---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Thu 02/17/05: 19 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:45 AM - Re: 02/07/05 A Forced Landing (Ken) 2. 06:57 AM - Re: 02/07/05 A Forced Landing (Robert L. Nuckolls, III) 3. 07:53 AM - Re: 02/07/05 A Forced Landing (Robert L. Nuckolls, III) 4. 07:53 AM - Re: 02/07/05 A Forced Landing (Robert L. Nuckolls, III) 5. 09:04 AM - Re: 02/07/05 A Forced Landing (Glaeser, Dennis A) 6. 09:24 AM - Audio isolation amp board (Dee L. Conger) 7. 09:37 AM - Re: Re: 02/07/05 A Forced Landing (Robert L. Nuckolls, III) 8. 09:44 AM - Re: Re: 02/07/05 A Forced Landing (WRBYARS@aol.com) 9. 10:03 AM - Re: Re: 02/07/05 A Forced Landing (Harley) 10. 10:04 AM - Re: Re: 02/07/05 A Forced Landing (Mickey Coggins) 11. 01:37 PM - Re: Re: 02/07/05 A Forced Landing (George Braly) 12. 01:38 PM - System analysis (John Swartout) 13. 01:39 PM - Re: Re: 02/07/05 A Forced Landing (Leo J. Corbalis) 14. 02:42 PM - Re: Re: 02/07/05 A Forced Landing (John Schroeder) 15. 04:33 PM - P mags & urethane adhesive (Rob W M Shipley) 16. 04:54 PM - Re: Re: 02/07/05 A Forced Landing (Wayne Sweet) 17. 04:54 PM - Re: Re: 02/07/05 A Forced Landing (Wayne Sweet) 18. 05:59 PM - Re: P mags & urethane adhesive (rv-9a-online) 19. 11:39 PM - Re: Re: 02/07/05 A Forced Landing (Frank & Dorothy) ________________________________ Message 1 _____________________________________ Time: 06:45:20 AM PST US From: Ken Subject: Re: AeroElectric-List: 02/07/05 A Forced Landing --> AeroElectric-List message posted by: Ken Ignoring everything else, the alternator field fuse popped. He apparently hasn't found a definate reason for that, such as a field short. Perhaps the slow characteristics of a C/B (as advocated here for alternator fields) might have helped but to stir the pot a bit it also occurs to me that the much maligned oem internal VR alternator doesn't have an external field circuit to cause difficulty... Ken Eric Ruttan wrote: >--> AeroElectric-List message posted by: "Eric Ruttan" > >At http://www.sdsefi.com/rv12.htm there is a section, most of the way down, >titled > >02/07/05 A Forced Landing > >You all might find the read interesting, especially the lessons learned. > >Eric > > ________________________________ Message 2 _____________________________________ Time: 06:57:42 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: 02/07/05 A Forced Landing --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 08:32 AM 2/17/2005 +0100, you wrote: >--> AeroElectric-List message posted by: Mickey Coggins > > >Hi Eric, > >Thanks for pointing out this excellent article. > >Mickey > >Eric Ruttan wrote: > > --> AeroElectric-List message posted by: "Eric Ruttan" > > > > > At http://www.sdsefi.com/rv12.htm there is a section, most of the way down, > > titled > > > > 02/07/05 A Forced Landing > > > > You all might find the read interesting, especially the lessons learned. > > > > Eric What may we deduce from this article that will assist us in deliberating our own projects? Let's see . . . ---------- COMMENTED EXCERPTS FROM THE ARTICLE---------- 02/07/05 A Forced Landing "This read 9.5 volts so I knew then that we had a charging system failure. At the time, I was not worried about making it to an airport, assuming that the alternator had failed just in the last few minutes and believing that I had 20-25 minutes of battery power remaining." What do we know as a matter of simple-ideas in the discussions on battery performance and capability? when a 12-volt lead-acid battery drops to 10.5 volts it's remaining capacity is less than 5% of the fully charged value IN IT'S PRESENT CONDITION. This means that if the battery is several years old and has a current best capacity equal to 2/3 of new, then 10.5 volts is less than 5% of 2/3 of new. In fact, it is likely that the alternator failed soon after takeoff from Springbank but I did not notice signs of the failure until the battery was well over half dead. It wasn't half dead . . . it was all dead. About 4-5 minutes later, the engine started to run rough as battery voltage was down to 6.5 volts. 2 minutes later (See? 20-25 minutes was totally wishful thinking.) Preliminary investigation showed that the alternator field fuse . . . Field Fuse? What style of ov protection is installed on this airplane? . . . was blown for reasons undetermined at this point although some swarf was resting on top of the fuse holder in close proximity. Whether this was the cause or simply dislodged from the impact will probably never be known. We'll be performing tests on the charging system when the aircraft is repaired again. Tests? To measure what? The low voltage warning light was likely ON for 10-15 minutes and remained unnoticed by me because I was busy recording AFR data. The warning light is not a flashing type which is much more likely to attract attention. A 95dB warning buzzer will now be added so that a charging system malfunction will be apparent immediately. I strongly recommend an aural warning vs. a light. The delay in noticing the failure resulted in the forced landing. I believed that I had 20-25 minutes of battery power remaining when the failure was detected but had more like 10 minutes at that point. Education is always expensive in terms of $time$ required to achieve it. Venturing into situations rife with unknowns can ratchet the cost of education up dramatically along with the potential for seriously hazardous outcomes. Pilots always talk of instructors throwing impossible multiple system failures and emergencies at them in training or in the simulator. Well, this