X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Tue, 05 Apr 2011 00:40:17 -0400 Message-ID: X-Original-Return-Path: Received: from nm7-vm0.bullet.mail.sp2.yahoo.com ([98.139.91.192] verified) by logan.com (CommuniGate Pro SMTP 5.4c2) with SMTP id 4932869 for lml@lancaironline.net; Mon, 04 Apr 2011 23:27:39 -0400 Received-SPF: none receiver=logan.com; client-ip=98.139.91.192; envelope-from=randylsnarr@yahoo.com Received: from [98.139.91.64] by nm7.bullet.mail.sp2.yahoo.com with NNFMP; 05 Apr 2011 03:27:03 -0000 Received: from [98.139.91.36] by tm4.bullet.mail.sp2.yahoo.com with NNFMP; 05 Apr 2011 03:27:03 -0000 Received: from [127.0.0.1] by omp1036.mail.sp2.yahoo.com with NNFMP; 05 Apr 2011 03:27:03 -0000 X-Yahoo-Newman-Property: ymail-3 X-Yahoo-Newman-Id: 739154.51383.bm@omp1036.mail.sp2.yahoo.com Received: (qmail 42975 invoked by uid 60001); 5 Apr 2011 03:27:03 -0000 DomainKey-Signature:a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:X-YMail-OSG:Received:X-Mailer:Date:From:Subject:To:In-Reply-To:MIME-Version:Content-Type; b=BAW2Jz4vsrG3+yxerla08Vsvm7AujbEI5w/J522u+xIvnRjEswYD23eF+5n9Tgib0t76mXkuHAui2K1zDKrX51YFvsu9O/llbcODNwWbzUHOFvpD2XeRe0GpTD4CzC+oa5r4Ci6kqrF+7lpLIfHm6DRHjKnKsfZtwtZN08CTeE4=; X-Original-Message-ID: <107940.42917.qm@web111413.mail.gq1.yahoo.com> X-YMail-OSG: aG31MgAVM1kBqrcummwjrQskykXC4Tz0nfqdOYj1LRexHSj KpTBVe.S81ftfAGvci.54dmvjxqknWRe64o6EI7AcZEv7VU9KRnvyTBj3iMC gapXpjZRRAHWjh6ZVpF546eIGi1J5zjWwGxQnkocNmdkrbSbF_vTamSP05Et 5zUXbgeznUlF9B5YQ7Uh2eMftwjDKb4z0Zbji2.WARebn4_t7J3hbzl09ht1 PpXKGFMceOqOoq92qMDA_rrnh6ewHJ_B_RtZxL4tx6IJjzumIs44KgGv9PtR SbGzE6DX8kQhie1DediIRrB2WqSjBlr2.qEADzzI9JHi5djtUC_yQjl9cHJK odFqazcW5ZmMxbeiccc6CsB7tnZAGXJlbpXaMvnrE8kJJB50sP14ML20_brD Mb2je7GKk7QM.UQ-- Received: from [76.8.220.21] by web111413.mail.gq1.yahoo.com via HTTP; Mon, 04 Apr 2011 20:27:02 PDT X-Mailer: YahooMailClassic/12.0.2 YahooMailWebService/0.8.109.295617 X-Original-Date: Mon, 4 Apr 2011 20:27:02 -0700 (PDT) From: randy snarr Subject: Re: [LML] Re: LNC2 Gear Hydraulics X-Original-To: Lancair Mailing List In-Reply-To: MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="0-835138514-1301974022=:42917" --0-835138514-1301974022=:42917 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable 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 "Flight by machines heavier than air is unpractical and insignificant, if n= ot utterly impossible" -Simon Newcomb, 1902 --- On Mon, 4/4/11, Chris Zavatson wrote: From: Chris Zavatson Subject: [LML] Re: LNC2 Gear Hydraulics To: lml@lancaironline.net Date: Monday, April 4, 2011, 1:42 PM Randy,=0AI don't doubt your observations.=C2=A0 I am just really curious wh= at is different in your pump.=C2=A0 The only way I can see this happening i= s if the spool doesn't stay put after the pump shuts down (slide 21 from my= previous post).=C2=A0If the spool goes back to center both high and low ci= rcuits become isolated.=C2=A0 Once that happens, temperature rise or and in= ternal leak can lock out the pump.=0AI've=C2=A0had my low side pressure go = off the scale of the pressure gauge (1,200+ psi)=C2=A0while he plane got ba= ked in my old hangar.=C2=A0 The high side remained at zero.=C2=A0 Similarly= when descending into hot desert air from 18k, the high side has hit 2,000 = psi. The=C2=A0low side remained at zero.=C2=A0 When the spool remains in pl= ace, this makes perfect sense.