---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 06/10/13: 13 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 06:29 AM - Re: Indicator light circuit with push to test (Eric M. Jones) 2. 07:34 AM - Re: Re: Indicator light circuit with push to test (Robert L. Nuckolls, III) 3. 09:24 AM - Re: Re: Indicator light circuit with push to test (John Grosse) 4. 01:00 PM - Re: Re: Indicator light circuit with push to test (Graeme Hart) 5. 01:39 PM - Re: Re: Indicator light circuit with push to test (John Grosse) 6. 02:04 PM - Re: Re: Indicator light circuit with push to test (Robert L. Nuckolls, III) 7. 02:17 PM - Re: Re: Indicator light circuit with push to test (Robert L. Nuckolls, III) 8. 02:25 PM - Re: Re: Indicator light circuit with push to test (Endspeed) 9. 03:04 PM - Re: Re: Indicator light circuit with push to test (Graeme Hart) 10. 03:32 PM - Re: Re: Indicator light circuit with push to test (Robert L. Nuckolls, III) 11. 05:38 PM - Re: Re: Indicator light circuit with push to test (Vern Little) 12. 06:23 PM - 12V Batteries (Mark Banus) 13. 07:11 PM - Re: 12V Batteries (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 06:29:44 AM PST US Subject: AeroElectric-List: Re: Indicator light circuit with push to test From: "Eric M. Jones" The really weird thing with using LEDs is that they will last longer than the socket, longer than the switch and longer than the airframe. So unless you're going full-on Steam Punk, or the press-to-test feature really does something useful, just remove the switch and put a cork in the hole. -------- Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge, MA 01550 (508) 764-2072 emjones(at)charter.net Read this topic online here: http://forums.matronics.com/viewtopic.php?p=402389#402389 ________________________________ Message 2 _____________________________________ Time: 07:34:33 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Indicator light circuit with push to test At 08:28 AM 6/10/2013, you wrote: > >The really weird thing with using LEDs is that they will last longer >than the socket, longer than the switch and longer than the >airframe. So unless you're going full-on Steam Punk, or the >press-to-test feature really does something useful, just remove the >switch and put a cork in the hole. Does the PTT button for a lamp/socket/switch combination not produce a false sense of security? That's sorta like going out on a high risk hike in the woods having only checked to see that your sandwiches are packed. We don't fly indicator lamps, switches, propellers or aileron control cables. These are all ingredients that go into recipes for a flight system .. Failure of any single ingredient to perform needs to be evaluated for potential impact on the system/mission . . . i.e. risks. One assumes that warning lights are included to mitigate risk. If the light is important enough to give it panel space and attention at pre-flight, is it not equally (if not more) critical to test that warning system end-to-end? Is it not better to test a warning system by watching for annunciation of a real stimulus like low pressure, unlocked canopy or low voltage . . . as opposed to knowing that the lamp is good? Bob . . . ________________________________ Message 3 _____________________________________ Time: 09:24:10 AM PST US From: John Grosse Subject: Re: AeroElectric-List: Re: Indicator light circuit with push to test That is certainly true, but if my landing gear "down light" doesn't come on, I'd like to be able to at least verify that the bulb is or isn't working. John Grosse > Robert L. Nuckolls, III > June 11, 2013 9:33 AM > > > > Is it not better to test a warning system by > watching for annunciation of a real stimulus > like low pressure, unlocked canopy or low > voltage . . . as opposed to knowing that the > lamp is good? > > > Bob . . . > ________________________________ Message 4 _____________________________________ Time: 01:00:37 PM PST US Subject: Re: AeroElectric-List: Re: Indicator light circuit with push to test From: Graeme Hart If you are sitting in the plane on the ground doing pre-flight checks I hope you would notice if the landing gear was not down! ;) On Tue, Jun 11, 2013 at 4:23 AM, John Grosse wrote: > grosseair@comcast.net> > > That is certainly true, but if my landing gear "down light" doesn't come > on, I'd like to be able to at least verify that the bulb is or isn't > working. > > John Grosse > > Robert L. Nuckolls, III >> > >> June 11, 2013 9:33 AM >> >> nuckolls.bob@aeroelectric.com**> >> >> >> Is it not better to test a warning system by >> watching for annunciation of a real stimulus >> like low pressure, unlocked canopy