---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 12/08/16: 7 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:43 AM - Re: Alternator Field Circuit Fuse Blow (Robert L. Nuckolls, III) 2. 10:07 AM - Re: Alternator Field Circuit Fuse Blow (Valin Thorn) 3. 11:12 AM - Re: Alternator Field Circuit Fuse Blow (Robert L. Nuckolls, III) 4. 11:16 AM - Edge of the frontier . . . (Robert L. Nuckolls, III) 5. 12:53 PM - Re: Alternator Field Circuit Fuse Blow (Valin Thorn) 6. 05:55 PM - Audio Isolation Amplifier Boards (Robert L. Nuckolls, III) 7. 07:10 PM - Re: Alternator Field Circuit Fuse Blow (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 07:43:57 AM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Alternator Field Circuit Fuse Blow At 10:39 PM 12/7/2016, you wrote: >Thanks Bob! I'll coordinate with B & C. We have two L3RC-28 Linear >Regulators (flight and spare on shelf) -- so we'll send them both in >for adjustment, one at a time so the airplane stays in service. Good lick . . . > >Our fuses are crew accessible in flight. The tray pulls out from >the right side of the panel with all the fuse blocks facing the >pilot. The Primary Alternator Field fuse is the first one. So, >we'll go ahead and stay with the fuse unless there's another reason >to go CB. I can't find a good photo to show how it is set >up. These two photos should provide an idea. See the face plate >with a little pull ring on the right side? That's the fuse tray >face plate, a two foot long fuse tray slides out from there. The >second photo shows the fuse tray. You guys do good work. There's an aura of meticulous craftsmanship here. But I'm a little disappointed that you spent so much $time$ on the installation of components with a vanishingly small chance of offering any in-flight utility. I would caution that fiddling with fuses, breakers, or any other failure in flight is a potential prelude for a bad day in the cockpit. When something quits working, it is either (1) REALLY necessary for comfortable termination of flight or (2) no big deal. If the appliance falls in category (1) you need a backup for it . . . a Plan B. All appliances in the airplane have MANY ways to stop working that DO NOT operate the circuit protection. FBO shops are populated with airplanes having broke gizmos, most of which did not pop a breaker -and- even if they did, resetting the breaker would not return the appliance to service. 99.999% of all breakers/fuses in airplanes/cars/ boats/garden tractors will set there for the lifetime of the machine never having been called upon to do it's singular task: keep a wire from burning. Yet, there is a nagging urge to arrange things with a notion that in-flight diagnosis and failure mitigation is a good thing to do. I've read lots of dark-n-stormy night stories in the journals . . . I've had occasion to pick through the bits and pieces of un-intended contacts with the earth. All of the accidents I've worked on or studied with electrical factors were absolutely preventable by some combination of competent processes and/or simply having a Plan-B. That's a beautiful job on the fuse panel no doubt deserving of honors for craftsmanship. But my best wish for you is that when something stops working, that fuse panel is the FURTHEST thing from your mind while you concentrate on a comfortable termination of flight. Bob . . . ________________________________ Message 2 _____________________________________ Time: 10:07:14 AM PST US From: "Valin Thorn" Subject: RE: AeroElectric-List: Alternator Field Circuit Fuse Blow Thanks Bob. The entire interior of our Legacy is our own design and build with the exception of the avionics and joy stick mechanisms. It took many years of weekends. The instrument panel design and layout is ours but the fine work on the instrument panel's component installation, wiring and fuse tray was performed by Andre Todd at Aerotronics in Montana. Yes, I agree with your philosophy regarding resetting a tripped CB or fuse in flight. Even our nuisance trips of the field fuse weren't corrected until on the ground. Even though we built an EAB airplane, we figure there's a lot of wisdom in the FAR certification regulations and always tried to align with them. That's why we made the fuses accessible in flight and carry extra fuses with us in flight. "You guys do good work. There's an aura of meticulous craftsmanship here. But I'm a little disappointed that you spent so much $time$ on the installation of components with a vanishingly small chance of offering any in-flight utility." Not sure which low utility components you're referring to.? Maybe the airplane logo that lights up is one? We certainly did that in part because we think it's a cool little feature. It may not be clear that it lights up in a color to correspond to the caution and warning status - blue when no issues, yellow for cautions and red for warnings. The Garmin G3X Touch avionics systems will note on the screen when there's something out of limits - but, it's just a small little block of words on the PFD that are easy to miss. When the airplane logo changes color, one definitely can't miss it. We've actually been very happy with this feature. Other than that, our design requirements were for an IFR capable aircraft (no FIKI) with appropriate fault tolerance for critical functions. Thanks again for all you help! I'm about to call TJ at B &C to setup the LR adjustment. Valin From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: Thursday, December 8, 2016 8:42 AM Subject: RE: AeroElectric-List: Alternator Field Circuit Fuse Blow At 10:39 PM 12/7/2016, you wrote: Thanks Bob! I'll coordinate with B & C. We have two L3RC-28 Linear Regulators (flight and spare on shelf) -- so we'll send them both in for adjustment, one at a time so the airplane stays in service. Good lick . . . Our fuses are crew accessible in