEEvTvMQ9CSeGHXlBBY q1gE_Op9F4jOM1bx9dlEhqDUutDrwSa6oilFOQQTwhf6C5pvMXn3Gu69DZlb LPDWQT5Ibm3v7By77UfEKs_mvO6mJkXou.PySyA.xoTPJV3GxeC1UJKTQudm X6mJ8vrQFPu42ZvtU3QftPfSLcsUriSVI_RS9_O.EFyp6akWf135OJklGPQd 1Q6b0HFcD4H7ri3D_su.w2oR0tLTp2a7LL7EEruidGGsLM__Ruus0m2_Daoa Ux9nHiQ2yIHxfszJuFM5Cva7wTnPH3afkT3AEbjVOyeh_3QPoy_yqIP60GO3 A_7jHm6rT9i22AswokpqFbn1D7TAbeWunYmziZFKAjFmPfOuh2IFfee2b1g5 qdGrq7spmlszf_12al69oYWaWVfk6sgVLZe7yk1b3yH2GmrKmNkN6D4Q8aop ep4VG1CdnIqjrbQllmXxQV06B6ct0zq5wkwWrIHZxIphc502Z75XswEFCzAY QLTTPU0mqUcmnaBvPAKmMarT0RrvE8xFCnU4EDVgXf_EbBAtpUCu8AEDJUSI TDzGgjceGOjbvflVOBjDS Received: from [172.14.16.72] by web121604.mail.ne1.yahoo.com via HTTP; Mon, 07 Oct 2013 11:05:27 PDT X-Rocket-MIMEInfo: 002.001,Q3JhaWcsCiJJwqB3YXMgdGhpbmtpbmcgYWJvdXQgcmVkdWNpbmcgZW5naW5lIGRvd250aHJ1c3QuwqAgQW55IHRob3VnaHRzIG9uIHRoaXMgQ2hyaXM_IgrCoApMZXNzIGRvd250aHJ1c3QgaXMgZGVzdGFiaWxpemluZy7CoCAKSWYgeW91IGFyZSBnb2luZyB0byBjaGFuZ2UgZG93bnRocnVzdCwgSSB3b3VsZMKgbG92ZSB0byByZWNvcmQgeW91ciBuZXV0cmFsIHBvaW50IGJlZm9yZSBhbmQgYWZ0ZXIuwqAgSXQgaXMgcmFyZSB0byBnZXQgc3RhYmlsaXR5IGRhdGEgb24gYSBwcm9wZWxsZXIgY2hhbmdlcyBsaWsBMAEBAQE- X-Mailer: YahooMailWebService/0.8.160.587 References: X-Original-Message-ID: <1381169127.66906.YahooMailNeo@web121604.mail.ne1.yahoo.com> X-Original-Date: Mon, 7 Oct 2013 11:05:27 -0700 (PDT) From: Chris Zavatson Reply-To: Chris Zavatson Subject: Re: [LML] 320/360 performance and stability X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-36511695-713916033-1381169127=:66906" ---36511695-713916033-1381169127=:66906 Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable Craig,=0A"I=A0was thinking about reducing engine downthrust.=A0 Any thought= s on this Chris?"=0A=A0=0ALess downthrust is destabilizing.=A0 =0AIf you ar= e going to change downthrust, I would=A0love to record your neutral point b= efore and after.=A0 It is rare to get stability data on a propeller changes= like this.=0A=A0=0AHere is paper that discusses the stability changes to t= he Hawkeye E-2C simply by increasing prop disc solidity.=A0 Four blade to e= ight blade prop.=0A=A0http://n91cz.com/Interesting_Technical_Reports/E2_pro= p_change.pdf=0AChris Zavatson=0AN91CZ=0A360std=0Ahttp://www.n91cz.net/ =0A= =A0 =0AFrom:Craig Schulze=0A[mailto:craig@skybolt.net] =0ASent: Thursday, O= ctober 03, 2013 1:04 PM=0ATo: 'dudewanarace@yahoo.com'=0ASubject: RE: 320/3= 60 performance and stability =0A=A0 =0AHi Tom, =0A=A0 =0AWhat type of odd= experiences are you having with yours?=A0 I=0Ahave been noticing that the = faster I go the more pitch sensitive it is. I=0A=A0have the small tail too = and my elevator position is about the same as=0Ayours in cruise.=A0 I was t= hinking about reducing engine downthrust.=A0=0AAny thoughts on this Chris? = =0A=A0 =0AWhat were the results of flattening the bottom of the=0Aflaps?=A0= Any speed gain? =0A=A0 =0ACraig =0ASmall tail 360 N73S =0A=A0 =0A=A0 =0AFr= om:dudewanarace@yahoo.com [mailto:dudewanarace@yahoo.com] =0ASent: Wednesda= y, October 02, 2013 4:50 AM=0ATo: lml@lancaironline.net=0ASubject: 320/360 = performance and stability =0A=A0 =0AReaders, =0AI have been watching thi= s conversation with interest. =A0I have=0Asome odd experiences with stabili= ty in my small tail 360 that was improperly built=0A(not by me). =A0Geez, t= hat is going to hurt resale.. haha =0A=A0 =0AAnyway,=0AI have been waitin= g to comment as it will just fog the data that has been=0Apresented given m= y totally odd arrangement and lack of any real data. =A0All=0Aof my 'data' = is seat of the pants, thus not worth mentioning. =A0But,=0Afigured I could = expand on an envelope probably few have visited just for=0Ainteresting read= ing. =0A=A0 =0AThis=0Ais my elevator angle with the airplane in a forward= C.G. condition (header fuel=0Aonly, single pilot), flaps in reflex and, we= ll, going as fast as an RV-7 will=0Ago in formation. :) =0Ahttp://www.n54s= g.com/images/tuft_test_08.jpg =0A=A0 =0ASo,=0Athis problem poses a few is= sues. =0AFirst,=0Athis is obviously drag, probably a measurable amount thu= s for me the driving=0Aforce behind correcting it one day. =A0Second is the= available elevator=0Atravel. =A0If you read the manual, I have the correct= amount of up / down=0Aelevator travel. =A0But, if the photo is my starting= point, it means I have=0Amuch less up, and way too much down available to = use. =A0The important part=0Abeing the elevator up while in the flare. =A0G= iven a forward C.G. and a huge=0Aamount of flaps, this can be an issue. (as= k me how I know...) =0A=A0 =0ANext=0AI would like to mention that not all= small tails trim the same. =A0Some use=0Aa spring system to bias the entir= e elevator. =A0Others use trim tabs.