Return-Path: Received: from [207.30.182.76] (account ) by logan.com (CommuniGate Pro WebUser 4.0b1) with HTTP id 1247832 for ; Sat, 25 May 2002 16:40:14 -0400 From: "Marvin Kaye" Subject: Re: [LML] vacuum vs. electric To: lml X-Mailer: CommuniGate Pro Web Mailer v.4.0b1 Date: Sat, 25 May 2002 16:40:14 -0400 Message-ID: In-Reply-To: <003501c20429$bf6c20e0$0100000a@cfl.rr.com> MIME-Version: 1.0 Content-Type: text/plain; charset="ISO-8859-1"; format="flowed" Content-Transfer-Encoding: 8bit Posted for "Ted Noel" : Gary, Does your system work from the suction side of the turbo? That makes a lot of sense, and suggests that all-electric might not be so bright. As long as the stick is turning, you would have vacuum. How much can it create? Ted Noel All-electric L-IV-P ----- Original Message ----- From: "Gary Casey" > Lots of good posts on the subject - go to the "aero-electric" list as > suggested by some to get multiple pro all-electric opinions. On my ES I am > going to an electronic engine control, so it will have a redundant > electrical system, but still a vacuum gyro. Why? Mostly because I have > this (patented) pressure regulator that will operate vacuum gyros from a > turbocharged engine (mine is) with no vacuum pump. So the plane will be > sort of a flying test bed/tax write-off. Otherwise the all-electric scheme > would maybe be the way I would go. > > However, I believe you can fly safely with the older, cheaper systems. > Here's what I did on my Cessna for just that purpose: I have a vacuum > system with no backup and a standard electrical system (also no backup). > The backup for the vacuum system is my S-TEC autopilot, which I chose > specifically because it is all-electric, getting it's information from the > turn coordinator. The on/off button for the A/P is on the yoke so I don't > have to reach for it. I consider that to be more effective backup than a > backup vacuum system (more expensive, too - but the vacuum system won't fly > the plane for me). I consider the A/P to be almost a no-go item for an IFR > flight and I turn it on and check it on the ground as a pre-flight item. > The A/P is also the backup for the other single-failure-mode system; me. I > show regular right-seat passengers (my wife) how to turn on the A/P to level > the wings. For my ES I plan to install the Autotrak A/P system which has > internal electric gyros. I do change the vacuum pump every 700 hours for > peace of mind, but I see no statistical proof that it is a good prevention. > I've had both pump and instrument failures, including turn coordinators, > over the years. > > Gary Casey > ES project > C177RG > > > > ############################################################# > For archives see the LML website: http://www.lancaironline.net/maillist.html > LML Builders' Bookstore: http://www.buildersbooks.com/lancair >