flight. The tray pulls out from the right side of the panel with all the fuse blocks facing the pilot. The Primary Alternator Field fuse is the first one. So, we'll go ahead and stay with the fuse unless there's another reason to go CB. I can't find a good photo to show how it is set up. These two photos should provide an idea. See the face plate with a little pull ring on the right side? That's the fuse tray face plate, a two foot long fuse tray slides out from there. The second photo shows the fuse tray. You guys do good work. There's an aura of meticulous craftsmanship here. But I'm a little disappointed that you spent so much $time$ on the installation of components with a vanishingly small chance of offering any in-flight utility. I would caution that fiddling with fuses, breakers, or any other failure in flight is a potential prelude for a bad day in the cockpit. When something quits working, it is either (1) REALLY necessary for comfortable termination of flight or (2) no big deal. If the appliance falls in category (1) you need a backup for it . . . a Plan B. All appliances in the airplane have MANY ways to stop working that DO NOT operate the circuit protection. FBO shops are populated with airplanes having broke gizmos, most of which did not pop a breaker -and- even if they did, resetting the breaker would not return the appliance to service. 99.999% of all breakers/fuses in airplanes/cars/ boats/garden tractors will set there for the lifetime of the machine never having been called upon to do it's singular task: keep a wire from burning. Yet, there is a nagging urge to arrange things with a notion that in-flight diagnosis and failure mitigation is a good thing to do. I've read lots of dark-n-stormy night stories in the journals . . . I've had occasion to pick through the bits and pieces of un-intended contacts with the earth. All of the accidents I've worked on or studied with electrical factors were absolutely preventable by some combination of competent processes and/or simply having a Plan-B. That's a beautiful job on the fuse panel no doubt deserving of honors for craftsmanship. But my best wish for you is that when something stops working, that fuse panel is the FURTHEST thing from your mind while you concentrate on a comfortable termination of flight. Bob . . . ________________________________ Message 3 _____________________________________ Time: 11:12:09 AM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Alternator Field Circuit Fuse Blow >Even though we built an EAB airplane, we figure >there=92s a lot of wisdom in the FAR certification >regulations and always tried to align with >them. That=92s why we made the fuses accessible >in flight and carry extra fuses with us in flight. Then you've misread the FARs. Quoting from Part 23 . . . --------------------------------- Sec. 23.1357 Circuit protective devices. (a) Protective devices, such as fuses or circuit breakers, must be installed in all electrical circuits other than-- (1) Main circuits of starter motors used during starting only; and (2) Circuits in which no hazard is presented by their omission. (b) A protective device for a circuit essential to flight safety may not be used to protect any other circuit. (c) Each resettable circuit protective device ("trip free" device in which the tripping mechanism cannot be overridden by the operating control) must be designed so that-- (1) A manual operation is required to restore service after tripping; and (2) If an overload or circuit fault exists, the device will open the circuit regardless of the position of the operating control. (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. (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. ------------------------- Okay, name any appliance in your project wherein failure of that device puts the outcome of your flight in peril. Assuming you have any such appliance, then what is your Plan B for dealing with the failure of that device when it DOESN'T pop a fuse? Given that there are dozens of ways in which an appliance of any criticality can fail that doesn't pop a breaker/fuse. If the device is critical to comfortable termination of flight, then you're advised to have a Plan B for dealing with its failure. It follows then that the artfully crafted aircraft will have NO SINGLE ELECTRICAL APPLIANCE where failure to function puts the airplane at risk. Hence making circuit protection for that (or any other) appliance crew accessible serves no purpose. >=93You guys do good work. There's an aura of >meticulous craftsmanship here. But I'm a little >disappointed that you spent so much $time$ on >the installation of components with a >vanishingly small chance of offering any in-flight utility.=94 > >Not sure which low utility components you=92re referring to=85? The fuse panel . . . Bob . . . ________________________________ Message 4 _____________________________________ Time: 11:16:15 AM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Edge of the frontier . . . Electric-Flight Record Heralds New Era Of Aviation Walter Extra Sets Record For Time To Climb To 3,000 Meters http://tinyurl.com/jlynhwm Walter Extra, the famous aerobatics pilot behind the Extra series of aerobatic planes, has set an FAI world record in the new field of Electric-powered planes. [] Launching from Schwarze Heide Airport near Dinslaken, Germany, on November 25, 2016 he flew a unique, battery-powered plane and climbed to 3,000m (approx. 9,842 feet) in a time of 4mins 22 seconds. In doing so, he broke the FAI world record for electric-powered planes that weigh between 500kg to 1,000kg (approx. 