=C2=A0 The non-operating side has a low resis= tance escape path and cannot retain pressure.=C2=A0 I would love=C2=A0throw= =C2=A0your pump=C2=A0on the=C2=A0test bench.=C2=A0=C2=A0 Let me know if you= are interested=0AI just did a more comprehensive video of thermal cycling = for the hydraulic system, retracted, extended, under heating and cooling.= =C2=A0=C2=A0Time is sped up=C2=A02x to keep the total length reasonable.=C2= =A0 Worth noting is that the non-active side always remains at zero.=C2=A0 = =0A=0A=0A =0A=0A=0A =0A=0Ahttp://www.youtube.com/watch?v=3DZF3g_uPCzLk=0ACh= ris=0A=C2=A0=0AChris Zavatson=0AN91CZ=0A360std=0Awww.N91CZ.net=0A =0A=0A=0AFrom: randy snarr To: lml@lancaironline.net Sent: Sun, April 3, 2011 11:40:56 PM Subject: [LML] Re: LNC2 Gear Hydraulics =0A=0A=0A=0AChris, 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 bel= ieve this condition is a little worse in my plane as I replace the large fa= ctory supplied hose with small tight stainless braid lines that most likely= resist expansion more than the big factory rubber hoses... RS "Flight by machines heavier than air is unpractical and insignificant, if n= ot utterly impossible" -Simon Newcomb, 1902 --- On Fri, 4/1/11, Chris Zavatson wrote: =0A From: Chris Zavatson Subject: [LML] Re: LNC2 Gear Hydraulics To: lml@lancaironline.net Date: Friday, April 1, 2011, 8:34 AM =0A=0A=0A=0A=0A=0AKeith,=0AYou should never have to resort to wrenches to g= et the wheels up =E2=80=93and that is not just speaking from a safety persp= ective.=C2=A0 =0AThe following is an extract and renumbered set of slides f= rom a LOBO maintenance seminar on the 320/360 hydraulic system.=C2=A0 Slide= 21 shows one possible explanation for your system=E2=80=99s failure to ret= ract.=0A=C2=A0=0Ahttp://www.n91cz.com/misc/LancairHydraulics-LML.pdf=0A=C2= =A0=0ATemperature changes will cause pressure to go up and down, but should= only affect the currently operating side of the system.=C2=A0 The non-oper= ating side should be zero and remain zero unless there is some other failur= e or configuration issue. =C2=A0=C2=A0If both operating and non-operating s= ides are affected by temperature =E2=80=93 investigate.=C2=A0 =0A=C2=A0Note= that earlier vintage pumps (~235 era) were internally different. =0AYou ma= y also find some of the following of interest:=0A=C2=A0=0Ahttp://www.n91cz.= com/Hydraulics/Lancair_Hydraulics.htm=0A=C2=A0=0AChris Zavatson=0AN91CZ=0A3= 60std=0Awww.N91CZ.net =0A =0A=0A=0AFrom: Keith Smith To: lml@lancaironline.net Sent: Thu, March 31, 2011 12:24:59 PM Subject: [LML] Re: LNC2 Gear Hydraulics Quite possibly one of the best posts I've ever read.=C2=A0 Thanks, Tom, for= taking the time so share those experiences! I recently experienced the inability to raise the gear. A quick call to Ric= k 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 wa= rmer destinations (Georgia). I also get hear the pump activate in flight for a fraction of a second ever= y 20-30 minutes or so, which I suspect points to a leak of some sort. Keith=0A Smith N360JH --0-835138514-1301974022=:42917 Content-Type: text/html; charset=utf-8 Content-Transfer-Encoding: quoted-printable
Chris,
I might take you up on that this wi= nter as I dont want to ground the plane now that flying season in here. Ver= y kind offer..
I am curious as well..
Randy Snarr


