---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Mon 11/15/04: 29 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:01 AM - Re: [Bulk] Re: 406 Mhz GPS ELT For whom? (Jim Jewell) 2. 12:02 AM - Re: AW: Rotax 914, dual alt (manuel bonniot) 3. 03:15 AM - List Fund Raiser - New Gift Addition! (Matt Dralle) 4. 05:50 AM - Master Switch Question (Tinne maha) 5. 06:01 AM - Re: 406 Mhz GPS ELT (Glen Matejcek) 6. 06:22 AM - Re: Master Switch Question (Robert L. Nuckolls, III) 7. 06:24 AM - Re: Shunt with essential bus (Robert L. Nuckolls, III) 8. 06:33 AM - Re: Re: 406 Mhz GPS ELT (echristley@nc.rr.com) 9. 07:14 AM - LVWM questions (Gilles Thesee) 10. 09:13 AM - Re: LVWM questions (Robert L. Nuckolls, III) 11. 09:30 AM - Re: Shunt with essential bus (Mitch Faatz) 12. 09:44 AM - Re: List Fund Raiser - New Gift Addition! (William J. Applegate) 13. 10:04 AM - Re: [Bulk] Re: 406 Mhz GPS ELT For whom? (richard dudley) 14. 10:18 AM - Re: Keep warm circuit for Landing/Taxi lights (Dan Checkoway) 15. 10:34 AM - Re: LVWM questions (Gilles Thesee) 16. 10:51 AM - Re: AOA was Stall Horn (Brian Lloyd) 17. 11:26 AM - Re: AOA (Olivier Le Carbonnier) 18. 12:00 PM - Re: ELT Access (Robert L. Nuckolls, III) 19. 01:31 PM - Battery ground? (Robert L. Nuckolls, III) 20. 01:40 PM - Re: Shunt with essential bus (Robert L. Nuckolls, III) 21. 01:42 PM - Re: List Fund Raiser - New Gift Addition! (Robert L. Nuckolls, III) 22. 02:36 PM - Re: Battery ground? (Mickey Coggins) 23. 03:26 PM - Re: Keep warm circuit for Landing/Taxi lights (Eric M. Jones) 24. 04:39 PM - Re: AOA was Stall Horn (Paul Messinger) 25. 05:58 PM - AOA Comments (EMAproducts@aol.com) 26. 06:44 PM - Re: Keep warm circuit for Landing/Taxi lights (glaesers) 27. 06:58 PM - Two Grounds? (Tinne maha) 28. 07:30 PM - Re: Re: Keep warm circuit for Landing/Taxi lights (Richard E. Tasker) 29. 11:05 PM - ELTs/SAR (DEAN PSIROPOULOS) ________________________________ Message 1 _____________________________________ Time: 12:01:52 AM PST US From: "Jim Jewell" Subject: Re: AeroElectric-List: [Bulk] RE: 406 Mhz GPS ELT For whom? --> AeroElectric-List message posted by: "Jim Jewell" For whom are we buying and installing the "approved"or not 406 MHz GPS ELT, the 121.5 ELT or what have you? Be it a simple piece of a mirror, a 406 MHz GPS ELT a 121.5 ELT or what have you? The `more' effective the device is in bringing survivor(s) or the remains thereof safely back from the edge of life and death, the `less' risk, time, and money will be invested by all the souls that play a roll in carrying out the search, rescue and recovery. Those of us that consciously venture closer to the "edge" usually know at least something about the risk to ourselves. We should also be aware of the consequences and risks our various adventures gone wrong will have on others. Like it or not, our actions can unnecessarily negatively effect the Safety health wealth and happiness of an often surprisingly large number of people should things go sour. Piloting a privately owned aircraft, boat, skiing or boarding out of bounds or for that matter any other activity that removes us from our accepted communication systems and on demand contact with our homes and peer group thereby brings us just that much closer to the "edge". I'm suggesting here that should we choose to partake in activities that have the potential to leave us at the "edge" waiting and hoping that others will take it upon themselves to risk life and limb on our behalf, we owe it to them to equip ourselves with what ever information planning and alerting devices we can reasonably afford and utilize that will effectively reduce the loss and risk factors for all. The fact is that whether or not we take others into consideration when we decide to go off in search of adventure, almost invariably they will be involved when the crap hits the fan. The now lowly appreciated and often bad mouthed ELT at one time represented a break through in safety technology. It most certainly has saved many lives of both the survivors and those called upon to be their rescuers. I am inclined therefore to say that the answer to the opening question is; Whether we think about it or not the purpose of emergency locators no matter what type, are intended for the benefit of all the parties potentially involved, not just for our individual selves. Whether buying a maximum affordable minimum requirement unit or spending for the best technology doodad available, I hope the above considerations help soften the blow when the time comes to offer up the cash. I to hope that the prices for the "approved 406" go down as production ramps up. I also look forward to the