time, we had such multiple, progressive system failures and did not recognize what was happening until the third device started giving odd readings. It is worth thinking about odd readings rather than dismissing them. You might save valuable time. Yup, here's the contrite and humble admission that the pilot was somehow derelict in his duty to process a rapidly changing stream of SYSTEMS information while attempting to BE A PILOT. My friend, the seeds for this incident were plowed deep, fertilized and watered well before you fueled the airplane that day. The ROOT CAUSE of this incident had nothing to do with your inability to deal with a basic FAILURE OF DESIGN and understanding of limits. In the dark-n-stormy night stories from the certified side of aviation, we NEVER read where a pilot writes to Cessna, Beech, Piper or the FAA and takes them to task for selling them a system that almost guarantees failure. Since this is YOUR project, please don't beat yourself up as PILOT but a trip to the woodshed as DESIGNER is certainly in order . . . We rely so much on GPS but the "Nearest Airport" feature does not help much without electrical power and a dark screen. Having a map handy and marking last known position every 10 miles is not a bad idea. Glass cockpit advocates take note on the reliance of these on electrical power. We had no time to Mayday or really squawk a comm failure before power was lost. This could be serious in controlled airspace. We had no battery backup as this was deemed unnecessary, thinking that the alternator failure would be immediately noticed and that I'd have 20-25 minutes of flight time to find a suitable landing spot or airport. A second 18 amp hour battery will be added with a separate switch, independent of the master solenoid. I was worried that the master solenoid would trip open at the low voltage, effectively signing everything off. Fortunately, the hold current required on these is quite low but this is an extra drain on the battery. Again, an assumption of facts not in evidence but easily deduced by dedicating a certain amount of $time$ to education. Most of the electrical devices were effectively offline at around 9 volts. Fortunately the SDS ECU and coil pack functioned down to the very last along with the fuel pumps, even at 6.5 volts where the battery is virtually dead. SDS has voltage compensation for the ignition and injector drivers which helped in this situation. Does your ECU have this? This isn't a question of how well your system performs at 6.5 volts or even 10.5 volts. It's a question of designing a system wherein voltage NEVER falls to these levels. Damage will be repaired. Systems will be changed. Checklists will be altered and training will be intensified. I pledge not to forget the lessons learned here and am very happy to still be here to write this. And we are very happy that you're here to share this with us and to fly again. It is apparent from the article that your understanding of the rest of the airframe is extensive and that you are conducting good development work in the finest tradition of the Skunk Works. Please join us on the AeroElectric-List . . . http://aeroelectric.com/consulting.html . . . so that you can tap the time, talent and resources of dozens of folks who will (and would have) assist you in sorting out lots of simple-ideas. The goal is to assemble them in to light, inexpensive, reliable and FAILURE TOLERANT electrical systems that REDUCE PILOT WORKLOAD to an absolute minimum and reduce probability of root cause of an accident originating in the electrical system. Kindest regards, Bob . . . ________________________________ Message 3 _____________________________________ Time: 07:53:49 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: 02/07/05 A Forced Landing --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 09:44 AM 2/17/2005 -0500, you wrote: >--> AeroElectric-List message posted by: Ken > >Ignoring everything else, the alternator field fuse popped. He >apparently hasn't found a definate reason for that, such as a field >short. Perhaps the slow characteristics of a C/B (as advocated here for >alternator fields) might have helped but to stir the pot a bit it also >occurs to me that the much maligned oem internal VR alternator doesn't >have an external field circuit to cause difficulty... >Ken The circuit breaker isn't recommended for field protection because of it's speed characteristics. It fits well with CROWBAR ov protection . . . which is subject to nuisance tripping. Any other form of ov protection might work well downstream of a fuse for field power . . . the assumption of facts not in evidence here is whether the fuse in question even carries field current. It's most likely in an alternator control line that carries mere milliamps of current to tell the alternator to turn ON . . . and taking power off that leadwire may or may not turn the alternator OFF. If we're privileged to know the detailed analysis of this incident, it may well be that some kind of FOD popped the fuse. If so, the outcome of this event would have been no different had the airplane been fitted with an LR-3/L40 system. It will be interesting to see if the author joins us here on the list so that (1) we can ask questions to guide his investigation and (2) we all get to share benefits of the facts discovered. Bob . . . ________________________________ Message 4 _____________________________________ Time: 07:53:51 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: 02/07/05 A Forced Landing --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 