X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 06 Apr 2011 07:38:35 -0400 Message-ID: X-Original-Return-Path: Received: from smtp105-mob.biz.mail.ne1.yahoo.com ([98.138.88.242] verified) by logan.com (CommuniGate Pro SMTP 5.4c2) with SMTP id 4933632 for lml@lancaironline.net; Tue, 05 Apr 2011 14:56:13 -0400 Received-SPF: none receiver=logan.com; client-ip=98.138.88.242; envelope-from=chris_zavatson@yahoo.com Received: (qmail 22828 invoked from network); 5 Apr 2011 18:55:37 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=DKIM-Signature:Received:X-Yahoo-SMTP:X-YMail-OSG:X-Yahoo-Newman-Property:References:In-Reply-To:X-Apple-Yahoo-Original-Message-Folder:Mime-Version:Content-Type:Content-Transfer-Encoding:Message-Id:X-Mailer:From:X-Apple-Yahoo-Replied-Msgid:Subject:Date:To; b=IeRRin0FxqKFNKyW4UCZA4px8qXowHfV1ZzbDx4Yh6n+OyhhUpUk49z4IYHXTZ2nn+AkJIpcA0ijugp8kMqZLfya23dwvn5WZ2iDjxFbV9okBrfxk95kANpwMg4cG/92tqGTh9Pfh/4te6sgWThi19UZmLZeXbgfFCBXnsE6x7Q= ; Received: from [10.71.19.87] (chris_zavatson@166.205.137.197 with xymcookie) by smtp105-mob.biz.mail.ne1.yahoo.com with SMTP; 05 Apr 2011 11:55:30 -0700 PDT X-Yahoo-SMTP: 076hgjCswBC.G6e0vm7vgvZ9JJ0zmeBo_Oyw X-YMail-OSG: a9n7HrUVM1lUqPe2Njexr2GPm8BxR0VH1VhqKkRG5JMd7yj HWH87o5di7T9jCunMvlW0pKsGxOKdo925m_YMOg7zEjeECbYnlYCBNIb8LoW JhhP9ptMyDoZqlmGq6ehLaBQglziwj9JNcxZ.Yfjy3EzAT4j5Gv8qc_ZDG9b HW2.52kAyZuEpyyAg4fKVyTrPS54xaUazFuWnAbBrZ.f5UVTHAuKHnaCULIm YsFioK.Xdc.nds9goyuYubst_pr_5U_E5nWa1mPL5hPDK31IxWsnzqrfUk8j KgAVwMRQHkuCxhstm6SnX4v1HyeSYoMsnpFRJKfZGn2dC81CZJQQGZdI- X-Yahoo-Newman-Property: ymail-3 References: In-Reply-To: X-Apple-Yahoo-Original-Message-Folder: Inbox Mime-Version: 1.0 (iPad Mail 8C148) Content-Type: multipart/alternative; boundary=Apple-Mail-3--547502067 Content-Transfer-Encoding: 7bit X-Original-Message-Id: <789CF479-004A-40AA-B999-6C59E1C19296@yahoo.com> X-Mailer: iPad Mail (8C148) From: Chris X-Apple-Yahoo-Replied-Msgid: 1_11506679_AEdVv9EAATNZTZqdUgjrqigosKs Subject: Re: [LML] Re: LNC2 Gear Hydraulics X-Original-Date: Tue, 5 Apr 2011 11:55:21 -0700 X-Original-To: Lancair Mailing List --Apple-Mail-3--547502067 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 I would like to extend the offer to the whole group. I think the entire com= munity would benefit from understanding why some pumps are allowing the syst= em to lock up. If anyone has a pump that exhibits this behavior and could p= art with it for a week, I am willing to check it out on the test stand and e= xamine the internal configuration. Chris Zavatson N91CZ 360std www.N91CZ.net Sent from my iPad On Apr 4, 2011, at 9:40 PM, randy snarr wrote: > Chris, > I might take you up on that this winter as I dont want to ground the plane= now that flying season in here. Very kind offer.. > I am curious as well.. > Randy Snarr >=20 >=20 > "Flight by machines heavier than air is unpractical and insignificant, if n= ot utterly impossible" > -Simon Newcomb, 1902 >=20 > --- On Mon, 4/4/11, Chris Zavatson wrote: >=20 > From: Chris Zavatson > Subject: [LML] Re: LNC2 Gear Hydraulics > To: lml@lancaironline.net > Date: Monday, April 4, 2011, 1:42 PM >=20 > Randy, > I don't doubt your observations. I am just really curious what is differe= nt in your pump. The only way I can see this happening is if the spool does= n't stay put after the pump shuts down (slide 21 from my previous post). If t= he spool goes back to center both high and low circuits become isolated. On= ce that happens, temperature rise or and internal leak can lock out the pump= . > I've had my low side pressure go off the scale of the pressure gauge (1,20= 0+ psi) while he plane got baked in my old hangar. The high side remained a= t zero. Similarly when descending into hot desert air from 18k, the high si= de has hit 2,000 psi. The low side remained at zero. When the spool remains= in place, this makes perfect sense. The non-operating side has a low resis= tance escape path and cannot retain pressure. I would love throw your pump o= n the test bench. Let me know if you are interested > I just did a more comprehensive video of thermal cycling for the hydraulic= system, retracted, extended, under heating and cooling. Time is sped up 2x= to keep the total length reasonable. Worth noting is that the non-active s= ide always remains at zero.