X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 23 Nov 2011 22:05:32 -0500 Message-ID: X-Original-Return-Path: Received: from nm28-vm0.bullet.mail.bf1.yahoo.com ([98.139.213.149] verified) by logan.com (CommuniGate Pro SMTP 5.4.2) with SMTP id 5211101 for lml@lancaironline.net; Tue, 22 Nov 2011 23:25:50 -0500 Received-SPF: none receiver=logan.com; client-ip=98.139.213.149; envelope-from=chris_zavatson@yahoo.com Received: from [98.139.212.145] by nm28.bullet.mail.bf1.yahoo.com with NNFMP; 23 Nov 2011 04:25:15 -0000 Received: from [98.139.212.239] by tm2.bullet.mail.bf1.yahoo.com with NNFMP; 23 Nov 2011 04:25:15 -0000 Received: from [127.0.0.1] by omp1048.mail.bf1.yahoo.com with NNFMP; 23 Nov 2011 04:25:15 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 608591.51845.bm@omp1048.mail.bf1.yahoo.com Received: (qmail 24449 invoked by uid 60001); 23 Nov 2011 04:25:15 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=X-YMail-OSG:Received:X-Mailer:References:Message-ID:Date:From:Reply-To:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=J+OI3qfGdhe/kVik4iR+tDY3Q+fUBVyXN94OdcjOj4b3N5Yg/qHVdcAzyvembqbyGamtE6LHA87m3d4TvPCqq0HB9RS4Nc3zsb2tMkTunDZ335b+691BOtmzIxA7MhgNriTlX4xO6taW812G8FqVratTZB3fWFLGJjbhDHlJYS0=; X-YMail-OSG: fr9I6MsVM1nIQtqkHT3bT7rY0Strbq8OAuhtS6UTkyky5DP X9yYBAYhZ3hitfYR5tfu.XSUIp8pLi8i7EJPA08V4iGo9gZGbr.fjLl78lZP dw.Q1wxBbzgwUFXUQuBR2COV__ZYdyq0N61MhA8MmADeHwHqZ3lvkp_Vgdpg GGKpT2U0XzuLACtA.3VoWdSQy2EOr1S4ovMOWPxAb1MZpaK7QO56ZMRtt1nC 5BkjhBE09DYFrOrO9DrEgtrXKpternQgWOoiRZ0zQo4.Wv_CPxWw4vlE5qHW 4qq_4MVKE30EBpRBGSxZYdZ1MalUDMZMB_4UQs8Ajxt2su9dBOJtBkPod_7c Z.OFTyjknIuz7p9Oiyb.mIZRPG8rnNh.SEGtJ0.T0xY_nvQxzflqh7Av_ojE 12LHftIvW4W58cDUVUt2Uxg67jt6X4YfcSueXJkGJsDWrUdHxMeMOcJoCCqN GgRq.bZLKJtxVxuKpqtHL37_DlA9SlgFCDDtvxk8NzF.qyxnZVtowcMNplhM VNMnALR_4TgErw2wqKsyHytsCV4FuNMjuzgUOySMeaaxhAGmdAxgLzTFdEuu 5xm4kmywu26mY5jw03pONKIULHk3xsbJch.wQbJWT82.78eeUvKMkezJ_Qhk lnHlGroPsmUwWjoKEj_iQBFV1EbtnAFKEKr8Pj8vTJNsYNoEfzo4_d9qdiLB ooQ-- Received: from [99.137.192.233] by web36906.mail.mud.yahoo.com via HTTP; Tue, 22 Nov 2011 20:25:14 PST X-Mailer: YahooMailWebService/0.8.115.325013 References: X-Original-Message-ID: <1322022314.23076.YahooMailNeo@web36906.mail.mud.yahoo.com> X-Original-Date: Tue, 22 Nov 2011 20:25:14 -0800 (PST) From: Chris Zavatson Reply-To: Chris Zavatson Subject: Re: [LML] Re: Legacy vibrations resolved X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="-2114655128-1446200615-1322022314=:23076" ---2114655128-1446200615-1322022314=:23076 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable The elevator trim tab is perhaps the most neglected control surface that ca= n really ruin your day.=C2=A0 The goal for us should be to remove all play = from the trim tab system.=C2=A0 There are many ADs and service bulletins wr= itten against certified planes specifying the acceptable limits.=C2=A0 We d= on't have the luxury of such a guidance and thus only find the limits throu= gh experiences conveyed by others that have=C2=A0stumbled across=C2=A0the e= dge.=C2=A0 Unfortunately the inherent play in Carbinge is similar to that o= f stock MS hinge material and will not improve the situation described in S= teve's post.=C2=A0 =0AI think Randy's post is=C2=A0also referring to the sp= herical bearings used in the tail of the 320/360 MkII=C2=A0and the Legacy i= n addition to the trim tab hinge (Randy, correct me if I am wrong).=C2=A0 T= he spherical bearing can be upgraded to=C2=A0some made to tighter tolerance= s and with better alloys.=0A=C2=A0=0AChris Zavatson=0AN91CZ=0A360std=0Awww.= N91CZ.net=C2=A0 =0A=0AFrom: John Barrett =0ATo: lml@= lancaironline.net =0ASent: Tuesday, November 22, 2011 4:53 AM=0ASubject: [L= ML] Re: Legacy vibrations resolved=0A=0A=0ACARBINGE=0A=C2=A0=0AFWIW=C2=A0 i= t=E2=80=99s worth a lot.