=0A=A0I have a tab that due to its plac= ement and odd elevator deflection has a=0Alimited functional envelope. =A0A= nother driving force to change incidence. =0A=A0 =0ANow=0Athe often obvio= us question people ask is why haven't I fixed it yet. =A0Well,=0Abecause th= e job of fixing it is going to totally suck, and I wanted it to be=0Athe la= st thing I do as my other aerodynamic changes may affect the angle of=0Ainc= idence. =A0This brings me to the next subject, what I have changed. =0A=A0= =0ASo=0AI have this airplane going faster than most and figured why stop = now.. I made a=0Arather drastic change that some call the beluga belly. =A0= It has been done=0Ato a few Legacys that race with varied applications of t= he same idea.=0A=A0Those familiar with the 320/360 fuselage will notice it = in this picture: =0Ahttp://www.n54sg.com/images/tuft_test_04.jpg =0AI'm= =0Aworking on a write up for my website detailing the project and its purpo= se and=0Awill have that posted sometime soon. =A0But, I will report that th= is did=0Achange the downwash on my horiztonal and did change my required an= gle of=0Aincidence. Hence, I'm glad I waited to change that. =A0It actually= requires=0Aless up elevator than it did before so less negative incidence.= =A0The=0Ageneral theory is I have corrected some flow around the fuselage = thus making=0Athe entire horizontal a bit more effective. =A0Some modified = Legacys=0Aexperienced something similar. =A0I only wish it would have corre= cted it=0Amore! =A0I now know more about this mod and maybe would have appl= ied it=0Adifferently. =A0Just not sure I'm willing to do the work again for= unknown=0Agains. =0A=A0 =0AThe=0Aother aerodynamic change I made (that r= elates to the original stability post)=0Ais I removed the cusp from the bot= tom surface of my flaps as suggested in a=0Abook about GA airfoils by Harry= Riblett. =A0Below is a simplified version of=0Ahis drawing. =A0(Not accura= te, just for explanation purposes) =A0The=0Asolid black is the modification= . =0Ahttp://www.n54sg.com/images/Flap_Drawing.jpg =0ASo,=0Awhat I have do= ne to the camber of the wing is a bit odd I suppose, but it was=0Aodd to st= art with. =A0Keep in mind, the 320 / 360 ailerons already have this=0Amodif= ication. =A0I didn't get the 10 kts I thought I would. =A0(Aren't=0Aall mod= s worth 10 kts? haha) =A0But, it is a different airfoil. =A0Stall=0Awas no = different, but the pitch force did increase with flaps extended.=0A=A0Not a= bad thing in my opinion. =A0Overall it is hard to explain, it is=0Aa diffe= rent wing, just can't pinpoint how.=A0 =0A=A0 =0AIn=0Athe end I think I h= ave made the airplane aerodynamically better, but I have=0Amoved the proble= m. =A0It seems with just a little bit cleaner airplane I ran=0Ain to the li= mit of the propeller. =A0Previously more rpm always netted more=0Aspeed. = =A0Now the top 250ish rpm doesn't do much at all. =A0Total bummer!=0A=A0Hav= ing to learn a lot more about propellers than I ever thought I would now...= =0A=A0 =0AResults=0Aof 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=A0 =0AI=0Ahave some really cool video from m= y helmet/dash cameras, just trying to get it=0Aall edited. =A0Hear is a tea= ser of some VERY close racing with Dave Morss in=0Ahis Legacy: http://youtu= .be/iegd6ylVHI4 =0ABest=0Ato watch in full screen in HD. =A0Keep in mind, = objects in a wide angle lens=0Aare closer than they appear! haha =0A=A0 = =0ATom=0AMcNerney =0Awww.N54SG.com=A0 ---36511695-713916033-1381169127=:66906 Content-Type: text/html; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable
<= div style=3D"color: rgb(0, 0, 0); font-family: arial, helvetica, sans-serif= ; font-size: 12pt; background-color: rgb(255, 255, 255);">
Craig,
"I was thinking about reducing engine downthrust.  A= ny thoughts on this Chris?"
 
