X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Received: from elasmtp-masked.atl.sa.earthlink.net ([209.86.89.68] verified) by logan.com (CommuniGate Pro SMTP 6.0.4) with ESMTP id 6182595 for lml@lancaironline.net; Fri, 05 Apr 2013 11:09:12 -0400 Received-SPF: none receiver=logan.com; client-ip=209.86.89.68; envelope-from=colyncase@earthlink.net DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=dk20050327; d=earthlink.net; b=Tlq/qjXmop6rsZlRTyEtNk3FkxtKhsREF6Be90kamJBbUf9Jm/4xCG4cJwt8WsIa; h=Received:From:Mime-Version:Content-Type:Subject:Date:In-Reply-To:To:References:Message-Id:X-Mailer:X-ELNK-Trace:X-Originating-IP; Received: from [72.92.131.242] (helo=[192.168.1.24]) by elasmtp-masked.atl.sa.earthlink.net with esmtpa (Exim 4.67) (envelope-from ) id 1UO8Fo-0001y6-TR for lml@lancaironline.net; Fri, 05 Apr 2013 11:08:37 -0400 From: Colyn Case Mime-Version: 1.0 (Apple Message framework v1085) Content-Type: multipart/alternative; boundary=Apple-Mail-200-320260084 Subject: Re: [LML] Re: Minimum MP for pressurization Date: Fri, 5 Apr 2013 11:08:36 -0400 In-Reply-To: To: "Lancair Mailing List" References: Message-Id: X-Mailer: Apple Mail (2.1085) X-ELNK-Trace: 63d5d3452847f8b1d6dd28457998182d7e972de0d01da9406d2527d630edec4f2473a95ad650f183350badd9bab72f9c350badd9bab72f9c350badd9bab72f9c X-Originating-IP: 72.92.131.242 --Apple-Mail-200-320260084 Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=windows-1252 awesome improvement. One more example that when you buy an = experimental, even if you are the second owner, you are the guy to make = sure it's really put together properly. Colyn On Apr 5, 2013, at 7:58 AM, PETER WILLIAMS wrote: hi there This thing about cabin pressure is interesting; i bought a sixteen year = old 4P and it was lousy on pressurization. my previous experience was = with a Cessna 340 with 4.2 differential pressure. that gave me a sea = level cabin at 10,500 feet after we found the leaks. in the 4P, Matthew found that a seam/joint behind the rear seat had = never, yea never been sealed. it leaked like a sieve for the last = sixteen years, there was a leak around the door and several firewall = leaks. so it may well be that the plane you fly may never has had full = pressure differential. or it had it and over time leaks developed; and = having maintained the twin to a high standard, i know from the = experience that the pressure vessel and systems always need attention. now i get sea level at about 12,500 and at 17,500 i have about 4,700 foot = cabin; i still think there is ground for improvement. As to speed: 17,500 feet 3,450 gross weight, 17.5 gph, 32" and 2250 rpm gives 260 = knots (same conditions at 3,850 gross 250 knots) 6,500 feet 3,450 gross 17,5 gph 32" and 2250 rpm gives a reliable = 238 knots (that one seems to never vary by more than a knot) i do not believe that my plane is leak free; it might be that we could = do a little better. what should be clear is that if you are not doing as well, it time to = check for leaks in the pressurization vessel. i love my 4p, put 62 hours in six months and will likely continue at = that rate or higher. and still learning and still cautious as hell. yours peter williams To: lml@lancaironline.net Date: Thu, 4 Apr 2013 14:56:53 -0400 From: pete@leapfrogventures.com Subject: [LML] Re: Minimum MP for pressurization In cruise I run my engine at 63% power, 23=94 map, 15 gph, 2400 rpm and = have no problem maintaining 5.5 psi cabin pressurization. =20 Pete =20 From: Dico Reijers [mailto:dico@internetworks.ca]=20 Sent: Wednesday, April 03, 2013 2:43 PM To: lml@lancaironline.net Subject: Minimum MP for pressurization =20 Hello all, I was looking through the TSIO-550 Power Settings Chart and noticed that = it said the min MP for pressurization was 31.5".... I'm just wondering = if this is true for all IVPs? I was up to FL170 the other day at 28.5" and the cabin was showing = perhaps 7800. Should I assume that if I was running at 31.5" that the = cabin might only have been showing perhaps 5000'? The reason I ask is = because I'm thinking if we're at FL170 and the cabin is pushing 8000, = then at FL250 (or even FL210) the cabin pressure would be well over = 10,000'. I had thought it might have been because I have a leaky cabin = or something.... but perhaps its because I'm being too cheap with the = fuel.... Thoughts? -dr --=20 Regards, Dico Reijers InternetWorks Ltd. 300 University Avenue Charlottetown PE, C1A 4M4 902-892-4671 (T) 888-368-9484 (F) www.internetworks.ca www.apartmentspei.com --Apple-Mail-200-320260084 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=windows-1252 awesome improvement.  One more example that = when you buy an experimental, even if you are the second owner, you are = the guy to make sure it's really put together = properly.