=20 > http://www.youtube.com/watch?v=3DZF3g_uPCzLk > Chris > =20 > Chris Zavatson > N91CZ > 360std > www.N91CZ.net >=20 > From: randy snarr > To: lml@lancaironline.net > Sent: Sun, April 3, 2011 11:40:56 PM > Subject: [LML] Re: LNC2 Gear Hydraulics >=20 > Chris, > Both sides of my system rise and fall with temp... > This is why I installed a dump valve with an extra line that dumps to zero= pounds on both sides when opened rather than just equalize and still be und= er pressure. I too used a wrench a few times to release the pressure. I beli= eve this condition is a little worse in my plane as I replace the large fact= ory supplied hose with small tight stainless braid lines that most likely re= sist expansion more than the big factory rubber hoses... >=20 > RS >=20 > "Flight by machines heavier than air is unpractical and insignificant, if n= ot utterly impossible" > -Simon Newcomb, 1902 >=20 > --- On Fri, 4/1/11, Chris Zavatson wrote: >=20 > From: Chris Zavatson > Subject: [LML] Re: LNC2 Gear Hydraulics > To: lml@lancaironline.net > Date: Friday, April 1, 2011, 8:34 AM >=20 > Keith, > You should never have to resort to wrenches to get the wheels up =E2=80=93= and that is not just speaking from a safety perspective.=20 > The following is an extract and renumbered set of slides from a LOBO maint= enance seminar on the 320/360 hydraulic system. Slide 21 shows one possible= explanation for your system=E2=80=99s failure to retract. > =20 > http://www.n91cz.com/misc/LancairHydraulics-LML.pdf > =20 > Temperature changes will cause pressure to go up and down, but should only= affect the currently operating side of the system. The non-operating side s= hould be zero and remain zero unless there is some other failure or configur= ation issue. If both operating and non-operating sides are affected by tem= perature =E2=80=93 investigate.=20 > Note that earlier vintage pumps (~235 era) were internally different. > You may also find some of the following of interest: > =20 > http://www.n91cz.com/Hydraulics/Lancair_Hydraulics.htm > =20 > Chris Zavatson > N91CZ > 360std > www.N91CZ.net >=20 >=20 > From: Keith Smith > To: lml@lancaironline.net > Sent: Thu, March 31, 2011 12:24:59 PM > Subject: [LML] Re: LNC2 Gear Hydraulics >=20 > Quite possibly one of the best posts I've ever read. Thanks, Tom, for tak= ing the time so share those experiences! >=20 > I recently experienced the inability to raise the gear. A quick call to Ri= ck Argente (Lancair owner/builder in NJ) provided the solution...bleed the l= ine. He said it's a common issue when flying from cold locations (NJ) to war= mer destinations (Georgia). >=20 > I also get hear the pump activate in flight for a fraction of a second eve= ry 20-30 minutes or so, which I suspect points to a leak of some sort. >=20 > Keith Smith > N360JH --Apple-Mail-3--547502067 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8
I would like to extend the offer to the= whole group.  I think the entire community would benefit from understa= nding why some pumps are allowing the system to lock up.  If anyone has= a pump that exhibits this behavior and could part with it for a week, I am w= illing to check it out on the test stand and examine the internal configurat= ion.