08:32 AM 2/17/2005 +0100, you wrote: >--> AeroElectric-List message posted by: Mickey Coggins > > >Hi Eric, > >Thanks for pointing out this excellent article. > >Mickey > >Eric Ruttan wrote: > > --> AeroElectric-List message posted by: "Eric Ruttan" > > > > > At http://www.sdsefi.com/rv12.htm there is a section, most of the way down, > > titled > > > > 02/07/05 A Forced Landing > > > > You all might find the read interesting, especially the lessons learned. > > > > Eric What may we deduce from this article that will assist us in deliberating our own projects? Let's see . . . ---------- COMMENTED EXCERPTS FROM THE ARTICLE---------- 02/07/05 A Forced Landing "This read 9.5 volts so I knew then that we had a charging system failure. At the time, I was not worried about making it to an airport, assuming that the alternator had failed just in the last few minutes and believing that I had 20-25 minutes of battery power remaining." What do we know as a matter of simple-ideas in the discussions on battery performance and capability? when a 12-volt lead-acid battery drops to 10.5 volts it's remaining capacity is less than 5% of the fully charged value IN IT'S PRESENT CONDITION. This means that if the battery is several years old and has a current best capacity equal to 2/3 of new, then 10.5 volts is less than 5% of 2/3 of new. In fact, it is likely that the alternator failed soon after takeoff from Springbank but I did not notice signs of the failure until the battery was well over half dead. It wasn't half dead . . . it was all dead. About 4-5 minutes later, the engine started to run rough as battery voltage was down to 6.5 volts. 2 minutes later (See? 20-25 minutes was totally wishful thinking.) Preliminary investigation showed that the alternator field fuse . . . Field Fuse? What style of ov protection is installed on this airplane? . . . was blown for reasons undetermined at this point although some swarf was resting on top of the fuse holder in close proximity. Whether this was the cause or simply dislodged from the impact will probably never be known. We'll be performing tests on the charging system when the aircraft is repaired again. Tests? To measure what? The low voltage warning light was likely ON for 10-15 minutes and remained unnoticed by me because I was busy recording AFR data. The warning light is not a flashing type which is much more likely to attract attention. A 95dB warning buzzer will now be added so that a charging system malfunction will be apparent immediately. I strongly recommend an aural warning vs. a light. The delay in noticing the failure resulted in the forced landing. I believed that I had 20-25 minutes of battery power remaining when the failure was detected but had more like 10 minutes at that point. Education is always expensive in terms of $time$ required to achieve it. Venturing into situations rife with unknowns can ratchet the cost of education up dramatically along with the potential for seriously hazardous outcomes. Pilots always talk of instructors throwing impossible multiple system failures and emergencies at them in training or in the simulator. Well, this time, we had such multiple, progressive system failures and did not recognize what was happening until the third device started giving odd readings. It is worth thinking about odd readings rather than dismissing them. You might save valuable time. Yup, here's the contrite and humble admission that the pilot was somehow derelict in his duty to process a rapidly changing stream of SYSTEMS information while attempting to BE A PILOT. My friend, the seeds for this incident were plowed deep, fertilized and watered well before you fueled the airplane that day. The ROOT CAUSE of this incident had nothing to do with your inability to deal with a basic FAILURE OF DESIGN and understanding of limits. In the dark-n-stormy night stories from the certified side of aviation, we NEVER read where a pilot writes to Cessna, Beech, Piper or the FAA and takes them to task for selling them a system that almost guarantees failure. Since this is YOUR project, please don't beat yourself up as PILOT but a trip to the woodshed as DESIGNER is certainly in order . . . We rely so much on GPS but the "Nearest Airport" feature does not help much without electrical power and a dark screen. Having a map handy and marking last known position every 10 miles is not a bad idea. Glass cockpit advocates take note on the reliance of these on electrical power. We had no time to Mayday or really squawk a comm failure before power was lost. This could be serious in controlled airspace. We had no battery backup as this was deemed unnecessary, thinking that the alternator failure would be immediately noticed and that I'd have 20-25 minutes of flight time to find a suitable landing spot or airport. A second 18 amp hour battery will be added with a separate switch, independent of the master solenoid. I was worried that the master solenoid would trip open at the low voltage, effectively signing everything off. Fortunately, the hold current required on these is quite low but this is an extra drain on the battery. Again, an assumption of facts not in evidence but easily deduced by dedicating a certain amount of $time$ to education. Most of the electrical devices were effectively offline at around 9 volts. Fortunately the SDS ECU and coil pack functioned down to the very last along with the fuel pumps, even at 6.5 volts where the battery is virtually dead. SDS has voltage compensation for the ignition and injector drivers which helped in this