X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 29 Mar 2012 13:46:13 -0400 Message-ID: X-Original-Return-Path: Received: from nm29-vm0.bullet.mail.ac4.yahoo.com ([98.139.52.248] verified) by logan.com (CommuniGate Pro SMTP 5.4.4) with SMTP id 5461107 for lml@lancaironline.net; Thu, 29 Mar 2012 10:05:41 -0400 Received-SPF: none receiver=logan.com; client-ip=98.139.52.248; envelope-from=n20087@yahoo.com Received: from [98.139.52.195] by nm29.bullet.mail.ac4.yahoo.com with NNFMP; 29 Mar 2012 14:05:05 -0000 Received: from [98.139.52.185] by tm8.bullet.mail.ac4.yahoo.com with NNFMP; 29 Mar 2012 14:05:05 -0000 Received: from [127.0.0.1] by omp1068.mail.ac4.yahoo.com with NNFMP; 29 Mar 2012 14:05:05 -0000 X-Yahoo-Newman-Id: 640015.20050.bm@omp1068.mail.ac4.yahoo.com Received: (qmail 64476 invoked from network); 29 Mar 2012 14:05:05 -0000 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=DKIM-Signature:X-Yahoo-Newman-Property:X-YMail-OSG:X-Yahoo-SMTP:Received:Subject:References:From:Content-Type:X-Mailer:In-Reply-To:Message-Id:Date:To:Content-Transfer-Encoding:Mime-Version; b=XfNsChbBKPnnWzwQ1miFdLe+Trq/ZnwqPWniRLsdp486OINbK+6FaC/h28iEfVGWuwqwD6DsFcjouEqxIaEPIZWzGMqUiriudOYJ4ONbNueEyom11isFPppyswTn36Zn2+b+s8nQOhpKyD2QEW2IRdjAgycp5b3oNHl/jKwCs8Y= ; X-Yahoo-Newman-Property: ymail-3 X-YMail-OSG: pyfoznYVM1kg2ZSzO4FU8QBNO3EbTJ0mZrxgtF2PBRv7fmQ OTYckU2lQ4aQCwbhYI5Uhu60IPoP1O5rhfgXBavcFiZDIhpH7HKIzsVt72.0 4.WK_hEaHN9cGVA5X8swz0x_jTvhhl_GhdmtWyQMK2RvU2wMOrH5R6XfyAB8 R3OffyjTzhsqWXBK1zy51d6MHkZq3lVJyhlGRVKD0JfsxZE0H0CkivuLwwUl mbSUNugtRy_lRN1itTCkjcERttZHXPnlZQ17Z1mKsAMBLpgyqbXYrNpJqN3J tRbnZyP4V1JSvqRWO3FQohQtf302h8bKFGBJi6mqjjOj5ERD_OH2Lw.Os0Vc vDAaBUVzAJBF.uewslY9JhpIGBGmLGwsUnIdRul8LD2VM.nUwD993B5R7cOm ut7ADzS._vHLJKlC8NoEt4fY- X-Yahoo-SMTP: NQQt3c2swBAKSrExoA1eZuT7_w-- Received: from [10.234.108.253] (n20087@192.88.212.49 with xymcookie) by smtp116-mob.biz.mail.ac4.yahoo.com with SMTP; 29 Mar 2012 07:05:04 -0700 PDT Subject: Re: [LML] Re: LNC2 gear diagnosis References: From: N20087 Content-Type: multipart/alternative; boundary=Apple-Mail-D58B57E5-09C3-496C-BC09-D7A303A64BFE X-Mailer: iPad Mail (9A334) In-Reply-To: X-Original-Message-Id: X-Original-Date: Thu, 29 Mar 2012 10:05:01 -0400 X-Original-To: Lancair Mailing List Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (1.0) --Apple-Mail-D58B57E5-09C3-496C-BC09-D7A303A64BFE Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 Danny=20 If you have to change the valve I suggest replacing it with a three way type= that will dump to the pump reservoir. This will eliminate a potential fail= ure mode in the pump. You can get the valve from Lancair. It is used on the= legacy and of much better quality than the earlier 360 valves Tom Sent from my iPad On Mar 29, 2012, at 9:02 AM, "Danny" wrote: > Nope, I took the NW actuator out of the system and installed a gauge on th= at pressure line to check. I also played with the dump valve today to see i= f a slight movement of the handle made a difference =E2=80=A6 it did. This w= eekend I=E2=80=99ll cap it and see what kind of pressure I get but my guess i= s that=E2=80=99s the problem. > =20 > Danny > LNC2-360, 550 hours > N 38=C2=B0 43' 25.7" > W 77=C2=B0 30' 38.6" > =20 > From: Sky2high@aol.com [mailto:Sky2high@aol.com]=20 > Sent: Wednesday, March 28, 2012 9:06 AM > To: lml@lancaironline.net > Subject: [LML] Re: LNC2 gear diagnosis > =20 > Danny, > =20 > =46rom what you reported it would seem that the nose gear actuator is the r= eal problem. How about the door actuators? One possible analysis is that y= ou don't see the 1200 psi because the leak is greater at the higher pressure= and then slows a bit as the pressure goes down or the actuator has its wors= e leak at full retraction and less when the piston is not at the full retrac= tion position... > =20 > Scott Krueger > =20 > In a message dated 3/27/2012 10:32:25 P.M. Central Daylight Time, danny@n1= 07sd.com writes: > If any of you have a suggestion, I=E2=80=99d appreciate your input. > =20 > On my last flight home, with no early signs of failure, my gear pump was t= ripping on about every 2 seconds to maintain pressure. I figured I had a le= aky actuator and would have to rebuild it to resolve this; no big deal. I f= ound one leaking and figured where there is one, there may be more. So, I=E2= =80=99m rebuilding all of them. But, before doing so, I put a gauge on the h= igh pressure side of the pump to see if I had internal leaks there too. Wha= t I found was that my pump will only pressurize to about 950 psi (should be ~= 1200 psi) and then it bleeds down slowly. I tried to adjust the pressure sw= itch but it made very little difference. To verify the bleeding, I isolated= all actuators out of the system except the nose wheel. I put the gauge on t= he high pressure side of the NW actuator line, selected gear up to pressuriz= e the system, and then quickly crawled under the plane to look at the gauge.= It was bleeding down so fast that by the time I got down there to look at i= t (~2 sec.), it had already lost about 200 psi and then bled down the rest o= f the way in about 7 more seconds. So, and here=E2=80=99s the question, do I= have a faulty gear dump valve, a leaky pump, or both? > =20 > =20 > Danny > LNC2-360, ~550 hours > N 38=C2=B0 43' 25.7" > W 77=C2=B0 30' 38.6" > =20 --Apple-Mail-D58B57E5-09C3-496C-BC09-D7A303A64BFE Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=utf-8
Danny 