Chris Zavatson
N91CZ
360st= d
www.N91CZ.net

Sent f= rom my iPad

On Apr 4, 2011, at 9:40 PM, randy snarr <randylsnarr@yahoo.com> wrote:
<= br>
Chris,
I might take you up on that this winter as I dont want to= ground the plane now that flying season in here. Very kind offer..
I am c= urious as well..
Randy Snarr


"Flight by machines heavier than air is unpractical and insignificant, if= not utterly impossible"
-Simon Newcomb, 1902

--- On Mon= , 4/4/11, Chris Zavatson <= chris_zavatson@yahoo.com> wrote:
<= br>From: Chris Zavatson <chri= s_zavatson@yahoo.com>
Subject: [LML] Re: LNC2 Gear Hydraulics
T= o: lml@lancaironline.net
Date: Monday, April 4, 2011, 1:42 P= M

Randy,
I don't doubt your observations.  I am just really curious what is= different in your pump.  The only way I can see this happening is if t= he spool doesn't stay put after the pump shuts down (slide 21 from my previo= us post). If the spool goes back to center both high and low circuits b= ecome isolated.  Once that happens, temperature rise or and internal le= ak can lock out the pump.
I've had my low side pressure go off the scale of the pressure gau= ge (1,200+ psi) while he plane got baked in my old hangar.  The hi= gh side remained at zero.  Similarly when descending into hot desert ai= r from 18k, the high side has hit 2,000 psi. The low side remained at z= ero.  When the spool remains in place, this makes perfect sense.  T= he non-operating side has a low resistance escape path and cannot retain pre= ssure.  I would love throw your pump on the test be= nch.   Let me know if you are interested
I just did a more comprehensive video of thermal cycling for the hydrau= lic system, retracted, extended, under heating and cooling.  Time i= s sped up 2x to keep the total length reasonable.  Worth noting is= that the non-active side always remains at zero. 
=20 =20
Chr= is
&nb= sp;
Chr= is Zavatson
N91= CZ
360= std
From: randy snarr <randylsnarr@yahoo.com>
To: lml@lancaironline.net
Sent: Sun, April 3= , 2011 11:40:56 PM
Subject:<= /b> [LML] Re: LNC2 Gear Hydraulics

<= /table>
Chris,
Both sides of my system rise and fall with temp= ...
This is why I installed a dump valve with an extra line that dumps to= zero pounds on both sides when opened rather than just equalize and still b= e under pressure. I too used a wrench a few times to release the pressure. I= believe this condition is a little worse in my plane as I replace the large= factory supplied hose with small tight stainless braid lines that most like= ly resist expansion more than the big factory rubber hoses...

RS
<= br>"Flight by machines heavier than air i= s unpractical and insignificant, if not utterly impossible"
-Simon= Newcomb, 1902

--- On Fri, 4/1/11, Chris Zavatson <chris_zavatson@yahoo.com> w= rote:

From: Chris Zavatson <chris_zavatson@yahoo.com>
Subject: [LML] Re: L= NC2 Gear Hydraulics
To: lml@lancaironline.net
Date: Friday= , April 1, 2011, 8:34 AM

Keith,

You should never have to resort to wrenches to= get the wheels up =E2=80=93and that is not just speaking from a safety pers= pective. 

The following is an extract and renumbered set of sl= ides from a LOBO maintenance seminar on the 320/360 hydraulic system.&= nbsp; Slide 21 shows one possible explanation for your system=E2=80=99= s failure to retract.

 

http://www.n91cz.com/misc/LancairHydraulics-LML.pdf

 

Temperature changes will cause pressure to go u= p and down, but should only affect the currently operating side of the syste= m.  The non-operating side should be zero and remain zero u= nless there is some other failure or configuration issue.   = If both operating and non-operating sides are affected by temperature= =E2=80=93 investigate. 

 Note that earlier vintage p= umps (~235 era) were internally different.

You may also find some of the following of interest:=

 

http://w= ww.n91cz.com/Hydraulics/Lancair_Hydraulics.htm

 

Chris Zavatson

N91CZ

360std

www.N91CZ.net


From: Keith Smith <keith.smith@gmail.com>
To: lml@lancaironline.net
Sent: Thu, March 3= 1, 2011 12:24:59 PM
Subject:= [LML] Re: LNC2 Gear Hydraulics

Quite possibly one of the b= est posts I've ever read.  Thanks, Tom, for taking the time so share th= ose experiences!

I recently experienced the inability to raise the ge= ar. A quick call to Rick Argente (Lancair owner/builder in NJ) provided the s= olution...bleed the line. He said it's a common issue when flying from cold l= ocations (NJ) to warmer destinations (Georgia).

I also get hear the p= ump activate in flight for a fraction of a second every 20-30 minutes or so,= which I suspect points to a leak of some sort.

Keith Smith
N360JH
=
= --Apple-Mail-3--547502067--