situation. Does your ECU have this? This isn't a question of how well your system performs at 6.5 volts or even 10.5 volts. It's a question of designing a system wherein voltage NEVER falls to these levels. Damage will be repaired. Systems will be changed. Checklists will be altered and training will be intensified. I pledge not to forget the lessons learned here and am very happy to still be here to write this. And we are very happy that you're here to share this with us and to fly again. It is apparent from the article that your understanding of the rest of the airframe is extensive and that you are conducting good development work in the finest tradition of the Skunk Works. Please join us on the AeroElectric-List . . . http://aeroelectric.com/consulting.html . . . so that you can tap the time, talent and resources of dozens of folks who will (and would have) assist you in sorting out lots of simple-ideas. The goal is to assemble them in to light, inexpensive, reliable and FAILURE TOLERANT electrical systems that REDUCE PILOT WORKLOAD to an absolute minimum and reduce probability of root cause of an accident originating in the electrical system. Kindest regards, Bob . . . ________________________________ Message 5 _____________________________________ Time: 09:04:03 AM PST US From: "Glaeser, Dennis A" Subject: AeroElectric-List: Re: 02/07/05 A Forced Landing --> AeroElectric-List message posted by: "Glaeser, Dennis A" I'm very relieved that no one was hurt, and glad that this incident is being shared for the benefit of all. >>The low voltage warning light was likely ON for 10-15 minutes and remained unnoticed by me because I was busy recording AFR data. IMHO this is the key statement in this incident. He had LV warning, but it was somehow not observed due to other distractions. Even a failure tolerant system requires that the failure be recognized in time to take appropriate action! >>The warning light is not a flashing type which is much more likely to attract attention. >>A 95dB warning buzzer will now be added so that a charging system malfunction will be apparent immediately. >>I strongly recommend an aural warning vs. a light. Two key Lessons Learned here. Neither are new, but I for one hadn't been thinking about aural warning. Learning occurs when you change your behavior based on the Lesson presented, so guess what's now on my list of things to do . . . Adding a buzzer in parallel with the warning light sounds simple enough. But since hearing protection will be worn in the cockpit, I have a some questions (these may be premature since I haven't done any investigation): 1) How would one add a buzzer that can be muted (it needs to be loud - so you need to be able to mute it so it doesn't become a distraction) 2) How would one add aural warning through the headset (audio panel / intercom) - which also can be muted. 3) What is the easiest way to make LEDs flash - just buy flashing LEDs - or is adding a flasher a 'better' way to go (better = more control, cheaper, easier, ...) Thanks, Dennis Glaeser Re: 02/07/05 A Forced Landing I'm very relieved that no one was hurt, and glad that this incident is being shared for the benefit of all. The low voltage warning light was likely ON for 10-15 minutes and remained unnoticed by me because I was busy recording AFR data. IMHO this is the key statement in this incident. He had LV warning, but it was somehow not observed due to other distractions. Even a failure tolerant system requires that the failure be recognized in time to take appropriate action! The warning light is not a flashing type which is much more likely to attract attention. A 95dB warning buzzer will now be added so that a charging system malfunction will be apparent immediately. I strongly recommend an aural warning vs. a light. Two key Lessons Learned here. Neither are new, but I for one hadn't been thinking about aural warning. Learning occurs when you change your behavior based on the Lesson presented, so guess what's now on my list of things to do . . . Adding a buzzer in parallel with the warning light sounds simple enough. But since hearing protection will be worn in the cockpit, I have a some questions (these may be premature since I haven't done any investigation): 1) How would one add a buzzer that can be muted (it needs to be loud - so you need to be able to mute it so it doesn't become a distraction) 2) How would one add aural warning through the headset (audio panel / intercom) - which also can be muted. 3) What is the easiest way to make LEDs flash - just buy flashing LEDs - or is adding a flasher a 'better' way to go (better more control, cheaper, easier, ...) Thanks, Dennis Glaeser ________________________________ Message 6 _____________________________________ Time: 09:24:35 AM PST US Subject: AeroElectric-List: Audio isolation amp board From: "Dee L. Conger" --> AeroElectric-List message posted by: "Dee L. Conger" Bob - is the circuit board for your isolation amp available? If so, where? Thanks, Dee L. Conger (858) 754-3010 Direct This email and any attachments thereto may contain private, confidential, and privileged material for the sole use of the intended recipient. Any review, copying, or distribution of this email (or any attachments thereto) by others is strictly prohibited. If you are not the intended recipient, please contact the sender immediately and permanently delete the original and any copies of this email and any attachments thereto. ________________________________ Message 7 _____________________________________ Time: 09:37:19 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: 