day that the electronics for this gets so small that it might become an integral part of every cell and satellite phone for example. Great flights and greased landings Jim in Kelowna _-===================================================================== _-_-= -- Please Support Your Lists This Month -- _-= (And Get Some AWESOME FREE Gifts!) _-_-= November is the Annual List Fund Raiser. Click on the _-= Contribution link below to find out more about this _-= year's Terrific Free Incentive Gifts provided by the _-= The Builder's Bookstore www.buildersbooks.com! _-_-= List Contribution Web Site _-_-= http://www.matronics.com/contribution _-_-= Thank you for your generous support! _-= -Matt Dralle, List Admin. _-_-===================================================================== _-= - The AeroElectric-List Email Forum - _-= This forum is sponsored entirely through the Contributions _-= of List members. You'll never see banner ads or any other _-= form of direct advertising on the Matronics Forums. _-===================================================================== _-= List Related Information _-= Post Message: aeroelectric-list@matronics.com _-= UN/SUBSCRIBE: http://www.matronics.com/subscription _-= List FAQ: http://www.matronics.com/FAQ/AeroElectric-List.htm _-= Search Engine: http://www.matronics.com/search _-= 7-Day Browse: http://www.matronics.com/browse/aeroelectric-list _-= Browse Digests: http://www.matronics.com/digest/aeroelectric-list _-= Live List Chat: http://www.matronics.com/chat _-= Archives: http://www.matronics.com/archives _-= Photo Share: http://www.matronics.com/photoshare _-= List Specific: http://www.matronics.com/aeroelectric-list _-= Other Lists: http://www.matronics.com/emaillists _-= Trouble Report http://www.matronics.com/trouble-report _-= Contributions: http://www.matronics.com/contribution _-===================================================================== ________________________________ Message 2 _____________________________________ Time: 12:02:07 AM PST US From: "manuel bonniot" Subject: Re: AW: AeroElectric-List: Rotax 914, dual alt --> AeroElectric-List message posted by: "manuel bonniot" Hi Bob I mesured everything and it really seems the SD20 can fit the Rotax. About Amps, if I refer to the performance data for the SD20 on B&C website, it produces 18 A/14V at 2500 RPM, and 22 A at 3000 RPM. So, do I misread the figures ? Manuel >From: "Robert L. Nuckolls, III" >Reply-To: aeroelectric-list@matronics.com >To: aeroelectric-list@matronics.com >Subject: Re: AW: AeroElectric-List: Rotax 914, dual alt >Date: Sun, 14 Nov 2004 15:05:35 -0600 > >--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > >At 12:16 PM 11/14/2004 +0100, you wrote: > >--> AeroElectric-List message posted by: "Europa (Alfred Buess)" > > > > > >Manuel, > > > >The electrical system of my Europa XS (not yet flying) with a Rotax 912S > >is based on two alternators working in parallel if the power consumtion > >needs it. The setpoint of the regulator for the Rotax alternator is set > >at 14.3 V, the setpoint of the regulator for the vacuum drive pad > >alternator (a SD-8 in my case) is set at 13.8 V. If the power > >consumption exceeds the output of the Rotax alternator, the bus voltage > >will fall below 14.3 V and at 13.8 V the SD-8 will come alive. This > >means the SD-8 works more like a boost alternator than an emergency > >alternator. If you are interested, I could send you a CAD-file (.dwg) of > >my electrical system. > > > >Alfred > > To my knowledge, there are no vacuum-pump, pad-driven alternators > that will produce useful amounts of snort on the 912/914 series > engines. Their pads are just too slow. Didn't somebody on the list > point us to a successful belt driven add-on to the Rotax in a Europa? > I seem to recall having seen photos. > > > >I am working on a Dyn Aero MCR 4S, to be equipped for IFR flying (ad-hoc > > > >avionics, pitot heat...), powered by a Rotax 914 (electrically > >dependant). I know the Rotax alt won't deliver enough power for all my > >stuff. So I need > >to add a second alternator. I don't have enough room in the cowling to > >put a > >belt driven one, so my only reasonable option is the SD 20. With the > >vacuum > >pump pad turning at 0.54 the engine rpm, it could nearly deliver 20 amp > >at > >5200 RPM, which is not so bad. > > This puts your pad at which is 2800. The pad on a lycoming or > continental runs at 1.25 to 1.4 of crankshaft which is about > 3200 RPM where the SD-20 is rated. Further, I'm not sure the > SD-20 fits the Rotax. > > Have you discussed this with B&C? > > Bob . . . > > >_-===================================================================== >_->_-= -- Please Support Your Lists This Month -- >_-= (And Get Some AWESOME FREE Gifts!) >_->_-= November is the Annual List Fund Raiser. 