Return-Path: Received: from lanfear.nidlink.com ([216.18.128.7]) by ns1.olsusa.com (Post.Office MTA v3.5.3 release 223 ID# 0-64832U3500L350S0V35) with ESMTP id com for ; Thu, 13 Apr 2000 11:39:03 -0400 Received: from enaila.nidlink.com (root@enaila.nidlink.com [216.18.128.8]) by lanfear.nidlink.com (8.9.0/8.9.0) with ESMTP id IAA16450 for ; Thu, 13 Apr 2000 08:35:50 -0700 (PDT) Received: from regandesigns.com (tnt132-48.nidlink.com [216.18.132.48]) by enaila.nidlink.com (8.9.0/8.9.0) with ESMTP id IAA12915 for ; Thu, 13 Apr 2000 08:35:48 -0700 (PDT) Message-ID: <38F5CD11.F791623@regandesigns.com> Date: Thu, 13 Apr 2000 08:35:13 -0500 From: Brent Regan To: Lancair List Subject: Air Box Icing X-Mailing-List: lancair.list@olsusa.com Mime-Version: 1.0 <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> << Lancair Builders' Mail List >> <<<<<<<<<<<<<<<<--->>>>>>>>>>>>>>>> >> Jim commented on the last list: "Although there is no alternate air with this setup, if you get both of these large filters iced up, alternate air isn't going to help you -- you need a parachute." Parachute indeed. There is another icing effect that is unique to filters and not generally discussed. Ice crystal clogging. This occurs when you fly through stratus clouds in the flight levels. The ice crystals, which don't stick to the airframe, are caught in the filter, like dust, and clog it. If the accretion rate is greater than the sublimation rate then your manifold pressure will drop precipitously. If you don't have an alternate air door then you will need "lower". Be advised that drawing alternate air in the flight levels will cause a MP drop due to the higher density altitude of the hot air coming off of the engine. This drop will be less than that caused by a clogged filter. I am also thinking (although I have never witnessed this effect) that in a starved intake situation the turbo controller will be insisting on maintaining high MPs, causing the turbo to run at higher and higher pressure ratios, all the while the air mass flow is dropping. Can a compressor stall and flameout be far behind? I can say that a flameout at altitude is one most exciting events that you can have and live to tell of it. 8~O Alternate air doors, get them or wish you had. Regards Brent Regan >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> 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. >>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>