or low >> voltage . . . as opposed to knowing that the >> lamp is good? >> >> >> Bob . . . >> >> > > ________________________________ Message 5 _____________________________________ Time: 01:39:48 PM PST US From: John Grosse Subject: Re: AeroElectric-List: Re: Indicator light circuit with push to test Gee, really? The situation I was imagining would be in the air, on approach, but on the ground you would be right:) Do you happen to remember Eastern 401 that crashed in the Everglades while the crew tried to figure out if the gear light was burned out. A "push to test" function would have been handy to have. John Graeme Hart wrote: > > If you are sitting in the plane on the ground doing pre-flight checks > I hope you would notice if the landing gear was not down! ;) > > > On Tue, Jun 11, 2013 at 4:23 AM, John Grosse > wrote: > > > > > That is certainly true, but if my landing gear "down light" > doesn't come on, I'd like to be able to at least verify that the > bulb is or isn't working. > > John Grosse > ________________________________ Message 6 _____________________________________ Time: 02:04:09 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Indicator light circuit with push to test At 11:23 AM 6/10/2013, you wrote: > >That is certainly true, but if my landing gear "down light" doesn't >come on, I'd like to be able to at least verify that the bulb is or >isn't working. What difference would it make? During pre-flight, if you have ANY light producing an unexpected display, what do you do about it? Now we've moved from a systems integrity verification mode (pre-flight) to a diagnostic mode (not going flying right now). Pressing a button to show that it lights up doesn't change the realities of the next move. Bob . . . ________________________________ Message 7 _____________________________________ Time: 02:17:32 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Indicator light circuit with push to test At 03:39 PM 6/10/2013, you wrote: > >Gee, really? The situation I was imagining would be in the air, on >approach, but on the ground you would be right:) > >Do you happen to remember Eastern 401 that crashed in the Everglades >while the crew tried to figure out if the gear light was burned out. >A "push to test" function would have been handy to have. They DID have a PTT function that didn't light the light. So they were borrowing a lamp from another fixture. These can be changed without tools but it does involve 'fiddling' with the little flanged base lamps common to this style of backlit, sunlight viewable fixture. [] Whoever was supposed to be flying got so involved in diagnosis and in-flight maintenance issues that a shift in a/p from altitude hold to control wheel steering went unnoticed. This wasn't a case of not having a 'handy' feature, it was a breakdown of cockpit protocol. Bob . . . ________________________________ Message 8 _____________________________________ Time: 02:25:33 PM PST US Subject: Re: AeroElectric-List: Re: Indicator light circuit with push to test From: Endspeed Or maybe the simpler solution is two juxtaposed indicator bulbs wired in parallel. On Jun 10, 2013, at 3:39 PM, John Grosse wrote: > > Gee, really? The situation I was imagining would be in the air, on approach, but on the ground you would be right:) > > Do you happen to remember Eastern 401 that crashed in the Everglades while the crew tried to figure out if the gear light was burned out. A "push to test" function would have been handy to have. > > John > > Graeme Hart wrote: >> >> If you are sitting in the plane on the ground doing pre-flight checks I hope you would notice if the landing gear was not down! ;) >> >> >> >> On Tue, Jun 11, 2013 at 4:23 AM, John Grosse > wrote: >> >> > >> >> That is certainly true, but if my landing gear "down light" >> doesn't come on, I'd like to be able to at least verify that the >> bulb is or isn't working. >> >> John Grosse > > > > ________________________________ Message 9 _____________________________________ Time: 03:04:17 PM PST US Subject: Re: AeroElectric-List: Re: Indicator light circuit with push to test From: Graeme Hart Good point, we were obviously thinking of quite different situations. With an LED "light" the chance of it failing is minute. It is much more likely the sensor on the gear or the wiring will fail and a "push to test" function would do nothing to help in this situation. On Tue, Jun 11, 2013 at 8:39 AM, John Grosse wrote: > grosseair@comcast.net> > > Gee, really? The situation I was imagining would be in the air, on > approach, but on the ground you would be right:) > > Do you happen to remember Eastern 401 that crashed in the