X-Virus-Scanned: clean according to Sophos on Logan.com Return-Path: Sender: To: lml@lancaironline.net Date: Fri, 06 Jun 2008 15:50:44 -0400 Message-ID: X-Original-Return-Path: Received: from mta16.adelphia.net ([68.168.78.211] verified) by logan.com (CommuniGate Pro SMTP 5.2.3) with ESMTP id 2956061 for lml@lancaironline.net; Fri, 06 Jun 2008 08:23:54 -0400 Received-SPF: pass receiver=logan.com; client-ip=68.168.78.211; envelope-from=glcasey@adelphia.net Received: from [76.166.22.191] by mta16.adelphia.net (InterMail vM.6.01.05.04 201-2131-123-105-20051025) with ESMTP id <20080606122249.ZDWY10601.mta16.adelphia.net@[76.166.22.191]> for ; Fri, 6 Jun 2008 08:22:49 -0400 Mime-Version: 1.0 (Apple Message framework v753) In-Reply-To: References: Content-Type: multipart/alternative; boundary=Apple-Mail-46-372073868 X-Original-Message-Id: <196EDC5D-C4E3-4623-8D3D-C655CF157DB4@adelphia.net> From: Gary Casey Subject: Re: Selecting an EFIS X-Original-Date: Fri, 6 Jun 2008 05:23:11 -0700 X-Original-To: "Lancair Mailing List" X-Mailer: Apple Mail (2.753) --Apple-Mail-46-372073868 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII; delsp=yes; format=flowed I agree completely with the comment below. Many people will build a complex electrical system to avoid the vacuum pump, but having a pure mechanical system as a backup is protection against the time that all the electrics go away. I designed a system that would power a vacuum instrument without the use of a vacuum pump in a turbocharged aircraft. I ended up going naturally aspirated (both me and my engine :-), so I didn't implement the idea on mine. It is essentially a pressure regulator that picks from the higher of compressor discharge and atmospheric pressure for the high side and the lower of atmospheric and intake manifold pressure for the low side, always maintaining a constant differential pressure across the instruments. Therefore, the system will be powered all the time the engine is running regardless of power condition. I patented the idea, but then got no interest in the product at the time so I dropped it. Any interest out there now? Gary Casey > > ....... I can say that it is never a good idea to fly actual IMC > without mechanical backups ..... > > Regards > Brent Regan --Apple-Mail-46-372073868 Content-Transfer-Encoding: quoted-printable Content-Type: text/html; charset=ISO-8859-1 I agree completely with the comment below. =A0Many people will build a = complex electrical system to avoid the vacuum pump, but having a pure = mechanical system as a backup is protection against the time that all = the electrics go away. =A0I designed a system that would power a vacuum = instrument without the use of a vacuum pump in a turbocharged aircraft. = =A0I ended up going naturally aspirated (both me and my engine :-), so I = didn't implement the idea on mine. =A0It is essentially a pressure = regulator that picks from the higher of compressor discharge and = atmospheric pressure for the high side and the lower of atmospheric and = intake manifold pressure for the low side, always maintaining a constant = differential pressure across the instruments. =A0Therefore, the system = will be powered all the time the engine is running regardless of power = condition. =A0I patented the idea, but then got no interest in the = product at the time so I dropped it. =A0Any interest out there = now?
Gary Casey



....... I can say that it is never a good =A0idea= to fly actual IMC without mechanical backups .....

Regards
= Brent = Regan

= --Apple-Mail-46-372073868--