02/07/05 A Forced Landing --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > >Two key Lessons Learned here. Neither are new, but I for one hadn't been >thinking about aural warning. Learning occurs when you change your >behavior based on the Lesson presented, so guess what's now on my list of >things to do . . . > >Adding a buzzer in parallel with the warning light sounds simple enough. >But since hearing protection will be worn in the cockpit, I have a some >questions (these may be premature since I haven't done any investigation): > >1) How would one add a buzzer that can be muted (it needs to be loud - so >you need to be able to mute it so it doesn't become a distraction) This opens the door to explore a feature of many of the world's larger and perhaps more sophisticated aircraft. Many of our airplanes at RAC have a Master Caution and Master Warning detection and annunciation system. An illuminated red WARNING and amber CAUTION push buttons are positioned centrally to both the pilot and copilot panels. If anything CHANGES on the annunciator panel, the changed item on annunciator -AND- the appropriate WARNING or CAUTION lights begin to flash. After the crew has reacted to the warning and observed the information presented, he/she may push the flashing WARNING or CAUTION button which causes all annunciations to stop flashing and illuniation for the WARNING/CAUTION buttons goes out. This feature is effective in bringing new data to the crew's attention. An annunciator panel may have several lights already on when some new event needs to be noted. Flashing the new data IN ADDITION to lighting the WARNING/CAUTION lights does a good job of beating the washtub. >2) How would one add aural warning through the headset (audio panel / >intercom) - which also can be muted. One could easily craft a master caution/warning system that outputs a warning tone to the autio system in conjunction with the flashing light. >3) What is the easiest way to make LEDs flash - just buy flashing LEDs - >or is adding a flasher a 'better' way to go (better more control, >cheaper, easier, ...) Build it into the driving circuitry. The Low Voltage Warning/ Aux Battery Management Module we offer builds the flasher into the LED driver. Further, the lamp fixture we supply uses a hi-intensity red LED and paragraph 5.3 of the installation instructions . . . http://aeroelectric.com/Catalog/AEC/9005/9005-701B.pdf . . . says "The lamp's small size is favorable to a mounting location right in front of the pilot . . . even if the lamp needs to be tucked between existing panel hardware." Perhaps I should be a bit more specific in the instructions and say that the lamp should be mounted directly in front of the pilot. We flash at about 3 flashes per second (recommended by human factors folks as most attention getting) and use a bright lamp. I'll suggest that had the aircraft discussed in the original article been fitted with the AEC9005-101 LVW/ABMM or its clone . . . (See http://aeroelectric.com/articles/lvwarn/LVWarn-ABMM.html and http://aeroelectric.com/articles/lvwarn/9021-620.pdf ) . . . the "forced landing" paragraphs would not have been written. Aural warnings are not necessarily a bad idea but before folks run out and look for bunches of buzzers to add to their lights, let's explore the options and value of making the lights more effective. Bob . . . ________________________________ Message 8 _____________________________________ Time: 09:44:05 AM PST US From: WRBYARS@aol.com Subject: Re: AeroElectric-List: Re: 02/07/05 A Forced Landing --> AeroElectric-List message posted by: WRBYARS@aol.com Perhaps I missed out on something earlier, however in my airplanes you could "loose", or turn off, ALL of the electrical system, and continue to fly as long as the gas held out (during VFR). The engine runs off of a magneto thus supplying It's own power and doesn't need a battery, etc. Confused, Bill Byars ________________________________ Message 9 _____________________________________ Time: 10:03:22 AM PST US From: Harley Subject: Re: AeroElectric-List: Re: 02/07/05 A Forced Landing --> AeroElectric-List message posted by: Harley Afternoon, Bill... I didn't read that article, but as far as planes in general are concerned...there are a lot of them using electronic ignitions now, instead of magnetos, or in addition to magnetos. These electronic ignitions require a source of power to work. Except for the P-Mag, of course . Harley Dixon WRBYARS@aol.com wrote: >--> AeroElectric-List message posted by: WRBYARS@aol.com > >Perhaps I missed out on something earlier, however in my airplanes you could >"loose", or turn off, ALL of the electrical system, and continue to fly as >long as the gas held out (during VFR). The engine runs off of a magneto thus >supplying It's own power and doesn't need a battery, etc. > >Confused, >Bill Byars > > > > No virus found in this outgoing message. Checked by AVG Anti-Virus. ________________________________ Message 10 ____________________________________ Time: 10:04:18 AM PST US From: Mickey Coggins Subject: Re: AeroElectric-List: Re: 02/07/05 A Forced Landing --> AeroElectric-List message posted by: Mickey Coggins Hi Bill, The guy was flying an auto conversion, which requires electricity to power the fuel pumps, the computer, and the fuel injection system, just like in your car. In fact, he is the manufacturer of the computer. Mickey WRBYARS@aol.com wrote: > --> AeroElectric-List message posted by: WRBYARS@aol.com > > Perhaps I missed out on something earlier, however in my airplanes