---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 01/16/10: 7 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:46 AM - Through-panel ATO fuses () 2. 07:55 AM - Re: Through-panel ATO fuses (rockyjs) 3. 10:04 AM - Encoder Certification (Steve Thomas) 4. 11:14 AM - Re: Encoder Certification (Bob Lee) 5. 12:27 PM - Re: Encoder Certification (Bruce Gray) 6. 03:55 PM - Re: 28v to 14v (Eric M. Jones) 7. 07:43 PM - Wires, wires, so many choices . . . (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 06:46:30 AM PST US From: Subject: AeroElectric-List: Through-panel ATO fuses 1/16/2010 Hello Matt, You wrote: "As has been discussed at length recently, mounting the fuses in the panel pretty much means that you also have to provide the pilot with replacement fuses, or demonstrate to the DAR that none of the fuses are critical to continued flight." If the aircraft is to be flown at night or IFR I don't understand how a decision by a DAR (documented or undocumented) could override the required wording in the aircraft's Operating Limitations and the resulting applicable wording in 14 CFR 91.205. >From the Operating Limitations: "After completion of Phase I flight testing, unless appropriately equipped for night and/or instrument flight in accordance with 91.205, this aircraft is to be operated under VFR, day only." >From 14 CFR 91.205 "(c) Visual flight rules (night). For VFR flight at night, the following instruments and equipment are required: (6) One spare set of fuses, or three spare fuses of each kind required, that are accessible to the pilot in flight." and "(d) Instrument flight rules. For IFR flight, the following instruments and equipment are required: (1) Instruments and equipment specified in paragraph (b) of this section, and, for night flight, instruments and equipment specified in paragraph (c) of this section." The requirement regarding placement of fuses and circuit breakers "..essential to safety in flight.." comes from 14 CFR 23 which provides the airworthiness standards for type certificated aircraft. 14 CFR 23.1357 Circuit protective devices reads: "(d) If the ability to reset a circuit breaker or replace a fuse is essential to safety in flight, that circuit breaker or fuse must be so located and identified that it can be readily reset or replaced in flight." and "(e) For fuses identified as replaceable in flight- (1) There must be one spare of each rating or 50 percent spare fuses of each rating, whichever is greater; and (2) The spare fuse(s) must be readily accessible to any required pilot." 14 CFR 23 does not apply to experimental amateur built aircraft. I conclude that if an experimental amateur built aircraft has ANY of the fuses installed in ANY of its electrical systems accessible to the pilot in flight then the pilot must carry the 91.205 regulatory required spare fuses. 'OC' Says: "The best investment we can make is the effort to gather and understand knowledge." ======================================================= Time: 10:52:50 AM PST US Subject: Re: AeroElectric-List: Through-panel ATO fuses From: "Matt Prather" Unrelated to your question....... skip........ As has been discussed at length recently, mounting the fuses in the panel pretty much means that you also have to provide the pilot with replacement fuses, or demonstrate to the DAR that none of the fuses are critical to continued flight. It also means that should someone suffer an electrical malfunction (which might or might not be related to an opened fuse), they may spend time diagnosing the problem in flight instead of flying the airplane - increasing risk. ..................... skip................. Regards, Matt- ________________________________ Message 2 _____________________________________ Time: 07:55:23 AM PST US Subject: AeroElectric-List: Re: Through-panel ATO fuses From: "rockyjs" I was also interested in placing some fuses through the panel. In searching I found these. You would have to manufacture a stand off, but I like the compactness. I also attempted to find the ones used in the RV-12 and was told it was proprietary. http://www.delcity.net/store/8!way-fuse-block/p_10823.a_1 Rocky Read this topic online here: http://forums.matronics.com/viewtopic.php?p=281802#281802 ________________________________ Message 3 _____________________________________ Time: 10:04:13 AM PST US From: Steve Thomas Subject: AeroElectric-List: Encoder Certification A message to Stan Sutterfield: You wrote last June: > This may not be the ideal forum for asking this question, but I'll try it > anyway. > > I want to certify my RV-8 for IFR flight. I know the FARs - I've looked at > them. > > I have the Blue Mountain EFIS One as primary instrumentation. > I have the Blue Mountain EFIS Lite as a backup. > Both EFISs are on different electrical busses - the main and the standby. > - > which can be tied together, if needed. > > I asked a local avionics guy about doing a pitot-static and transponder > > check for IFR. He said I would have to install a separate altimeter and > > encoder in order to get IFR certification. The EFIS has a built-in encod > er. > > Has anyone else encountered this obstacle? > > Stan Sutterfield There were several replies that mostly focused on finding the right avionics guy. I have the exact same setup in my panel as do you and am ready for certification. Can you share your experience? Are you certified and flying? Who did you use for your certification and how did you go about getting it? I am in Southern California, and anyone else who can offer any advice on this topic will be welcome. My local shop mostly deals with biz jets and large non-jets. I don't think they will be very helpful with an experimental. Also, exorbitantly expensive. Do I need a transponder cert for my DAR inspection? Can I fly somewhere else to get it done once I have flown off my hours? Steve Thomas ________________________________________________________________________ ________________________________ Message 4 _____________________________________ Time: 11:14:32 AM PST US From: "Bob Lee" Subject: RE: AeroElectric-List: Encoder Certification Steve, You wrote: << My local shop ... I don't think they will be very helpful with an experimental. Also, exorbitantly expensive. >> Never let what you think prevent you from asking. If you don't