Everglades while > the crew tried to figure out if the gear light was burned out. A "push to > test" function would have been handy to have. > > John > > Graeme Hart wrote: > >> >> If you are sitting in the plane on the ground doing pre-flight checks I >> hope you would notice if the landing gear was not down! ;) >> >> >> >> On Tue, Jun 11, 2013 at 4:23 AM, John Grosse > grosseair@comcast.net>**> wrote: >> >> **> >> >> >> That is certainly true, but if my landing gear "down light" >> doesn't come on, I'd like to be able to at least verify that the >> bulb is or isn't working. >> >> John Grosse >> >> > > ________________________________ Message 10 ____________________________________ Time: 03:32:41 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: Indicator light circuit with push to test At 04:24 PM 6/10/2013, you wrote: > >Or maybe the simpler solution is two juxtaposed indicator bulbs >wired in parallel. Actually, there are sunlight viewable, dead-front annunciator fixtures that mount two bulbs in parallel. The idea is that the fixture still performs its intended function with only one lamp . . . but with obvious gradient of brightness across the face. The likelihood of loosing two lamps on any one flight cycle is very remote. All of the LED sunlight viewable fixtures I've encountered have multiple lamps . . . mostly to get the light required total light output and sufficient coverage of the back of the lens. These too would 'fail gracefully' if single lamps were to fail. But again, press-to-test verification of lamp functionality offers only a meager fraction of the information that a pilot would really like to have when making important decisions. Bob . . . ________________________________ Message 11 ____________________________________ Time: 05:38:51 PM PST US From: "Vern Little" Subject: Re: AeroElectric-List: Re: Indicator light circuit with push to test I think there is a bit of focus on testing the lamps. It=99s not the only function for the PTT function. I use the PTT to set the dimmer level for night operations. Press the button, dial in the light level you want and you won=99t be dazzled when a warning lamp comes on. Vern From: Graeme Hart Sent: Monday, June 10, 2013 3:03 PM Subject: Re: AeroElectric-List: Re: Indicator light circuit with push to test Good point, we were obviously thinking of quite different situations. With an LED "light" the chance of it failing is minute. It is much more likely the sensor on the gear or the wiring will fail and a "push to test" function would do nothing to help in this situation. On Tue, Jun 11, 2013 at 8:39 AM, John Grosse wrote: Gee, really? The situation I was imagining would be in the air, on approach, but on the ground you would be right:) Do you happen to remember Eastern 401 that crashed in the Everglades while the crew tried to figure out if the gear light was burned out. A "push to test" function would have been handy to have. John Graeme Hart wrote: If you are sitting in the plane on the ground doing pre-flight checks I hope you would notice if the landing gear was not down! ;) On Tue, Jun 11, 2013 at 4:23 AM, John Grosse > wrote: > That is certainly true, but if my landing gear "down light" doesn't come on, I'd like to be able to at least verify that the bulb is or isn't working. John Grosse ================= _ities such as List Un/Subscription, www.matronics.com/Navigator?AeroElectric-List" target="_blank">http://www.matronics.com/Navigator?AeroElectric-List ======================ttp://f orums.matronics.com/" target="_blank">http://forums.matronics.com ====================== -Matt Dralle, List Admin. ====== No virus found in this message. Checked by AVG - www.avg.com 06/10/13 ________________________________ Message 12 ____________________________________ Time: 06:23:10 PM PST US From: Mark Banus Subject: AeroElectric-List: 12V Batteries Bob, Several years ago I believe you were recommending Panasonic 1220 batteries, VRLA technology. I am also looking at the Odyssey PC 625/680 series with AGM technology. What is your choice for an all-electric aircraft? Thanks Mark Banus Glasair II FT ________________________________ Message 13 ____________________________________ Time: 07:11:11 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: 12V Batteries At 08:22 PM 6/10/2013, you wrote: >Bob, Several years ago I believe you were recommending Panasonic >1220 batteries, VRLA technology. I am also looking at the Odyssey >PC 625/680 series with AGM technology. What is your choice for an >all-electric aircraft? >Thanks >Mark Banus >Glasair II FT What engine and which architecture? 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