you could > "loose", or turn off, ALL of the electrical system, and continue to fly as > long as the gas held out (during VFR). The engine runs off of a magneto thus > supplying It's own power and doesn't need a battery, etc. > > Confused, > Bill Byars > -- Mickey Coggins http://www.rv8.ch/ #82007 Wiring ________________________________ Message 11 ____________________________________ Time: 01:37:01 PM PST US Subject: RE: AeroElectric-List: Re: 02/07/05 A Forced Landing From: "George Braly" --> AeroElectric-List message posted by: "George Braly" Bob, A recent visit with the FAA reveals they are opposed to "flashing" warning or caution lights. They claim it is too easy to dismiss them as being simply "faulty" lights. Rather than lights indicating a fault. Regards, George -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Subject: Re: AeroElectric-List: Re: 02/07/05 A Forced Landing --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > >Two key Lessons Learned here. Neither are new, but I for one hadn't been >thinking about aural warning. Learning occurs when you change your >behavior based on the Lesson presented, so guess what's now on my list of >things to do . . . > >Adding a buzzer in parallel with the warning light sounds simple enough. >But since hearing protection will be worn in the cockpit, I have a some >questions (these may be premature since I haven't done any investigation): > >1) How would one add a buzzer that can be muted (it needs to be loud - so >you need to be able to mute it so it doesn't become a distraction) This opens the door to explore a feature of many of the world's larger and perhaps more sophisticated aircraft. Many of our airplanes at RAC have a Master Caution and Master Warning detection and annunciation system. An illuminated red WARNING and amber CAUTION push buttons are positioned centrally to both the pilot and copilot panels. If anything CHANGES on the annunciator panel, the changed item on annunciator -AND- the appropriate WARNING or CAUTION lights begin to flash. After the crew has reacted to the warning and observed the information presented, he/she may push the flashing WARNING or CAUTION button which causes all annunciations to stop flashing and illuniation for the WARNING/CAUTION buttons goes out. This feature is effective in bringing new data to the crew's attention. An annunciator panel may have several lights already on when some new event needs to be noted. Flashing the new data IN ADDITION to lighting the WARNING/CAUTION lights does a good job of beating the washtub. >2) How would one add aural warning through the headset (audio panel / >intercom) - which also can be muted. One could easily craft a master caution/warning system that outputs a warning tone to the autio system in conjunction with the flashing light. >3) What is the easiest way to make LEDs flash - just buy flashing LEDs - >or is adding a flasher a 'better' way to go (better more control, >cheaper, easier, ...) Build it into the driving circuitry. The Low Voltage Warning/ Aux Battery Management Module we offer builds the flasher into the LED driver. Further, the lamp fixture we supply uses a hi-intensity red LED and paragraph 5.3 of the installation instructions . . . http://aeroelectric.com/Catalog/AEC/9005/9005-701B.pdf . . . says "The lamp's small size is favorable to a mounting location right in front of the pilot . . . even if the lamp needs to be tucked between existing panel hardware." Perhaps I should be a bit more specific in the instructions and say that the lamp should be mounted directly in front of the pilot. We flash at about 3 flashes per second (recommended by human factors folks as most attention getting) and use a bright lamp. I'll suggest that had the aircraft discussed in the original article been fitted with the AEC9005-101 LVW/ABMM or its clone . . . (See http://aeroelectric.com/articles/lvwarn/LVWarn-ABMM.html and http://aeroelectric.com/articles/lvwarn/9021-620.pdf ) . . . the "forced landing" paragraphs would not have been written. Aural warnings are not necessarily a bad idea but before folks run out and look for bunches of buzzers to add to their lights, let's explore the options and value of making the lights more effective. Bob . . . --- --- ________________________________ Message 12 ____________________________________ Time: 01:38:29 PM PST US From: "John Swartout" Subject: AeroElectric-List: System analysis --> AeroElectric-List message posted by: "John Swartout" Bob and list: I am planning my electrical system and have just re-read AEC chapter 17 Electrical System Reliability, and STILL am having trouble deciding the ignition/aux battery/aux alternator mix. I think I need an algorithm for analyzing redundancy and/or a hierarchy of the most failure-prone primary electrical components. First, here's the application: O-360 powered day/night VFR bush plane with gravity-fed fuel (boost pump for TO & Ldg.) dual electronic ignitions, either EMAG/PMAG or two PMAGS but leaning towards one of each. All-electric panel, consisting of Dynon D1o-A EFIS with analog airspeed and altimeter backup, a skid/slip ball, magnetic and electronic compasses, and a GPS with moving map PDA ; and a Grand Rapids EIS. How many simultaneous electrical/electronic failures is it reasonable to guard against? Could an alternator or regulator failure smoke an electronic ignition--or both of them--thus taking down everything? If the one PMAG self-destructs, the engine becomes electrically dependent, but my single RG battery should keep the EMAG operating. If an alternator/regulator failure