X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Wed, 03 Feb 2010 11:54:30 -0500 Message-ID: X-Original-Return-Path: Received: from elasmtp-junco.atl.sa.earthlink.net ([209.86.89.63] verified) by logan.com (CommuniGate Pro SMTP 5.3.2) with ESMTP id 4109384 for lml@lancaironline.net; Wed, 03 Feb 2010 09:28:04 -0500 Received-SPF: none receiver=logan.com; client-ip=209.86.89.63; envelope-from=colyncase@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=c8TyaRPPBVkL7rqbELd/7E4DcoI0SjT06knlY6h1AHdD7kEaxoJnH72Cp6IUStvv; h=Received:Message-ID:From:To:References:Subject:Date:MIME-Version:Content-Type:X-Priority:X-MSMail-Priority:X-Mailer:X-MimeOLE:X-ELNK-Trace:X-Originating-IP; Received: from [216.57.118.190] (helo=ccaselt3) by elasmtp-junco.atl.sa.earthlink.net with esmtpa (Exim 4.67) (envelope-from ) id 1NcgCW-0002F6-Kc for lml@lancaironline.net; Wed, 03 Feb 2010 09:27:28 -0500 X-Original-Message-ID: <847B10C8F10649B8BDAF6E760D85F08B@nvidia.com> From: "Colyn Case at earthlink" X-Original-To: "Lancair Mailing List" References: Subject: Re: [LML] Re: Airspeed sensing switch: Pressurization (IV-P) X-Original-Date: Wed, 3 Feb 2010 09:27:27 -0500 MIME-Version: 1.0 Content-Type: multipart/alternative; boundary="----=_NextPart_000_02B3_01CAA4B3.1A389EE0" X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2900.5843 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.5579 X-ELNK-Trace: 63d5d3452847f8b1d6dd28457998182d7e972de0d01da940762042a7c049245c538db6372ea18f67350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 216.57.118.190 This is a multi-part message in MIME format. ------=_NextPart_000_02B3_01CAA4B3.1A389EE0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Re: Airspeed sensing switch: Pressurization (IV-P)Thanks for the info = Jeff. Did you happen to note what MAP it takes to get ANY differential? Can you say more about the "puncture tape during flight" situation? = Does this mean you could not hold AS MUCH cabin differential with the = tape punctured? Does it also mean the dukes valve never fully closes? b.t.w. - I rechecked the pressure chart which shows that even at an = extremely high airport, ambient pressure is well over 20" Hg. so I'll = take back that you can actually get it on the ground with any = differential. ----- Original Message -----=20 From: Jeffrey Liegner, MD=20 To: lml@lancaironline.net=20 Sent: Wednesday, February 03, 2010 7:42 AM Subject: [LML] Re: Airspeed sensing switch: Pressurization (IV-P) I have flown with the Duke's Valve completely occluded via duct tape = fully across the rear seat opening (for several month, in fact, part fo = an experiment). I was ready to puncture the tape if needed. The cabin = did not over pressurize, but it would have above ~13,000' to ~15,000' = during power climb. The initial slam of higher pressure during power up = and take off was noticible, but not in excess of 3psi (it was just = immediately noted). Over pressurization at anytime was avoided with a = controlled reduction of the throttle (MAP) to demonstrate cabin pressure = correlation to MAP. Upon landing, with outflow still occluded, cabin = was always at airport ambient pressure before door seal was dropped. = Again, this zero differential is notable on short final, door seal = tight, Duke's outlet occluded, engine below 11.5". During flight, outlet occluded, a small puncture through the occluding = tape demonstrated brisk exiting air through the puncture out the Duke's = Valve, but without a rapid cabin decompression (like one might = experience with door seal deflation). At any altitude, door seal = deflation results in immediate cabin decompression and cabin climb to = current flying altitude. I also have a cabin alert above 10,000' and panel light notification. Jeff L ------=_NextPart_000_02B3_01CAA4B3.1A389EE0 Content-Type: text/html; charset="iso-8859-1" Content-Transfer-Encoding: quoted-printable Re: Airspeed sensing switch: Pressurization = (IV-P)
Thanks for the info Jeff.  Did you = happen to=20 note what MAP it takes to get ANY differential?
 
Can you say more about the "puncture = tape during=20 flight" situation?   Does this mean you could not hold AS MUCH = cabin=20 differential with the tape punctured?
Does it also mean the dukes valve never = fully=20 closes?
 
b.t.w. - I rechecked the pressure chart = which shows=20 that even at an extremely high airport, ambient pressure is well over = 20"=20 Hg.   so I'll take back that you can actually get it on the = ground=20 with any differential.
----- Original Message -----
From:=20 Jeffrey=20 Liegner, MD
Sent: Wednesday, February 03, = 2010 7:42=20 AM
Subject: [LML] Re: Airspeed = sensing=20 switch: Pressurization (IV-P)

I have flown with the Duke's Valve completely occluded via duct = tape=20 fully across the rear seat opening (for several month, in fact, part = fo an=20 experiment).  I was ready to puncture the tape if needed.  = The cabin=20 did not over pressurize, but it would have above ~13,000' to ~15,000' = during=20 power climb.  The initial slam of higher pressure during power up = and=20 take off was noticible, but not in excess of 3psi (it was just = immediately=20 noted).  Over pressurization at anytime was avoided with a = controlled=20 reduction of the throttle (MAP) to demonstrate cabin pressure = correlation to=20 MAP.  Upon landing, with outflow still occluded, cabin was always = at=20 airport ambient pressure before door seal was dropped.  Again, = this zero=20 differential is notable on short final, door seal tight, Duke's outlet = occluded, engine below 11.5".

During flight, outlet occluded, a small puncture through the = occluding=20 tape demonstrated brisk exiting air through the puncture out the = Duke's Valve,=20 but without a rapid cabin decompression (like one might experience = with door=20 seal deflation).  At any altitude, door seal deflation results in = immediate cabin decompression and cabin climb to current flying=20 altitude.

I also have a cabin alert above 10,000' and panel light=20 notification.

Jeff L
 
------=_NextPart_000_02B3_01CAA4B3.1A389EE0--