=0A=C2=A0=0Awww.carbinge.com=0A=C2=A0=0A=C2=A0=0AFr= om:Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of randy s= narr=0ASent: Monday, November 21, 2011 5:29 AM=0ATo: lml@lancaironline.net= =0ASubject: [LML] Re: Legacy vibrations resolved=0A=C2=A0=0ASteve,=0AAs a s= ide note, I had a legacy driver stop by my hangar a few years ago. When he = shut down, there was a definite metal on metal rattle in the tail as the bl= ades came to a stop. I started inspecting the back of his plane before he g= ot out. He had the same play in the hinges. Especially the outer hinge pilo= t side.=0AWith the airplane idling, the hinges rattled pretty bad but with = the engine running you could not hear it but it was defintely there at shut= down. The tell tale gray trails were there as well. =0A=C2=A0=0AFWIW..=0AR= andy.=0A=C2=A0=0A"Flight by machines heavier than air is unpractical and in= significant, if not utterly impossible"=0A-Simon Newcomb, 1902=0AFrom:Steve= Colwell =0ATo: lml@lancaironline.net =0ASent: Sunday= , November 20, 2011 7:48 AM=0ASubject: [LML] Legacy vibrations resolved=0AO= ur Legacy has had a pitch vibration in the stick that comes and goes.=C2=A0= It seems to be related to about 50% fuel load or less and reduced but stab= le power.=C2=A0 The plane has about 275 hours and this has been going on si= nce the first 40 hours.=C2=A0 When it is vibrating in level flight (approxi= mately 2 cycles per second and the stick is visibly moving in a pronounced = shake) it will continue to vibrate when pitched up at about 1.5 G.=C2=A0 Af= ter the pitch up, when pitched down to less than 1 G, the vibration will qu= it.=C2=A0=C2=A0 After working thru many of the same contact points firewall= forward and the gear doors Paul Miller had, I still had the vibration. All= the while, I'm thinking, this is a great way to initiate flutter.=C2=A0 I = might add, I very carefully rebalanced the control surfaces after painting.= =0A=C2=A0=0AI mentioned the problem to Chris Zavatson at the Lancair Break= fast Fly-In at Willows, CA..=C2=A0 Chris asked if I had checked the control= and trim hinges for play.=C2=A0 That was easy, I check them every pre-flig= ht.=C2=A0 Only not the way Chris checks them. He pushes and pulls looking a= t the hinge.=C2=A0 See video=C2=A0 http://www.n91cz.com/HingePlay/hinges.ht= m =0A=C2=A0=0AI replaced the Pitch Trim Hinge Pin with Stainless Steel (3/3= 2=E2=80=9D - .09375) welding wire.=C2=A0 Now, no play can be seen in the pu= sh pull test.=C2=A0 We have put 20+ hours on with the new SS hinge pin and = no more stick shake.=C2=A0 I included Paul=E2=80=99s post of problem areas = (see below) since I had some of them too. =C2=A0=0A=C2=A0=0ASteve Colwell= =C2=A0 Legacy RG 310 hours=0A=C2=A0=0A=0ASent: Monday, April 12, 2010 6:47 = AM=0ATo: lml@lancaironline.net=0ASubject: [LML] Legacy vibrations resolved= =0A=C2=A0=0AI had written about vibrations in the 300 hour Legacy engine = =0Acompartment.=C2=A0 Many wrote about their fixes.=C2=A0=C2=A0 I am happy = to report that =0Athe following worked for me:=0A=C2=A0=0A1) Changed engine= isolators last year (no difference)=0A2) enlarged cutout on nose gear door= stiffener.=C2=A0 After repeatedly seeing new witness marks I did a retract= ion test and saw the interference is much larger than I expected.=C2=A0 I t= rimmed another 1/8 inch from the cutout.=C2=A0 This cutout prevents interfe= rence from the bolt attaching the linkage to the nose gear on both sides.= =C2=A0 The co-pilot side needed a larger cutout.=C2=A0 White primer was use= d to show the marks after each flight.=C2=A0 I think this was transmitting = a lot of cowl vibration.=0A3) I sprayed white primer on the areas contactin= g the baffling.=C2=A0=C2=A0 I =0Afound three hard hit areas and this is usi= ng the factory white powder coated baffling.