can't possibly damage the electronic ignitions, then the engine is not technically dependent on the aircraft electrical system and the engine can take care of itself temporarily. Per AEC, I shouldn't need two batteries if I use one good RG and take care of it and replace it annually. Bob says the failure of a fresh RG battery is about as likely as losing a prop bolt. That leaves the alternator/regulator. I gather that this is the most vulnerable link in the chain. The AEC list archives is awash with stuff on what to do about alternators that wig out. Granted that a B&C alternator would reduce the likelihood of an alternator failure, but "Nuckolls' first law of airplane systems design sez: Things break." So I consider backing up the alternator with an SD8 and overvoltage kit, for $500. That's on top of the $638 for the main alternator, an L40 and LR3 regulator, which might be very good but will someday croak. Heck, a V-belt could break-not the alternator's fault. So if I have a very reliable back-up alternator, why not realize some savings and install as the main alternator a $110 automotive 55-amp internally-regulated unit, with a crowbar circuit and maybe one of those Whack Jack things? I mean, some of us homebuilders are doing it to build a better mousetrap AND save money. One more thing. I estimate peak electrical load at about 19 amps (night landing with everything on). Rock bottom E-bus load about 5 amps. Maximum fuel endurance about 6 hours. Should I think about anything less than a 34 amp hour battery? Thanks to all who offer critiques. ________________________________ Message 13 ____________________________________ Time: 01:39:01 PM PST US From: "Leo J. Corbalis" Subject: Re: AeroElectric-List: Re: 02/07/05 A Forced Landing --> AeroElectric-List message posted by: "Leo J. Corbalis" When I built my Zodiac 601 HDS I put in a GRT engine monitor. The blinking light from no oil pressure was supposed to remind me turn off the battery switch. After the second flight, parked facing the late afternoon sun on the ramp, I missed the light and ran the battery totally flat. I put a simple 2 1/2 or 3 inch Radio Shack buzzer in paralell with the light. The light has a blinker circuit so just get a simple steady tone one. The buzzer is stuck to the back side of the panel with 3M double sided foam tape. Its been there 7 years. The buzzer is loud enough to hear clearly at full power thru my Peltor 7000 passive headset. The tone is probably higher than the ANR headsets try to cancel. Leo Corbalis ----- Original Message ----- From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: 02/07/05 A Forced Landing > --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > > > > >Two key Lessons Learned here. Neither are new, but I for one hadn't been > >thinking about aural warning. Learning occurs when you change your > >behavior based on the Lesson presented, so guess what's now on my list of > >things to do . . . > > > >Adding a buzzer in parallel with the warning light sounds simple enough. > >But since hearing protection will be worn in the cockpit, I have a some > >questions (these may be premature since I haven't done any investigation): > > > > ________________________________ Message 14 ____________________________________ Time: 02:42:59 PM PST US Subject: Re: AeroElectric-List: Re: 02/07/05 A Forced Landing From: "John Schroeder" --> AeroElectric-List message posted by: "John Schroeder" On Thu, 17 Feb 2005 11:36:01 -0600, Robert L. Nuckolls, III wrote: > One could easily craft a master caution/warning system > that outputs a warning tone to the autio system in conjunction > with the flashing light. Bob - Do you know if anyone in the OBAM community or a supplier thereof has done such a system? I, for one, would love to have a kit available for an annunciator panel that has both a master caution/warning lamp and an aural output to the audio panel/intercomm. I suspect that there is something out there, but I have not heard of it. Several of the EFIS systems have audio and visual cues when certain systems mostly engine-related) go awry, but such things as baggage doors, main doors, ground power hooked up, redundant oil pressure warning circuitry, etc. could be worked into such a system. Thanks, John -- ________________________________ Message 15 ____________________________________ Time: 04:33:17 PM PST US From: "Rob W M Shipley" Subject: AeroElectric-List: P mags & urethane adhesive --> AeroElectric-List message posted by: "Rob W M Shipley" This enquiry is for Vern Little since my message direct to you was bounced since your mail box is reported as full! Your post on wiring the p-mags got me looking at your excellent web site and I noticed the use of the (?) Sika 295 to mount the temperature probe. I assume you used this for your canopy. Did you build a tipper or a slider and do you have any caveats to share since I plan on doing this with my tipper.. Rob Rob W M Shipley N919RV (res) Fuselage .....still! La Mesa, CA. (next to San Diego) P.S. I own an autoglass company and am familiar with the technical requirements of this class of adhesives. Do not archive. No virus found in this outgoing message. Checked by AVG Anti-Virus. ________________________________ Message 16 ____________________________________ Time: 04:54:11 PM PST US From: "Wayne Sweet" Subject: Re: AeroElectric-List: Re: 02/07/05 A Forced Landing --> AeroElectric-List message posted by: "Wayne Sweet" FWIW, this has been stated here before (most probably), but many are flying dual CDI systems with the addition of a DEDICATED backup battery