Colyn

On Apr 5, = 2013, at 7:58 AM, PETER WILLIAMS wrote:

hi there

This thing about cabin pressure is = interesting; i bought a sixteen year old 4P and it was lousy on = pressurization. my previous experience was with a Cessna 340 with 4.2 = differential pressure. that gave me a sea level cabin at 10,500 feet = after we found the leaks.

in the 4P, Matthew found that a = seam/joint behind the rear seat had never, yea = never been = sealed. it leaked like a sieve for the last sixteen years, there was a = leak around the door and several firewall leaks. so it may well be that = the plane you fly may never has had full pressure differential. or it = had it and over time leaks developed; and having maintained the twin to = a high standard, i know from the experience that the pressure vessel and = systems always need attention.

now
i get sea level at about = 12,500 and at 17,500 i have about 4,700 foot cabin; i still think there = is ground for improvement.

As to speed:

17,500 feet = 3,450 gross weight, 17.5 gph, 32" and 2250 rpm gives 260 knots  = (same conditions at 3,850 gross 250 knots)
6,500 feet  3,450 = gross   17,5 gph  32" and 2250 rpm gives  a reliable = 238 knots (that one seems to never vary by more than a knot)

i do = not believe that my plane is leak free; it might be that we could do a = little better.

what should be clear is that if you are not doing = as well, it time to check for leaks in the pressurization = vessel.

i love my 4p, put 62 hours in six months and will likely = continue at that rate or higher. and still learning and still cautious = as hell.

yours

peter williams

To: lml@lancaironline.net
Date: = Thu, 4 Apr 2013 14:56:53 -0400
From: pete@leapfrogventures.comSubject: [LML] Re: Minimum MP for pressurization

In cruise I run my engine at 63% power, 23=94 map, = 15 gph, 2400 rpm and have no problem maintaining 5.5 psi cabin = pressurization.

 

Pete

 

From: Dico Reijers = [mailto:dico@internetworks.ca] 
Sent: Wednesday, April 03, 2013 = 2:43 PM
To: lml@lancaironline.net
Subj= ect: Minimum MP = for pressurization

 

Hello = all,

I was looking through the TSIO-550 Power Settings Chart and = noticed that it said the min MP for pressurization was 31.5"....  = I'm just wondering if this is true for all IVPs?

I was up to = FL170 the other day at 28.5" and the cabin was showing perhaps = 7800.  Should I assume that if I was running at 31.5" that the = cabin might only have been showing perhaps 5000'?  The reason  = I ask is because I'm thinking if we're at FL170 and the cabin is pushing = 8000, then at FL250 (or even FL210) the cabin pressure would be well = over 10,000'.  I had thought it might have been because I have a = leaky cabin or something.... but perhaps its because I'm being too cheap = with the fuel....

Thoughts?

-dr



-- 
Regards,

Dico = Reijers

InternetWorks Ltd.
300 University = Avenue
Charlottetown
PE, C1A 4M4

902-892-4671 = (T)
888-368-9484 (F)

www.internetworks.ca
www.apartmentspei.com
<= /span>

= --Apple-Mail-200-320260084--