If you = have to change the valve I suggest replacing it with a three way type that = will dump to the pump reservoir.  This will eliminate a potential = failure mode in the pump.  You can get the valve from Lancair. It is = used on the legacy and of much better quality than the earlier 360 = valves

Tom

Sent from my = iPad

On Mar 29, 2012, at 9:02 AM, =22Danny=22 <danny=40n107sd.com> = wrote:

<=21--=5Bif gte mso = 9=5D> 1024x768 <=21=5Bendif=5D--><=21--=5Bif gte mso 9=5D> Clean Clean false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 <=21=5Bendif=5D--><=21--=5Bif gte mso 9=5D> <=21=5Bendif=5D--><=21--=5Bif gte mso 10=5D><=21=5Bendif=5D--><=21--=5Bif gte mso 9=5D> <=21=5Bendif=5D--><=21--=5Bif gte mso 9=5D> <=21=5Bendif=5D-->

Nope, I took the NW = actuator out of the system and installed a gauge on that pressure line to = check.  I also played = with the dump valve today to see if a slight movement of the handle made a = difference =E2=80=A6 it did.  = This weekend I=E2=80=99ll cap it and see what kind of pressure I = get but my guess is that=E2=80=99s the = problem.

 

Danny

LNC2-360, 550 = hours

N 38=C2=B0 43' = 25.7=22

W 77=C2=B0 30' = 38.6=22

 

From: Sky2high=40aol.com = =5Bmailto:Sky2high=40aol.com=5D
Sent: Wednesday, March 28, 2012 = 9:06 AM
To: lml=40lancaironline.net
= Subject: =5BLML=5D Re: = LNC2 gear diagnosis

 

Danny,

 

From what you reported it would seem that the = nose gear actuator is the real problem.  How about the door = actuators?  One possible analysis is that you don't see the 1200 psi = because the leak is greater at the higher pressure and then slows a bit as = the pressure goes down or the actuator has its worse leak at full = retraction and less when the piston is not at the full retraction = position...

 

Scott = Krueger

 

In a message dated 3/27/2012 10:32:25 P.M. = Central Daylight Time, danny=40n107sd.com = writes:

If = any of you have a suggestion, I=E2=80=99d appreciate your = input.

 <= /p>

On my = last flight home, with no early signs of failure, my gear pump was = tripping on about every 2 seconds to maintain pressure.  I figured I had a leaky = actuator and would have to rebuild it to resolve this; no big deal.  I found one leaking and = figured where there is one, there may be more.  So, I=E2=80=99m rebuilding = all of them.  But, before = doing so, I put a gauge on the high pressure side of the pump to see if I = had internal leaks there too.  = What I found was that my pump will only pressurize to about 950 psi = (should be =7E1200 psi) and then it bleeds down slowly.  I tried to adjust the = pressure switch but it made very little difference.  To verify the bleeding, I = isolated all actuators out of the system except the nose wheel.  I put the gauge on the high = pressure side of the NW actuator line, selected gear up to pressurize the = system, and then quickly crawled under the plane to look at the = gauge.  It was bleeding = down so fast that by the time I got down there to look at it (=7E2 sec.), = it had already lost about 200 psi and then bled down the rest of the way = in about 7 more seconds.  = So, and here=E2=80=99s the question, do I have a faulty gear dump = valve, a leaky pump, or both?

 <= /p>

 <= /p>

Danny<= /p>

LNC2-360, =7E550 = hours

N 38=C2=B0 43' = 25.7=22

W 77=C2=B0 30' = 38.6=22

 <= /p>

= --Apple-Mail-D58B57E5-09C3-496C-BC09-D7A303A64BFE--