that is used only in the event of a main power bus failure to power one CDI, AND as in my case, for starting to power one CDI. In fact I lost the alternator output (B-wire connector broke off) on a trip and flew 40 minutes while still on the main battery back to my home airport, after of course reducing the load to GPS and CDI's. Battery voltage never dropped below 12.6 V. Never had to use the 7.8 AH backup battery, but it was very reassuring just knowing it was there. I have Vision 800 engine instrumentation system that when the voltage drops below 13.0, a LOW VOLTAGE alert flashes. Wayne ----- Original Message ----- From: "Harley" Subject: Re: AeroElectric-List: Re: 02/07/05 A Forced Landing > --> AeroElectric-List message posted by: Harley > > Afternoon, Bill... > > I didn't read that article, but as far as planes in general are > concerned...there are a lot of them using electronic ignitions now, > instead of magnetos, or in addition to magnetos. These electronic > ignitions require a source of power to work. Except for the P-Mag, of > course . > > Harley Dixon > > WRBYARS@aol.com wrote: > >>--> AeroElectric-List message posted by: WRBYARS@aol.com >> >>Perhaps I missed out on something earlier, however in my airplanes you >>could >>"loose", or turn off, ALL of the electrical system, and continue to fly >>as >>long as the gas held out (during VFR). The engine runs off of a magneto >>thus >>supplying It's own power and doesn't need a battery, etc. >> >>Confused, >>Bill Byars >> >> >> >> > > No virus found in this outgoing message. > Checked by AVG Anti-Virus. > > > I am using the free version of SPAMfighter for private users. It has removed 721 spam emails to date. Paying users do not have this message in their emails. Try www.SPAMfighter.com for free now! ________________________________ Message 17 ____________________________________ Time: 04:54:52 PM PST US From: "Wayne Sweet" Subject: Re: AeroElectric-List: Re: 02/07/05 A Forced Landing --> AeroElectric-List message posted by: "Wayne Sweet" I second this super idea. Wayne ----- Original Message ----- From: "John Schroeder" Subject: Re: AeroElectric-List: Re: 02/07/05 A Forced Landing > --> AeroElectric-List message posted by: "John Schroeder" > > > On Thu, 17 Feb 2005 11:36:01 -0600, Robert L. Nuckolls, III > wrote: > >> One could easily craft a master caution/warning system >> that outputs a warning tone to the autio system in conjunction >> with the flashing light. > > Bob - > > Do you know if anyone in the OBAM community or a supplier thereof has done > such a system? I, for one, would love to have a kit available for an > annunciator panel that has both a master caution/warning lamp and an aural > output to the audio panel/intercomm. > > I suspect that there is something out there, but I have not heard of it. > Several of the EFIS systems have audio and visual cues when certain > systems mostly engine-related) go awry, but such things as baggage doors, > main doors, ground power hooked up, redundant oil pressure warning > circuitry, etc. could be worked into such a system. > > Thanks, > > John > > > -- > > > I am using the free version of SPAMfighter for private users. It has removed 721 spam emails to date. Paying users do not have this message in their emails. Try www.SPAMfighter.com for free now! ________________________________ Message 18 ____________________________________ Time: 05:59:17 PM PST US From: rv-9a-online Subject: Re: AeroElectric-List: P mags & urethane adhesive --> AeroElectric-List message posted by: rv-9a-online Rob, I don't know why your emails are bouncing, I'm getting them from other sources. Anyway, I didn't use Sika, I used 3m 5200 marine polyurethane bedding compound. I didn't use it for my canopy (slider), just rivets, although I may apply a fillet around certain areas later on. I built a slider, and I would do it again, although it has been the most painful part of the construction process. I've been working with other builders, and my summary is 'cut the aft bows!'. Most frames don't fit, and need to be cut&welded to fit properly. Vern do not archive Rob W M Shipley wrote: >--> AeroElectric-List message posted by: "Rob W M Shipley" > > This enquiry is for Vern Little since my message direct to you was bounced since your mail box is reported as full! >Your post on wiring the p-mags got me looking at your excellent web site and I noticed the use of the (?) Sika 295 to mount the temperature probe. I assume you used this for your canopy. Did you build a tipper or a slider and do you have any caveats to share since I plan on doing this with my tipper.. >Rob >Rob W M Shipley >N919RV (res) Fuselage .....still! >La Mesa, CA. (next to San Diego) >P.S. I own an autoglass company and am familiar with the technical requirements of this class of adhesives. >Do not archive. >No virus found in this outgoing message. >Checked by AVG Anti-Virus. > > > > ________________________________ Message 19 ____________________________________ Time: 11:39:18 PM PST US From: Frank & Dorothy Subject: Re: AeroElectric-List: Re: 02/07/05 A Forced Landing --> AeroElectric-List message posted by: Frank & Dorothy --> AeroElectric-List message posted by: "George Braly" >A recent visit with the FAA reveals they are opposed to "flashing" warning or caution lights. > >They claim it is too easy to dismiss them as being simply "faulty" lights. > > Seems unlikely to me... a faulty light might flicker at a high frequency, or turn on/off intermittently, but I've never seen one that blinks continuously at (say) 10Hz with an exact 50/50 duty cycle. Frank