ask your local shop it's a 0% chance they will calibrate your system at a reasonable price. If you do ask them all they can say is yes or no so you've got a 50% chance they will help you at a reasonable price. Your odds of success are 50 times better if you ask! Regards, Bob Lee N52BL KR2 Suwanee, GA USA 92% done only 67% to go! ________________________________ Message 5 _____________________________________ Time: 12:27:50 PM PST US From: "Bruce Gray" Subject: RE: AeroElectric-List: Encoder Certification I would advise you to check with the EAA. This subject has been aired before. I essence, by passing the certification criteria (ramp test), it meets the FAA's standards. No TSO or separate encoder/altimeter is required. The EAA has chapter and verse. I would also suggest you find another shop who work on experimentals. Those heavy iron types are rather inflexible to new ideas. Bruce www.Glasair.org -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Bob Lee Sent: Saturday, January 16, 2010 2:13 PM Subject: RE: AeroElectric-List: Encoder Certification Steve, You wrote: << My local shop ... I don't think they will be very helpful with an experimental. Also, exorbitantly expensive. >> Never let what you think prevent you from asking. If you don't ask your local shop it's a 0% chance they will calibrate your system at a reasonable price. If you do ask them all they can say is yes or no so you've got a 50% chance they will help you at a reasonable price. Your odds of success are 50 times better if you ask! Regards, Bob Lee N52BL KR2 Suwanee, GA USA 92% done only 67% to go! ________________________________ Message 6 _____________________________________ Time: 03:55:44 PM PST US Subject: AeroElectric-List: Re: 28v to 14v From: "Eric M. Jones" Try Astrodyne for great low cost power supplies that will do what you want. -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones@charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=281851#281851 ________________________________ Message 7 _____________________________________ Time: 07:43:10 PM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Wires, wires, so many choices . . . > >It seems that sometimes people size the wire simply based on the >Volts, current draw of the device, and the length of the wire. You >give some lengthy example calculations that go deeper to include >resistance of various devices in the circuit. How do i know when >it's ok to "grab any wire chart and hook things up accordingly"? It's not that random a process. In EVERY wire sizing task one starts with design goals. For example, the case for navigation lights (used to be the most energy hungry system on the airplane - before LEDs), we consider a high-duty cycle system where we want the bulbs to operate close to their design values. Here, voltage drop rules-of-thumb for 5% sort of drive the decisions. For getting the engine started, its a very low duty cycle, highest POWER task on the airplane with variables such as temperature of engine oil and battery, potential for partially discharged battery, mixture management for lighting off the fires, no alternator to help out, installed weight, etc. Now our design goal is to minimize the time it takes to get the engine running irrespective of how much loss is tolerated. If we were to obsess over losses, perhaps AWG 0 wire would make us feel better, but that wire's ability to perform is only taxed while cranking the engine . . . the rest of the time it's dead weight on the airframe. For establishing design goals, you STILL want to be aware of where the energy comes from (chemical and/or electro-mechanical), who needs it and how you're going to use the various ingredients for success to get it all wired up while always aware of the holy grail of airframe systems design . . . minimum WEIGHT to still get the job done. >I hadn't noticed Z-32 before. Is that the standard for a rear >battery? I hadn't considered using a relay. If the bulk of the ebus >load is resistive, shouldn't a switch be able to handle the 10 amps >that the #14 wire can cary? Wouldn't a relay just be another >possible point of failure? I'll go that route if it's necessary, but >I would rather keep it simple at this point. The relay becomes a 'mini-contactor' for driving a remotely mounted bus. The rule-of-thumb for always hot wires in airplanes is 5A breakered, 7A fused and MINIMUM length for wires that carry more than that. LONG fat wires that attach to batteries get protected with a contactor at the battery. Your 14AWG feeder to a "heavy duty" e-bus is too fat and too long to be allowed to run always hot. The history of the e-bus began before we had SD-8 standby alternators and all electric panels. An e-bus load back then was 4-5 amps max . . . no contactor necessary. As the e-bus got bigger (supported by an 8A engine driven alternate power source) it looks more like the main bus in terms of feeders between the battery bus and the e-bus . . . and the mini-contactor is called for. >Ok, I'll use #2 wire to the starter, but why #4 at the battery? That >seems strange. Won't that negate the benefit of the longer piece of >#2? Let me guess at your answer: Is it because you're worried about >fatiguing the battery terminals and the voltage drop of those short >pieces of #4 is not very significant to the overall circuit, and the >temp rise is not really an issue? YES! >Is fatigue as much of an issue with more flexible welding cable? >The picture I have in my mind though is those pieces of #4 acting >like a traffic-jam to electron flow. is that incorrect? Yes, the voltage drop is greater . . . but if your battery were up front, you would wire the entire the entire suite of fat wires with 4awg. The batteries really like 4awg mechanically so there's a reason to retain them even if you up-size to 2awg for a remote battery. Actually, there are a lot of all metal airplanes with rear mounted batteries that use 4AWG, I've even seen a few Eze type aircraft with round-trip 4AWG wiring . . . but these are 'warm weather' airplanes. Now, could you use 2AWG battery jumpers . . . sure and they're probably fine too in WELDING cable. But I've seen two failures of the battery connector tabs when the batteries were wired with 2AWG, 22759 wire. Bob . . . ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.