1,100 to 2,200 pounds). Remarkably the plane, an Extra 330LE, only made its maiden flight on June 24 of this year. That first flight was called a "technical milestone" by Siemens, the company behind the technology that powers the electric plane. "This day will change aviation," Frank Anton, head of eAircraft at Siemens, said at the time. "This is the first time that an electric aircraft in the quarter-megawatt performance class has flown." Siemens developed a new type of electric motor that weighs only 50kg (110 pounds) but delivers a continuous output of 260 kilowatts (approx. 230 horsepower) to power the Extra aerobatic plane. That is five times more than previous comparable systems. [] The new system means that hybrid-electric planes with four or more seats will now be possible. Flying the plane on its maiden flight and for the record was Walter Extra. An award-winning aerobatic pilot and chief designer and founder of Extra Flugzeugbau, a manufacturer of aerobatic aircraft, Extra gave his name to one of the most popular aerobatics aircraft in the sport. "I pour my heart, mind and soul into ensuring that each aircraft carrying my name is the very best that it can be," he has said. The development, initial flights and new world record point the way to an electric-powered future for some aircraft. The battery technology behind the Extra 330LE is scalable, and some industry figures expect to see electric-powered passenger aircraft carrying up to 100 people on short-haul routes of up to 1,000km (540nm) by 2030. In the air and without engine noise the experience is "almost silent" Extra said. Siemens said that they had partnered with Extra Flugzeugbau because aerobatics planes are "particularly well suited" to taking components to their limit, "testing them and enhancing their design". The world record belongs to the group of Electric records for Powered Airplanes with a take-off weight of 500kg to 1,000kg. (Source: FAI news release. Images provided by Siemens. Top: Frank Anton (right), who heads eAircraft within the next47 startup unit, congratulates pilot Walter Extra, who broke the world record in ascent on November 25. Bottom: Aircraft on record-breaking flight Bob . . . ________________________________ Message 5 _____________________________________ Time: 12:53:27 PM PST US From: "Valin Thorn" Subject: RE: AeroElectric-List: Alternator Field Circuit Fuse Blow Yes, the key phrase is, ".essential to safety in flight.". That phrase leaves things open to various interpretations. In my work we'd try and establish a more objective, measurable safety criteria to compare designs against. We would follow statements like "essential for safety in flight" with criteria of minimum levels of risk as broad as "Loss of Crew" and "Loss of Vehicle" and then break these down into component allocations to subsystems. Then we'd perform probabilistic risk assessments throughout the design cycles to evaluate if those risk targets were achievable with the vehicle's design. So this would at least create the illusion of some objective measure. But really, it was most useful to help see the elements in the designs that were the biggest influence in risks/safety. Could really never believe the numbers were accurate in an absolute measure. With that said, yes, all the components/appliances in our aircraft's electrical system that are critical to some flight phases have redundancy or operational mitigations that help make an good argument that none of them are essential to safety of flight. The failure of each one, though, likely results in some incremental increase in risks. Does it push it past the "essential" criteria? Is a 25% increase in risk make a function essential or is it 50% -- the FAA doesn't get that specific. And, it depends on what's going on during the flight when it occurs. If one's on a precision instrument approach in crummy weather, the probability of a successful approach and landing is higher with all normal systems available and operating. If I felt like I really needed a function/component for what was going on in a flight, I'd probably try and replace a blown fuse once in flight. So, I agree with you that a strong case can be made for not requiring accessibility in flight for CBs and fuses. I think this design decision was probably influenced by knowing that CBs are usually accessible and in taking the unusual aviation approach of using fuses, I wanted to at least preserve that aspect. It sure would have been easier to mount the fuse blocks on the avionics shelf than to make a deployable tray! Thanks for your penetrating discussion on this! Valin From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: Thursday, December 8, 2016 12:11 PM Subject: RE: AeroElectric-List: Alternator Field Circuit Fuse Blow Even though we built an EAB airplane, we figure there's a lot of wisdom in the FAR certification regulations and always tried to align with them. That's why we made the fuses accessible in flight and carry extra fuses with us in flight. Then you've misread the FARs. Quoting from Part 23 . . . --------------------------------- Sec. 23.1357 Circuit protective devices. (a) Protective devices, such as fuses or circuit breakers, must be installed in all electrical circuits other than-- (1) Main circuits of starter motors used during starting only; and (2) Circuits in which no hazard is presented by their omission. (b) A protective device for a circuit essential to flight safety may not be used to protect any other circuit. (c) Each resettable circuit protective device ("trip free" device in which the tripping mechanism cannot be overridden by the operating control) must be designed so that-- (1) A manual operation is required to restore service after tripping; and (2) If an overload or circuit fault exists, the device will open the circuit regardless of the position of the operating control. (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. (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. ------------------------- Okay, name any appliance in your project wherein failure of that device puts the outcome of your