Less downthrust is dest= abilizing. 
If you are going to change downthrust, I would = love to record your neutral point before and after.  It is rare to get= stability data on a propeller changes like=0A this.
 
=
Here is paper that disc= usses the stability changes to the Hawkeye E-2C simply by increasing prop d= isc solidity.  Four blade to eight blade prop.
 http://n91cz.com/Interesting_Technical_Reports/E2_pr= op_change.pdf
=0A=0A=0A =0A =0A
=0A=0A=0A=0A
=0A=0A
=0A=0A
= = Chris Zavatson
N91CZ
360std
http://www.= n91cz.net/
=0A=0A
&n= bsp;
=0A=0A
=0A=0A
=0A=0A
From:<= span class=3D"yiv1246827791ms__id3962"> Craig Schulze=0A[mailto:craig@skybo= lt.net]
=0ASent: Thursday, October 03, 2013 1:04 = PM
=0ATo: 'dudewanarace@yahoo.com'
=0ASubject: RE: 320/360 performance and stability
= =0A=0A
=0A=0A
=0A=0A
 =
=0A=0A
Hi Tom,
=0A= =0A
 
=0A=0A
What type of odd experiences are you having with yours?  I=0Ah= ave been noticing that the faster I go the more pitch sensitive it is. I=0A=  have the small tail too and my elevator position is about the same as= =0Ayours in cruise.  I was thinking about reducing engine downthrust.&= nbsp;=0AAny thoughts on this Chris?
=0A=0A
 
