KRnetters, I've been watching all of the posts about venturis or IFR and I would like to offer a broader perspective to consider. In looking at a single engine IFR airplane there are typically four power sources that operate in addition to the basic engine:
1. the magneto converts rotary motion to electrical energy for spark 2. the vacuum pump converts rotary motion to air flow to power some instruments 3. the alternator converts rotary motion to electrical energy to power some aircraft systems 4. the battery stores electrical energy to power some aircraft systems. With this typical configuration you have alternative power sources for some system however they each operate independently from one another. What good is excess vacuum pump capacity when the alternator fails, or excess battery capacity when the vacuum pump fails? I have replaced these four power sources with two alternators and two batteries and have all aircraft systems electrically powered. The magneto is replaced with electronic ignition. The vacuum pump is replaced with a 400 VAC inverter to power an AC powered Horizon and DG. The turn coordinator is powered by 12VDC. This will provide the most flexibility in powering aircraft systems from different power sources when failures occur. Here are two links to my web site that show what I've done that might be of interest: The instrument panel (http://flyboybob.com/images/kr2/n52bl/electric%20and%20instrument/inst01.jp g) is IFR capable for training purposes. You can file IFR when the weather is VFR and do your flying in the clear. On long cross countries, it's nice to know that someone knows where I am, just in case I don't. The power distribution and wiring diagrams (http://flyboybob.com/kr2/wd0001.htm) show two battery busses, each with a separate battery and alternator that power the main bus. The main bus powers all engine critical systems directly as well as a separate avionics bus for comm, nav, and instruments. The avionics master has a backup circuit breaker to eliminate it as a single point of failure to all avionics. I'm going down into a secure bunker now to work on my KR2. The build it light and simple brigade can lock and load, my airplane factory is a hardened facility! Regards, Bob Lee _________________________ N52BL KR2 Suwanee, GA 91% done only 51% to go! Phone/Fax: 770/844-7501 mailto:b...@flyboybob.com http://flyboybob.com