flight in peril. Assuming you have any such appliance, then what is your Plan B for dealing with the failure of that device when it DOESN'T pop a fuse? Given that there are dozens of ways in which an appliance of any criticality can fail that doesn't pop a breaker/fuse. If the device is critical to comfortable termination of flight, then you're advised to have a Plan B for dealing with its failure. It follows then that the artfully crafted aircraft will have NO SINGLE ELECTRICAL APPLIANCE where failure to function puts the airplane at risk. Hence making circuit protection for that (or any other) appliance crew accessible serves no purpose. "You guys do good work. There's an aura of meticulous craftsmanship here. But I'm a little disappointed that you spent so much $time$ on the installation of components with a vanishingly small chance of offering any in-flight utility." Not sure which low utility components you're referring to.? The fuse panel . . . Bob . . . ________________________________ Message 6 _____________________________________ Time: 05:55:09 PM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Audio Isolation Amplifier Boards I've had a number of folks express and interst in acquiring the boards to the DIY audio Isolation amplifier. Interested purchases can be made from our website at: http://tinyurl.com/cgr42l5 Put your order details in the Commends/Special Rquests box at the bottom of the form. The boards are $22 ea plus first class postage of $2.25 I'll plan on ordering boards on Monday . . . Assembly instructions for this project are available at: http://tinyurl.com/ngoo6hc Emacs! Perhaps the better term is 'unpopulated'. It looks like this when you're done. Emacs! Bob . . . No virus found in this message. Checked by AVG - www.avg.com Bob . . . ________________________________ Message 7 _____________________________________ Time: 07:10:55 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Alternator Field Circuit Fuse Blow With that said, yes, all the components/appliances in our aircraft's electrical system that are critical to some flight phases have redundancy or operational mitigations that help make an good argument that none of them are essential to safety of flight. The failure of each one, though, likely results in some incremental increase in risks. What is the probability of loss for primary system and it's Plan-B alternative in any single tank of fuel? FMEA doesn't deal with increments . . . you either got it or you don't. Does it push it past the "essential" criteria? Is a 25% increase in risk make a function essential or is it 50% -- the FAA doesn't get that specific. And, it depends on what's going on during the flight when it occurs. If one's on a precision instrument approach in crummy weather, the probability of a successful approach and landing is higher with all normal systems available and operating. If I felt like I really needed a function/component for what was going on in a flight, I'd probably try and replace a blown fuse once in flight. FMEA doesn't care about probabilities and flight conditions are irrelevant. If you have any devic ever critical to comfortable completion of flight, then you're well advised to have a back-up for it. In 850+ hours of flying rental airplanes, I've NEVER perceived an elevated level of risk for not having dug through the maintenance logs of the machines I've rented . . . because I was prepared to continue flight to airport of intended destination with a completely dark panel if necessary . . . not searching for the nearest piece of smooth pavement with a 200psi pucker-factor. The foundation on which all the z-figures are crafted encourages every builder to establish their own minimum equipment list for the most demanding use of the airplane. Then conduct an FMEA while avoiding worrisome and largely irrelevant reliability studies . . . assume that every piece of stuff you bolt to the airplane WILL fail at some point in time . . . then DESIGN IN failure tolerance. So, I agree with you that a strong case can be made for not requiring accessibility in flight for CBs and fuses. I think this design decision was probably influenced by knowing that CBs are usually accessible and in taking the unusual aviation approach of using fuses. But they are NOT all accessible. There are breakers and fuses all over biz jets that crew cannot reach. Heavy iron pilots are generally not allowed to reset ANY breaker (rarely allowed a single reset on some systems) but the foundation for EVERY system powered by ANY breaker stands on a Plan-B. It sure would have been easier to mount the fuse blocks on the avionics shelf than to make a deployable tray! My point exactly and a philosophy I have taught for decades. In dozens of similar discussions dating back to the AVSIG forum on Compuserve I have encouraged builders to craft a FAILURE TOLERANT airplane wherein no single appliance can deprive you of a comfortable termination of flight. The way I used rental aircraft (day/night VFR with occasional punch through for VFR over the top) this compliment of back-ups would let me fly with confidence whether the panel was lit up or not http://tinyurl.com/zqb4f3q While I was flying off a little airport Dee and I owned about 1989, I crafted some GPS aided approaches to our little chunk of asphalt using dual GPS315 handhelds. I demonstrated an ability to reliably acquire the approach environment under circling minimums . . . with radios totaling $300 and carried in my flight bag. It required preparation and planning with understanding of limits . . . but it wasn't difficult. Designing a failure tolerant electrical and instrumentation system isn't difficult either . . . made easier still when panel space used by breakers/fuses is freed up for electro-whizzies that DO something useful. 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.