=0A=0A
What were the results of flattening the bottom of the=0Aflaps? = ; Any speed gain?
=0A=0A
= =  
=0A=0A
Craig
=0A=0A
Small tail 360 N73S
=0A=0A
 
= =0A=0A
 
=0A=0A=0A=0A
=0A=0A
From:=0Adudewanarace@yahoo.com [mailto:dudewanarace@yahoo.com]
=0ASent: Wednesday, October 02, 2013 4:50 AM
=0ATo: lml@lancaironline.net
=0ASubje= ct: 320/360 performance and stability
=0A=0A
=0A=0A=0A=0A
 
=0A=0A
= =0A=0A
=0A=0A
Re= aders,
=0A=0A
=0A=0A
=0A=0A
I have been watching this conversation with i= nterest.  I have=0Asome odd experiences with stability in my small tai= l 360 that was improperly built=0A(not by me).  Geez, that is going to= hurt resale.. haha
=0A=0A
=0A=0A
=0A=0A
 
=0A=0A=0A=0A
=0A=0A
Anyway,=0AI have been waiting = to comment as it will just fog the data that has been=0Apresented given my = totally odd arrangement and lack of any real data.  All=0Aof my 'data'= is seat of the pants, thus not worth mentioning.  But,=0Afigured I co= uld expand on an envelope probably few have visited just for=0Ainteresting = reading.
=0A=0A
=0A=0A
=0A=0A
 
=0A=0A
=0A=0A
=0A=0A
This=0Ais my elevator angle with the airplane in a forward C.G. condit= ion (header fuel=0Aonly, single pilot), flaps in reflex and, well, going as= fast as an RV-7 will=0Ago in formation. :)
=0A=0A
=0A=0A=
=0A=0A
http://www.n54sg.com/images/tuft_test= _08.jpg
=0A=0A
=0A=0A
=0A=0A
 
=0A=0A=0A=0A
=0A=0A
So,=0Athis problem poses a few= issues.
=0A=0A
=0A=0A
=0A=0A
First,=0Athis is obviously drag, probably a measurable amount thus for m= e the driving=0Aforce behind correcting it one day.  Second is the ava= ilable elevator=0Atravel.  If you read the manual, I have the correct = amount of up / down=0Aelevator travel.  But, if the photo is my starti= ng point, it means I have=0Amuch less up, and way too much down available t= o use.  The important part=0Abeing the elevator up while in the flare.=  Given a forward C.G. and a huge=0Aamount of flaps, this can be an is= sue. (ask me how I know...)
=0A=0A
=0A=0A
=0A=0A
 
=0A=0A
=0A=0A
=0A=0ANext=0AI would like to mention that not all small t= ails trim the same.  Some use=0Aa spring system to bias the entire ele= vator.  Others use trim tabs.=0A I have a tab that due to its pla= cement and odd elevator deflection has a=0Alimited functional envelope. &nb= sp;Another driving force to change incidence.
=0A=0A
=0A= =0A
=0A=0A
 