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

--- On Mon, 4/4/11, Chris Zavatson <chris_zavatson@y= ahoo.com> wrote:

From: Chris Zav= atson <chris_zavatson@yahoo.com>
Subject: [LML] Re: LNC2 Gear Hydr= aulics
To: lml@lancaironline.net
Date: Monday, April 4, 2011, 1:42 PM=

Randy,
=0A
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 the spool doesn't stay put after th= e pump shuts down (slide 21 from my previous post). If the spool goes = back to center both high and low circuits become isolated.  Once that = happens, temperature rise or and internal leak can lock out the pump.
= =0A
I've had my low side pressure go off the scale of the pressure= gauge (1,200+ psi) while he plane got baked in my old hangar.  T= he high side remained at zero.  Similarly when descending into hot des= ert air from 18k, the high side has hit 2,000 psi. The low side remain= ed at zero.  When the spool remains in place, this makes perfect sense= .  The non-operating side has a low resistance escape path and cannot = retain pressure.  I would love throw your pump on the&n= bsp;test bench.   Let me know if you are interested
=0A
= 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 side always remains at zero. 
=0A
=0A=0A =0A=0A=0A =0A
=0A
Chris
=0A
 
=0A
Chris Zavatson
=0A
N91CZ
=0A
360std
= =0A=0A

=0A
=0A
=0AFrom: randy s= narr <randylsnarr@yahoo.com>
To: lml@lancaironline.net
Sent: Sun, April 3, 2011 11:40:56 PM
Subject: [LML] Re: LNC2 Gear Hydraulics

=0A=0A=0A=0A
Chris,
Both sides of my system rise and f= all 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 equal= ize and still be 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 li= nes that most likely resist expansion more than the big factory rubber hose= s...

RS

"Flight by machin= es heavier than air is unpractical and insignificant, if not utterly imposs= ible"
-Simon Newcomb, 1902

--- On Fri, 4/1/11, Chris Za= vatson <chris_zavatson@yahoo.com> wrote:
=0A
From: Chris Zavatson <chris_zavatson@yahoo.com>
= Subject: [LML] Re: LNC2 Gear Hydraulics
To: lml@lancaironline.net
Dat= e: Friday, April 1, 2011, 8:34 AM

=0A
=0A=0A=0A=
= =0A
=0A

Keith,

=0A

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

=0A

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

= =0A

 

=0A

ht= tp://www.n91cz.com/misc/LancairHydraulics-LML.pdf

=0A

 

=0A

Temperature= changes will cause pressure to go up and down, but should only affect the = currently operating side of the system.  The non-operatin= g side should be zero and remain zero unless there is some other failure or= configuration issue.   If both operating and non-op= erating sides are affected by temperature =E2=80=93 investigate. = ;

=0A

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

=0A

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

=0A

 =

=0A

http://www.n91cz.com/Hydraulics/Lancair_Hydraulics.htm

=0A<= p style=3D"margin: 0in 0in 0pt;" class=3D"yiv577723153MsoNormal"> 

=0A

Chris = Zavatson

=0A

N91CZ

=0A

360std

=0A

www.N91CZ.net=


=0A

=0A
=0A=0AFrom: Keit= h Smith <keith.smith@gmail.com>
To: lml@lancaironline.net
Sent: Thu, March 31, 2011 12:24:59 PM
Subject: [LML] Re: LNC2 Gear Hydraulics<= br>

Quite possibly one of the best posts I've ever read.  Th= anks, Tom, for taking the time so share those experiences!

I recentl= y experienced the inability to raise the gear. A quick call to Rick Argente= (Lancair owner/builder in NJ) provided the solution...bleed the line. He s= aid it's a common issue when flying from cold locations (NJ) to warmer dest= inations (Georgia).

I also get hear the pump 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=0A Smith
N360JH
=
--0-835138514-1301974022=:42917--