Return-Path: Received: from mtiwmhc10.worldnet.att.net ([204.127.131.17]) by truman.olsusa.com (Post.Office MTA v3.5.1 release 219 ID# 0-52269U2500L250S0V35) with ESMTP id com for ; Sun, 9 Jan 2000 20:43:22 -0500 Received: from default- ([12.74.130.58]) by mtiwmhc10.worldnet.att.net (InterMail v03.02.07.07 118-134) with SMTP id <20000110014822.HXPD8291@default->; Mon, 10 Jan 2000 01:48:22 +0000 Message-ID: <001201bf5b0d$24965e40$3a824a0c@default-> Reply-To: "John Wright" From: "John Wright" To: Cc: "LML" Subject: Re: Ice vs. altitude theoretical scenerio Date: Sun, 9 Jan 2000 18:50:57 -0700 X-Mailing-List: lancair.list@olsusa.com Mime-Version: 1.0 <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> Hank, Thanks for your comments. I think the alternate air door I referred to when I referenced the AD does draw in air from inside the cowl. I don't know exactly how it works, but when the air filter ices up, the vacuum? builds up enough to where it overpowers the magnetically operated door and it must open the alternate air door as a source of air for the engine. I had a bonanza that had an alternate air door that must have operated differently than your Mooney because I did have a situation where the air filter iced up , MP dropped about 2" and then everything operated normally again after the alt. air door opened. I am sure there are subscribers on this site that can tell us all exactly how it works. The posting that referenced the iv-p over Montana was true except I thought that it was over Colorado and when I heard him telling the story that the first thing he did was to open the manual alternate air door to avoid loss of air to the engine as his airplane was immediately covered with small hail stones. I would be interested to know if the group on this web site thinks a manual alt. air door in addition to the magnetically operated one is necessary and/or a good idea. John Wright Colorado Springs -----Original Message----- Re: Ice vs. altitude theoretical scenerio >John: >I am surprised that the IV-P is not equipped with an automatic bypass door >that takes air from the engine compartment. >>Hank - San Mateo, Ca. > >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> LML website: http://www.olsusa.com/Users/Mkaye/maillist.html Builders' Bookstore: http://www.buildersbooks.com/lancair Please send your photos and drawings to marvkaye@olsusa.com. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>