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Click on the _-= Contribution link below to find out more about this _-= year's Terrific Free Incentive Gifts provided by the _-= The Builder's Bookstore www.buildersbooks.com! _-_-= List Contribution Web Site _-_-= http://www.matronics.com/contribution _-_-= Thank you for your generous support! _-= -Matt Dralle, List Admin. _-_-===================================================================== _-= - The AeroElectric-List Email Forum - _-= This forum is sponsored entirely through the Contributions _-= of List members. You'll never see banner ads or any other _-= form of direct advertising on the Matronics Forums. _-===================================================================== _-= List Related Information _-= Post Message: aeroelectric-list@matronics.com _-= UN/SUBSCRIBE: http://www.matronics.com/subscription _-= List FAQ: http://www.matronics.com/FAQ/AeroElectric-List.htm _-= Search Engine: http://www.matronics.com/search _-= 7-Day Browse: http://www.matronics.com/browse/aeroelectric-list _-= Browse Digests: http://www.matronics.com/digest/aeroelectric-list _-= Live List Chat: http://www.matronics.com/chat _-= Archives: http://www.matronics.com/archives _-= Photo Share: http://www.matronics.com/photoshare _-= List Specific: http://www.matronics.com/aeroelectric-list _-= Other Lists: http://www.matronics.com/emaillists _-= Trouble Report http://www.matronics.com/trouble-report _-= Contributions: http://www.matronics.com/contribution _-===================================================================== ________________________________ Message 3 _____________________________________ Time: 03:15:41 AM PST US From: Matt Dralle Subject: AeroElectric-List: List Fund Raiser - New Gift Addition! --> AeroElectric-List message posted by: Matt Dralle Dear Listers, Paul Besing of Aeroware Enterprises (www.kitlog.com) has generously contributed free registered copies of his great Windows kit logging software called Kitlog Pro to support this year's List Fund Raiser! Beginning on November 13, anyone making a List Contribution of $50 or more will qualify to receive the Windows web site download distribution of Kitlog Pro along with an official registration number via email on December 5th. The offer will continue through the end of the Fund Raiser. I want to thank Andy Gold (www.buildersbooks.com) and Paul Besing for their generous contributions in support of the Matronics Email Lists this year! Won't you take a minute and support these Lists as well? It is exclusively your contributions that enable the continue operation and upgrade of these Lists. The SSL Secure web site for making your Contribution can be found here: http://www.matronics.com/contribution Thank you! Matt Dralle Matronics Email List Administrator Matt G Dralle | Matronics | PO Box 347 | Livermore | CA | 94551 925-606-1001 V | 925-606-6281 F | dralle@matronics.com Email http://www.matronics.com/ WWW | Featuring Products For Aircraft do not archive _-===================================================================== _-_-= -- Please Support Your Lists This Month -- _-= (And Get Some AWESOME FREE Gifts!) _-_-= November is the Annual List Fund Raiser. Click on the _-= Contribution link below to find out more about this _-= year's Terrific Free Incentive Gifts provided by the _-= The Builder's Bookstore www.buildersbooks.com! _-_-= List Contribution Web Site _-_-= http://www.matronics.com/contribution _-_-= Thank you for your generous support! _-= -Matt Dralle, List Admin. _-_-===================================================================== _-= - The AeroElectric-List Email Forum - _-= This forum is sponsored entirely through the Contributions _-= of List members. You'll never see banner ads or any other _-= form of direct advertising on the Matronics Forums. _-===================================================================== _-= List Related Information _-= Post Message: aeroelectric-list@matronics.com _-= UN/SUBSCRIBE: http://www.matronics.com/subscription _-= List FAQ: http://www.matronics.com/FAQ/AeroElectric-List.htm _-= Search Engine: http://www.matronics.com/search _-= 7-Day Browse: http://www.matronics.com/browse/aeroelectric-list _-= Browse Digests: http://www.matronics.com/digest/aeroelectric-list _-= Live List Chat: http://www.matronics.com/chat _-= Archives: http://www.matronics.com/archives _-= Photo Share: http://www.matronics.com/photoshare _-= List Specific: http://www.matronics.com/aeroelectric-list _-= Other Lists: http://www.matronics.com/emaillists _-= Trouble Report http://www.matronics.com/trouble-report _-= Contributions: http://www.matronics.com/contribution _-===================================================================== ________________________________ Message 4 _____________________________________ Time: 05:50:02 AM PST US From: "Tinne maha" Subject: AeroElectric-List: Master Switch Question --> AeroElectric-List message posted by: "Tinne maha" Listers, Here is an archived post that is a perfect segueway to my question: Bob/Others I am confused and need help. In Figure Z-13 (utilizing SD-8 alternator) the DC power master switch is a 2-10. In Figure Z-12 (utilizing SD-20 alternator) the DC power master switch is a 2-3. Why the difference? Is it that with the 2-10 switch the engine is to be started with this switch in the center position? Is it that with the 2-10 switch the regulator can be disconnected from the bus for some reason, perhaps testing? The reason I am asking is I initially planned to install the SD-8 alternator and wired my panel accordingly (Figure Z-13) with the 2-10 master power switch. I have since decided to install the SD-20 which takes me to Figure Z-12 which calls for a 2-3 master power switch. Is it important that I cha nge out my 2-10 master power switch with a 2-3 switch? If not, what is the purpose for the center position on the 2-10 switch? A little help would be appreciated. Thanks. Pete Hunt Clearwater, FL RV-6, Wiring I not sure if this will help you but, I do know that with a 2-10 switch the center is for the battery and the top for the alternator. Close but it's a little more complicated than that. Alternators generally do not run well without also having a battery on line. Early electrified aircraft used generators which would come on line and deliver useful, relatively clean energy without a battery. When generators were removed from certified ships and replaced with alternators, powers-that-be deduced a need to make sure that an alternator could not be left on-line without the battery . . . and that the battery was on-line before the alternator was brought up. This design philosophy gave birth to the infamous "split rocker" master switch that has been part-and-parcel of the majority of single engine aircraft architectures for nearly 40 years. I've seen many OBAM aircraft where the builder wanted to use some whippy looking switches on the panel but had a Cesssna style split rocker switch enshrined in a place of honor. The 2-10, progressive transfer switch can provide the same action without having to resort to th e over-priced split rocker. The 2-10 looks like its brothers and cousins and mounts in the same nice round hole. Full down turns both battery -AND- alternator OFF. Mid position turns only the battery ON. Upper position leaves the battery ON and turns the alternator ON too. If one doesn't want to spend the dollars and take the time to label a three-position, progressive transfer 2-10 switch, the 2-3 is a completely acceptable substitute. In this case, battery and alternator are brought on and off together . . . an entirely satisfactory mode of operation also. When one uses a pullable breaker for the crowbar OV protection, there's a panel mounted control that permits an alternator to be taken off line for battery only ground operations (usually for maintenance) -OR- to take the alternator off line should it become unstable in flight. If it were my airplane, I'd probably use a 2-3 switch. It's inexpensive and spares can be acquired from lots of sources. Bob . . . What is the advantage of running the alternator field wire (main bus to pullable breaker to 6 on LR3C) through a double pole switch? Wouldn't it be equivalent to use a 1-3 switch for the battery master pull the breaker for the few times you want to go battery only? Alternatively, wouldn't it also be equivalent to use the 2-10 switch skip the pullable breaker? Maybe I'm misunderstanding the difference between switches breakers. Please help. Thanks, Grant _-===================================================================== _-_-= -- Please Support Your Lists This Month -- _-= (And Get Some AWESOME FREE Gifts!) _-_-= November is the Annual List Fund Raiser. Click on the _-= Contribution link below to find out more about this _-= year's Terrific Free Incentive Gifts provided by the _-= The Builder's Bookstore www.buildersbooks.com! _-_-= List Contribution Web Site _-_-= http://www.matronics.com/contribution _-_-= Thank you for your generous support! _-= -Matt Dralle, List Admin. _-_-===================================================================== _-= - The