X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 29 Mar 2012 09:02:45 -0400 Message-ID: X-Original-Return-Path: Received: from oproxy4-pub.bluehost.com ([69.89.21.11] verified) by logan.com (CommuniGate Pro SMTP 5.4.4) with SMTP id 5460280 for lml@lancaironline.net; Wed, 28 Mar 2012 16:29:31 -0400 Received-SPF: pass receiver=logan.com; client-ip=69.89.21.11; envelope-from=danny@n107sd.com Received: (qmail 16990 invoked by uid 0); 28 Mar 2012 20:28:53 -0000 Received: from unknown (HELO host295.hostmonster.com) (66.147.240.95) by cpoproxy1.bluehost.com with SMTP; 28 Mar 2012 20:28:53 -0000 Received: from pool-71-114-20-44.washdc.dsl-w.verizon.net ([71.114.20.44] helo=DannyLaptop) by host295.hostmonster.com with esmtpa (Exim 4.76) (envelope-from ) id 1SCzUB-0002d0-9I; Wed, 28 Mar 2012 14:28:53 -0600 From: "Danny" X-Original-To: "'Lancair Mailing List'" X-Original-Cc: References: In-Reply-To: Subject: RE: [LML] Re: LNC2 gear diagnosis X-Original-Date: Wed, 28 Mar 2012 16:28:47 -0400 X-Original-Message-ID: <006d01cd0d21$626f36f0$274da4d0$@com> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_006E_01CD0CFF.DB5D96F0" X-Mailer: Microsoft Office Outlook 12.0 Thread-Index: Ac0M435RqrJkUjWUROuFms85IFI5xgAPZTFA Content-Language: en-us X-Identified-User: {3234:host295.hostmonster.com:wunderwe:n107sd.com} {sentby:smtp auth 71.114.20.44 authed with danny@n107sd.com} This is a multi-part message in MIME format. ------=_NextPart_000_006E_01CD0CFF.DB5D96F0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable 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. =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 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... =20 Scott Krueger =20 In a message dated 3/27/2012 10:32:25 P.M. Central Daylight Time, = danny@n107sd.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 = 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 ~1200 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 (~2 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? =20 =20 Danny LNC2-360, ~550 hours N 38=C2=B0 43' 25.7" W 77=C2=B0 30' 38.6" =20 ------=_NextPart_000_006E_01CD0CFF.DB5D96F0 Content-Type: text/html; charset="utf-8" Content-Transfer-Encoding: quoted-printable

Nope, I took the NW actuator out of the = system and installed a gauge on that pressure line to check.=C2=A0 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.=C2=A0 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"

W 77=C2=B0 30' = 38.6"

 

From: Sky2high@aol.com = [mailto:Sky2high@aol.com]
Sent: Wednesday, March 28, 2012 = 9:06 AM
To: = lml@lancaironline.net
Subject: [LML] 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@n107sd.com = writes:

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

 

On my = last flight home, with no early signs of failure, my gear pump was = tripping on about every 2 seconds to maintain pressure.=C2=A0 I figured I had a leaky = actuator and would have to rebuild it to resolve this; no big deal.=C2=A0 I found one leaking and figured = where there is one, there may be more.=C2=A0 So, I=E2=80=99m rebuilding all = of them.=C2=A0 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.=C2=A0 = What I found was that my pump will only pressurize to about 950 = psi (should be ~1200 psi) and then it bleeds down slowly.=C2=A0 I tried to adjust the pressure = switch but it made very little difference.=C2=A0 To verify the bleeding, I = isolated all actuators out of the system except the nose wheel.=C2=A0 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.=C2=A0 It was bleeding = down so fast that by the time I got down there to look at it (~2 sec.), = it had already lost about 200 psi and then bled down the rest of the way = in about 7 more seconds.=C2=A0 = So, and here=E2=80=99s the question, do I have a faulty gear dump = valve, a leaky pump, or both?

 

 

Danny

LNC2-360, ~550 = hours

N 38=C2=B0 43' = 25.7"

W 77=C2=B0 30' = 38.6"

 

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