X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Thu, 27 May 2010 14:14:05 -0400 Message-ID: X-Original-Return-Path: Received: from smtp-auth-03.mx.pitdc1.expedient.net ([206.210.66.136] verified) by logan.com (CommuniGate Pro SMTP 5.3.7) with ESMTPS id 4327990 for lml@lancaironline.net; Thu, 27 May 2010 09:28:46 -0400 Received-SPF: none receiver=logan.com; client-ip=206.210.66.136; envelope-from=rpastusek@htii.com Received: from HTBOB001 (static-72-66-86-7.washdc.fios.verizon.net [72.66.86.7]) by smtp-auth-03.mx.pitdc1.expedient.net (Postfix) with ESMTPSA id 9B9A17C81A for ; Thu, 27 May 2010 09:28:10 -0400 (EDT) From: "Robert Pastusek" X-Original-To: "'Lancair Mailing List'" References: In-Reply-To: Subject: RE: [LML] Re: Pressurization problem X-Original-Date: Thu, 27 May 2010 09:28:10 -0400 X-Original-Message-ID: <09e401cafda0$736d5460$5a47fd20$@com> MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_09E5_01CAFD7E.EC5BB460" X-Mailer: Microsoft Office Outlook 12.0 Thread-Index: Acr9mV50CgaaDfStRd2G2wy2TLdalwABtRfA Content-Language: en-us This is a multi-part message in MIME format. ------=_NextPart_000_09E5_01CAFD7E.EC5BB460 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable It almost always seems to be the little things=85 J =20 Thanks for the note back! =20 Bob =20 =20 From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of zoelt@sio.midco.net Sent: Thursday, May 27, 2010 6:01 AM To: lml@lancaironline.net Subject: [LML] Re: Pressurization problem =20 To all who replied. =20 Problem turned out to be a loose set screw in back of the = pressure(altitude) controller. Gear and static switches were wired out of the circuit so = never would have stopped pressurization any way. Once the controller travel = was adjusted and set screw tightened we could close the valve, initiate a = =BD psi differential at 1500msl and c ontroller set to 0. Unit functioned flawlessly in flight to 220 and rapid descent (1500-1800 fps). Thanks to all who responded. Tim =20 _____ =20 From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of zoelt@sio.midco.net Sent: Tuesday, May 25, 2010 5:41 PM To: lml@lancaironline.net Subject: [LML] Re: Pressurization problem =20 Thanks Bob and everyone who responded. I=92ll post what I find out for everyone=92s education. Tim =20 _____ =20 From: Lancair Mailing List [mailto:lml@lancaironline.net] On Behalf Of Robert Pastusek Sent: Tuesday, May 25, 2010 7:00 AM To: lml@lancaironline.net Subject: [LML] Re: Pressurization problem =20 Tim wrote:=20 Cabin won=92t pressurize. Visitor shopping for a 4P was sitting in = cabin with a battery charger on the battery supposedly studying the cheltons but I suspect he was pushing every button and switch he could. Now pressure = valve won=92t close. I can hear the dump switch and gear handle switch both clicking in the valve but it doesn=92t move up or down. Removed the = valve and checked for travel. I can manually close it on the bench but it = immediately opens again. With pressurized air flowing in (vacume cleaner hooked up = in reverse) I can depress the valve with my fingers and almost get it to = seal but it immediately opens. Is there another safety switch in the pitot system somewhere? Any idea where? I=92d appreciate any advice. Thanks, Tim, N524JG, LNC4P, Ser# 411 =20 Tim, Are you sure you by-passed the gear-down switch? That=92s the most = likely cause of =93pressurization dump=94 when the gear is down. You can test = this by pulling the hydraulic pump circuit breaker; then [CAREFULLY and = COMPLETELY] bleeding down the hydraulic system with the flaps. (You can add a safety factor by putting a length of 2x2 wood in the nose gear scissors.) When = the hydraulic pressure is zero, by-pass the gear down-lock solenoid and = raise the gear handle. Then test the system again. In my airplane (depends on = how the system is wired, but this is =93standard=94), the switch that = controls the down-lock also controls power to the pressure controller. Could a wire = have come off one side of this switch=85it=92s behind the left side of the = center vertical console, just below the gear operating lever. Your report of =93clicking=94 above would seem to have already validated this part of = the system, but worth checking twice=85) Sorry I don=92t have another = idea=85 =20 BE SURE TO GET THE GEAR HANDLE BACK DOWN BEFORE RESTORING POWER TO THE HYDRAULIC SYSTEM. =20 Bob ------=_NextPart_000_09E5_01CAFD7E.EC5BB460 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable

It almost always seems to be the little things… = J

 

Thanks for the note back!

 

Bob

 

 

From:= Lancair = Mailing List [mailto:lml@lancaironline.net] On Behalf Of = zoelt@sio.midco.net
Sent: Thursday, May 27, 2010 6:01 AM
To: lml@lancaironline.net
Subject: [LML] Re: Pressurization problem

 

To all who replied.

 

Problem turned out to be a loose set screw in back of the pressure(altitude) controller.  Gear and static switches were wired = out of the circuit so never would have stopped pressurization any way.  = Once the controller travel was adjusted and set screw tightened we could close = the valve, initiate a =BD psi differential at 1500msl and c ontroller set to = 0.  Unit functioned flawlessly in flight to 220 and rapid descent (1500-1800 = fps).

Thanks to all who responded.

Tim

 

From:= Lancair = Mailing List [mailto:lml@lancaironline.net] On Behalf Of = zoelt@sio.midco.net
Sent: Tuesday, May 25, 2010 5:41 PM
To: lml@lancaironline.net
Subject: [LML] Re: Pressurization problem

 

Thanks Bob and everyone who responded.

I’ll post what I find out for everyone’s = education.

Tim

 

From:= Lancair = Mailing List [mailto:lml@lancaironline.net] On Behalf Of Robert = Pastusek
Sent: Tuesday, May 25, 2010 7:00 AM
To: lml@lancaironline.net
Subject: [LML] Re: Pressurization problem

 

Tim wrote:

Cabin won’t pressurize.  Visitor shopping for a 4P was sitting in = cabin with a battery charger on the battery supposedly studying the cheltons but I = suspect he was pushing every button and switch he could.  Now pressure = valve won’t close.  I can hear the dump switch and gear handle switch both = clicking in the valve but it doesn’t move up or down.  Removed the valve = and checked for travel.  I can manually close it on the bench but it = immediately opens again.  With pressurized air flowing in (vacume cleaner hooked up = in reverse) I can depress the valve with my fingers and almost get it to = seal but it immediately opens.  Is there another safety switch in the pitot = system somewhere?  Any idea where?

I’d appreciate any advice.

Thanks,<= /o:p>

Tim, N524JG,  LNC4P, Ser# 411

 

Tim,

Are you sure you by-passed the gear-down switch? = That’s the most likely cause of “pressurization dump” when the gear is down. =  You can test this by pulling the hydraulic pump circuit breaker; then =  [CAREFULLY and COMPLETELY] bleeding down the hydraulic system with the flaps. (You can add a safety = factor by putting a length of  2x2 wood in the nose gear scissors.) When = the hydraulic pressure is zero, by-pass the gear down-lock solenoid and = raise the gear handle. Then test the system again.  In my airplane (depends = on how the system is wired, but this is “standard”), the switch = that controls the down-lock also controls power to the pressure controller.  Could a = wire have come off one side of this switch…it’s behind the left = side of the center vertical console, just below the gear operating lever. Your report of “clicking” above would seem to have already validated this = part of the system, but worth checking twice…) Sorry I don’t have another = idea…

 

BE SURE TO GET THE GEAR HANDLE BACK DOWN BEFORE RESTORING = POWER TO THE HYDRAULIC SYSTEM.

 

Bob

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