=0A=0A
= =0A=0A
=0A=0A
Now=0Athe often obvious questio= n people ask is why haven't I fixed it yet.  Well,=0Abecause the job o= f fixing it is going to totally suck, and I wanted it to be=0Athe last thin= g I do as my other aerodynamic changes may affect the angle of=0Aincidence.=  This brings me to the next subject, what I have changed. =0A=0A
=0A=0A
=0A=0A
  =0A=0A
=0A=0A
=0A=0A
So=0AI have thi= s airplane going faster than most and figured why stop now.. I made a=0Arat= her drastic change that some call the beluga belly.  It has been done= =0Ato a few Legacys that race with varied applications of the same idea.=0A=  Those familiar with the 320/360 fuselage will notice it in this pictu= re:
=0A=0A
=0A=0A
=0A=0A
ht= tp://www.n54sg.com/images/tuft_test_04.jpg
=0A=0A
=0A=0A<= div>=0A=0A
I'm=0Aworking on a write up for my web= site detailing the project and its purpose and=0Awill have that posted some= time soon.  But, I will report that this did=0Achange the downwash on = my horiztonal and did change my required angle of=0Aincidence. Hence, I'm g= lad I waited to change that.  It actually requires=0Aless up elevator = than it did before so less negative incidence.  The=0Ageneral theory i= s I have corrected some flow around the fuselage thus making=0Athe entire h= orizontal a bit more effective.  Some modified Legacys=0Aexperienced s= omething similar.  I only wish it would have corrected it=0Amore! &nbs= p;I now know more about this mod and maybe would have applied it=0Adifferen= tly.  Just not sure I'm willing to do the work again for unknown=0Agai= ns.
=0A=0A
=0A=0A
=0A=0A
&= nbsp;
=0A=0A
=0A=0A
=0A=0A
= The=0Aother aerodynamic change I made (that relates to the original stabili= ty post)=0Ais I removed the cusp from the bottom surface of my flaps as sug= gested in a=0Abook about GA airfoils by Harry Riblett.  Below is a sim= plified version of=0Ahis drawing.  (Not accurate, just for explanation= purposes)  The=0Asolid black is the modification.
=0A=0A=
=0A=0A
=0A=0A
http://www.n54sg.com/imag= es/Flap_Drawing.jpg
=0A=0A
=0A=0A
=0A=0A
So,=0Awhat I have done to the camber of the wing is a bit odd= I suppose, but it was=0Aodd to start with.  Keep in mind, the 320 / 3= 60 ailerons already have this=0Amodification.  I didn't get the 10 kts= I thought I would.  (Aren't=0Aall mods worth 10 kts? haha)  But,= it is a different airfoil.  Stall=0Awas no different, but the pitch f= orce did increase with flaps extended.=0A Not a bad thing in my opinio= n.  Overall it is hard to explain, it is=0Aa different wing, just can'= t pinpoint how. 
=0A=0A
=0A=0A
=0A=0A
 
=0A=0A
=0A=0A
=0A=0A
In=0Athe end I think I have made the airplane aerodyna= mically better, but I have=0Amoved the problem.  It seems with just a = little bit cleaner airplane I ran=0Ain to the limit of the propeller.  = ;Previously more rpm always netted more=0Aspeed.  Now the top 250ish r= pm doesn't do much at all.  Total bummer!=0A Having to learn a lo= t more about propellers than I ever thought I would now...
=0A= =0A
=0A=0A
=0A=0A
 
= =0A=0A
=0A=0A
=0A=0A
Results=0Aof my air= plane at Reno this year:
=0A=0A
=0A=0A
=0A=0A
Qualifying: 268.272 mph
=0AS= port Medallion: 1st 261.906 mph (only 2600 rpm!)
=0AHeat = 1C: 3rd 268.300 mph
=0AHeat 2C: 2nd 265.030 mph
=0AHeat 3C: 2nd 266.717 mph
=0ABronze Race: 2nd= 266..944 mph
=0A=0A
=0A=0A
=0A=0A
 
=0A=0A
=0A=0A
=0A=0A
I=0Ahave some really cool video from my helmet/dash cameras, just try= ing to get it=0Aall edited.  Hear is a teaser of some VERY close racin= g with Dave Morss in=0Ahis Legacy: http://youtu.be/iegd6ylVHI4
= =0A=0A
=0A=0A
=0A=0A
Best=0Ato watch in= full screen in HD.  Keep in mind, objects in a wide angle lens=0Aare = closer than they appear! haha
=0A=0A
=0A=0A
=0A=0A  
=0A=0A
=0A=0A
=0A=0A<= div class=3D"yiv1246827791MsoNormal">Tom=0AMcNerney
=0A=0A
=0A=0A=0A=0A
www.N54SG.com 
=0A=0A<= /div>=0A=0A
=0A=0A
 
=0A= =0A
=0A=0A
=0A=0A
=0A=0A
=0A=0A


---36511695-713916033-1381169127=:66906--