AeroElectric-List Email Forum - _-= This forum is sponsored entirely through the Contributions _-= of List members. You'll never see banner ads or any other _-= form of direct advertising on the Matronics Forums. _-===================================================================== _-= List Related Information _-= Post Message: aeroelectric-list@matronics.com _-= UN/SUBSCRIBE: http://www.matronics.com/subscription _-= List FAQ: http://www.matronics.com/FAQ/AeroElectric-List.htm _-= Search Engine: http://www.matronics.com/search _-= 7-Day Browse: http://www.matronics.com/browse/aeroelectric-list _-= Browse Digests: http://www.matronics.com/digest/aeroelectric-list _-= Live List Chat: http://www.matronics.com/chat _-= Archives: http://www.matronics.com/archives _-= Photo Share: http://www.matronics.com/photoshare _-= List Specific: http://www.matronics.com/aeroelectric-list _-= Other Lists: http://www.matronics.com/emaillists _-= Trouble Report http://www.matronics.com/trouble-report _-= Contributions: http://www.matronics.com/contribution _-===================================================================== ________________________________ Message 5 _____________________________________ Time: 06:01:00 AM PST US From: "Glen Matejcek" Subject: AeroElectric-List: RE: 406 Mhz GPS ELT --> AeroElectric-List message posted by: "Glen Matejcek" Hi All- A couple of data points: That panel mounted ELT switch can of course be used to start the ELT up before the impact, if one knows the impact is coming. More important though is the cell phone issue. I accidentally discovered (no, I never read the manual) that my Nokia cell phone has GPS. If I wander down the correct menu, it asks if I want the phone to make my GPS position available ALL THE TIME (as in even when I'm not using the phone!!!!) or only when calling 911. WOW! Great safety feature, and quite handy for big brother. This, combined with the fact that PCS phones will work airborne as long as you're not too high, is a great advantage for us aviators. If you're going down in the wild, just dial 911 and your position will be known to someone in the PCS world, if you are in range of a ground station. If you can talk to the operator and convince them it's not a prank call, help should be on the way immediately. Another data point is that my EFIS will have a continuous lat/long readout displayed. One could broadcast that on the way down to jump start SAR. FWIW- Glen Matejcek aerobubba@earthlink.net _-===================================================================== _-_-= -- Please Support Your Lists This Month -- _-= (And Get Some AWESOME FREE Gifts!) _-_-= November is the Annual List Fund Raiser. Click on the _-= Contribution link below to find out more about this _-= year's Terrific Free Incentive Gifts provided by the _-= The Builder's Bookstore www.buildersbooks.com! _-_-= List Contribution Web Site _-_-= http://www.matronics.com/contribution _-_-= Thank you for your generous support! _-= -Matt Dralle, List Admin. _-_-===================================================================== _-= - The AeroElectric-List Email Forum - _-= This forum is sponsored entirely through the Contributions _-= of List members. You'll never see banner ads or any other _-= form of direct advertising on the Matronics Forums. _-===================================================================== _-= List Related Information _-= Post Message: aeroelectric-list@matronics.com _-= UN/SUBSCRIBE: http://www.matronics.com/subscription _-= List FAQ: http://www.matronics.com/FAQ/AeroElectric-List.htm _-= Search Engine: http://www.matronics.com/search _-= 7-Day Browse: http://www.matronics.com/browse/aeroelectric-list _-= Browse Digests: http://www.matronics.com/digest/aeroelectric-list _-= Live List Chat: http://www.matronics.com/chat _-= Archives: http://www.matronics.com/archives _-= Photo Share: http://www.matronics.com/photoshare _-= List Specific: http://www.matronics.com/aeroelectric-list _-= Other Lists: http://www.matronics.com/emaillists _-= Trouble Report http://www.matronics.com/trouble-report _-= Contributions: http://www.matronics.com/contribution _-===================================================================== ________________________________ Message 6 _____________________________________ Time: 06:22:12 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Master Switch Question --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 05:48 AM 11/15/2004 -0800, you wrote: >--> AeroElectric-List message posted by: "Tinne maha" > > >Listers, > > >Here is an archived post that is a perfect segueway to my question: > > >Bob/Others I am