=C2=A0 Two areas at the front o= f the #5 cylinder needed bending away from the cowl.=C2=A0 Another area jus= t above the oil cooler on the top side of the cowl was hitting.=C2=A0 The #= 5 EGT probe was hitting.=C2=A0 =0AThe #5 forward rocker cover was hitting o= n the bottom and was peened about a 1/4 to match the form of the cowl.=C2= =A0 I removed the rocker cover to check for clearance with the rocker arm.= =0A4) Baffling repairs were made to areas that were not tight against the = =0Acowl.=C2=A0=C2=A0 This significantly reduced the CHTs.=C2=A0 I used the = cooling and =0Adrag reduction data on lml from owners to help make small bu= t helpful changes in the baffling.=0A5) The prop governor cable was a hard = hit on the metal baffling and was trimmed.=0A6) The nose gear doors had a s= light overlap which was trimmed so they close tight with no gaps.=0A7) Both= main gear inner and outer doors were adjusted to be flush and tight when r= etracted.=C2=A0 This took a significant amount of time involving small hing= e adjustments and testing of each individual attachment link on the outer d= oors to get the right length before attaching both links for the final test= .=C2=A0 I say this because the two links are slightly different in length a= nd geometry.=C2=A0 I found one was a little longer than required and actual= ly twisted the door slightly open when both links were attached.=C2=A0 This= was not evident until I retracted the gear using only single links.=0A8) t= he large circular baffle behind the prop is cracked in two places and remai= ns that way until a fix can be made.=C2=A0 This appears to be from a tight = fit and needs to be measured for a new smaller piece.=C2=A0 This is a large= crack that could easily be flopping around in flight and somehow interferi= ng with the cooling process.=0A9) removed the quick drain for oil and repla= ced with the factory plug.=C2=A0 =0AI have lots of clearance and may put th= e quick drain back in.=0A=C2=A0=0AThe net result is now I have a smooth eng= ine compartment.=C2=A0=C2=A0 My symptoms =0Aincluded a difficult propeller = balancing as we could never exactly home in on a solution.=C2=A0 The vibrat= ion was small at 2700 rpm and takeoff but increased significantly with rpm = reduction.=C2=A0 I attribute that to the higher torque twisting the engine = closer to the left side of the baffling.=C2=A0 The vibration was evident in= the cockpit, cowling and when looking at the wings.=C2=A0 The next project= will be to replace the silicone baffle with new material and replace the c= ircular baffle plate behind the prop and replace the left side metal baffle= to better fit the cowl line near the #5 cylinder.=C2=A0 Many thanks to all= the suggestions that made this easier to do.=0A=C2=A0=0APaul Miller=0AN357= V Legacy RG ---2114655128-1446200615-1322022314=:23076 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
The elevator trim tab is perhaps the most neglected = control surface that can really ruin your day.  The goal for us should= be to remove all play from the trim tab system.  There are man= y ADs and service bulletins written against certified planes specifying the acceptable= limits.  We don't have the luxury of such a guidance and thus only fi= nd the limits through experiences conveyed by others that have stumble= d across the edge.  Unfortunately the inherent play in Carbinge i= s similar to that of stock MS hinge material and will not improve the situa= tion described in Steve's post. 
I think Randy's post is also referring to the spherical bearings used = in the tail of the 320/360 MkII and the Legacy in addition to the trim= tab hinge (Randy, correct me if I am wrong).  The spherical bearing c= an be upgraded to some made to tighter tolerances and with better allo= ys.
 
Chris Zavatson
N91CZ
360std

From:= John Barrett <jbarrett@carbinge.com>
To: lml@lancaironline.net
Sent: Tuesday, November 22, 2011 4:53 AM<= BR>Subject: [LML] Re: Legac= y vibrations resolved

From: Lancair Mailing List [mailto:lml@lancaironline.net]= On Behalf Of randy snarr
Sent: Monday, November 21, 2011 = 5:29 AM
To: lml@lancaironline.net
Subject: [LML] Re: Le= gacy vibrations resolved
 
Steve,
As a side note, I had a legacy driver stop by my hangar a= few years ago. When he shut down, there was a definite metal on metal ratt= le in the tail as the blades came to a stop. I started inspecting the back = of his plane before he got out. He had the same play in the hinges. Especia= lly the outer hinge pilot side.
With the airplane idling, the hinges rat= tled pretty bad but with the engine running you could not hear it but it wa= s defintely there at shut down. The tell tale gray trails were there as wel= l.
 
FWIW..
Randy.
 
"Flight by machines heavier than air is unpractical an= d insignificant, if not utterly impossible"
-Simon Newcomb, 1902
From: Steve Colwell <mcmess1919@yahoo.com>
= To: lml@lancaironline.net
Sent: Sunday, November 20, 2011 7:= 48 AM
Subject: [LML] Legacy vibrations resolved
Our Legacy has had a pitch vibration in the stick that co= mes and goes.  It seems to be related to about 50% fuel load or less a= nd reduced but stable power.  The plane has about 275 hours and this h= as been going on since the first 40 hours.  When it is vibrating in le= vel flight (approximately 2 cycles per second and the stick is visibly movi= ng in a pronounced shake) it will continue to vibrate when pitched up at ab= out 1.5 G.  After the pitch up, when pitched down to less than 1 G, th= e vibration will quit.   After working thru many of the same cont= act points firewall forward and the gear doors Paul Miller had, I still had= the vibration. All the while, I'm thinking, this is a great way to initiat= e flutter.  I might add, I very carefully rebalanced the control surfa= ces after painting.
 
I mentioned the problem to Chris Zavatson at the Lancair = Breakfast Fly-In at Willows, CA..  Chris asked if I had checked the co= ntrol and trim hinges for play.  That was easy, I check them every pre= -flight.  Only not the way Chris checks them. He pushes and pulls look= ing at the hinge.  See video  http://www.n91cz.com/HingePlay/hing= es.htm
 
I replaced the Pitch Trim Hinge Pin with Stainless Steel = (3/32=E2=80=9D - .09375) welding wire.  Now, no play can be seen in th= e push pull test.  We have put 20+ hours on with the new SS hinge pin = and no more stick shake.  I included Paul=E2=80=99s post of problem ar= eas (see below) since I had some of them too.  
 
Steve Colwell  Legacy RG 310 hours
 

Sent: Monday, April 12, 2010 6:47 AM
To: lml@lanca= ironline.net
Subject: [LML] Legacy vibrations resolved
 
I had written about vibrations in the 300 hour Legacy eng= ine
compartment.  Many wrote about their fixes. &nb= sp; I am happy to report that
the following worked for me:
 
1) Changed engine isolators last year (no difference)
2) enlarged cutout on nose gear door stiffener.  Aft= er repeatedly seeing new witness marks I did a retraction test and saw the = interference is much larger than I expected.  I trimmed another 1/8 in= ch from the cutout.  This cutout prevents interference from the bolt a= ttaching the linkage to the nose gear on both sides.  The co-pilot sid= e needed a larger cutout.  White primer was used to show the marks aft= er each flight.  I think this was transmitting a lot of cowl vibration= .
3) I sprayed white primer on the areas contacting the baf= fling.   I
found three hard hit areas and this is using the factory = white powder coated baffling.  Two areas at the front of the #5 cylind= er needed bending away from the cowl.  Another area just above the oil= cooler on the top side of the cowl was hitting.  The #5 EGT probe was= hitting. 
The #5 forward rocker cover was hitting on the bottom and= was peened about a 1/4 to match the form of the cowl.  I removed the = rocker cover to check for clearance with the rocker arm.
4) Baffling repairs were made to areas that were not tigh= t against the
cowl.   This significantly reduced the CHTs.&nb= sp; I used the cooling and
drag reduction data on lml from owners to help make small= but helpful changes in the baffling.
5) The prop governor cable was a hard hit on the metal ba= ffling and was trimmed.
6) The nose gear doors had a slight overlap which was tri= mmed so they close tight with no gaps.
7) Both main gear inner and outer doors were adjusted to = be flush and tight when retracted.  This took a significant amount of = time involving small hinge adjustments and testing of each individual attac= hment link on the outer doors to get the right length before attaching both= links for the final test.  I say this because the two links are sligh= tly different in length and geometry.  I found one was a little longer= than required and actually twisted the door slightly open when both links = were attached.  This was not evident until I retracted the gear using = only single links.
8) the large circular baffle behind the prop is cracked i= n two places and remains that way until a fix can be made.  This appea= rs to be from a tight fit and needs to be measured for a new smaller piece.=   This is a large crack that could easily be flopping around in flight= and somehow interfering with the cooling process.
9) removed the quick drain for oil and replaced with the = factory plug. 
I have lots of clearance and may put the quick drain back= in.
 
The net result is now I have a smooth engine compartment.=    My symptoms
included a difficult propeller balancing as we could neve= r exactly home in on a solution.  The vibration was small at 2700 rpm = and takeoff but increased significantly with rpm reduction.  I attribu= te that to the higher torque twisting the engine closer to the left side of= the baffling.  The vibration was evident in the cockpit, cowling and = when looking at the wings.  The next project will be to replace the si= licone baffle with new material and replace the circular baffle plate behin= d the prop and replace the left side metal baffle to better fit the cowl li= ne near the #5 cylinder.  Many thanks to all the suggestions that made= this easier to do.
 
Paul Miller
N357V Legacy RG
 


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