confused and need help. In Figure Z-13 (utilizing SD-8 >alternator) the DC power master switch is a 2-10. In Figure Z-12 >(utilizing SD-20 alternator) the DC power master switch is a 2-3. Why >the difference? Is it that with the 2-10 switch the engine is to be >started with this switch in the center position? Is it that with the 2-10 >switch the regulator can be disconnected from the bus for some reason, >perhaps testing? The reason I am asking is I initially planned to >install the SD-8 alternator and wired my panel accordingly (Figure Z-13) >with the 2-10 master power switch. I have since decided to install the >SD-20 which takes me to Figure Z-12 which calls for a 2-3 master power >switch. Is it important that I cha > nge out my 2-10 master power switch with a 2-3 switch? If not, what is > the purpose for the center position on the 2-10 switch? A little > help would be appreciated. Thanks. Pete Hunt Clearwater, FL RV-6, > Wiring I not sure if this will help you but, I do know that with a > 2-10 switch the center is for the battery and the top for the alternator. > >Close but it's a little more complicated than that. Alternators generally >do not run well without also having a battery on line. Early electrified >aircraft used generators which would come on line and deliver useful, >relatively clean energy without a battery. When generators were removed >from certified ships and replaced with alternators, powers-that-be deduced >a need to make sure that an alternator could not be left on-line without >the battery . . . and that the battery was on-line before the alternator >was brought up. This design philosophy gave birth to the infamous "split >rocker" master switch that has been part-and-parcel of the majority of >single engine aircraft architectures for nearly 40 years. I've seen many >OBAM aircraft where the builder wanted to use some whippy looking switches >on the panel but had a Cesssna style split rocker switch enshrined in a >place of honor. The 2-10, progressive transfer switch can provide the same >action without having to resort to th > e over-priced split rocker. The 2-10 looks like its brothers and cousins > and mounts in the same nice round hole. Full down turns both battery > -AND- alternator OFF. Mid position turns only the battery ON. Upper > position leaves the battery ON and turns the alternator ON too. If one > doesn't want to spend the dollars and take the time to label a > three-position, progressive transfer 2-10 switch, the 2-3 is a completely > acceptable substitute. In this case, battery and alternator are brought > on and off together . . . an entirely satisfactory mode of operation > also. When one uses a pullable breaker for the crowbar OV protection, > there's a panel mounted control that permits an alternator to be taken > off line for battery only ground operations (usually for maintenance) > -OR- to take the alternator off line should it become unstable in flight. > If it were my airplane, I'd probably use a 2-3 switch. It's inexpensive > and spares can be acquired from lots of sources. > >Bob . . . > > >What is the advantage of running the alternator field wire (main bus to >pullable breaker to 6 on LR3C) through a double pole switch? Wouldn't it >be equivalent to use a 1-3 switch for the battery master pull the breaker >for the few times you want to go battery only? If you do as you've suggested, opening the Battery Master switch only with the engine running will not make the system shut down. The alternator will probably continue to run self-excited but with unpredictable performance. This is why the alternator/battery switch were combined into their current single two-pole switch configuration when generators (separate battery and generator switches) were taken off the airplane. In the Z-figures, when you turn the DC PWR MASTER switch OFF, the system goes completely dark at operation of the one switch and without risk of leaving an alternator on line after the battery is taken off. > Alternatively, wouldn't it also be equivalent to use the 2-10 > switch skip the pullable breaker? Sure, you still need the breaker if you're using the crowbar ov protection scheme but it need not be pullable. >Maybe I'm misunderstanding the difference between switches breakers. >Please help. Switches control things, breakers protect things. There are ways folks have attempted to combine their functions over the years but they are not cost or performance effective in the architectures depicted in Appendix Z. Bob . . . _-===================================================================== _-_-= -- Please Support Your Lists This Month -- _-= (And Get Some AWESOME FREE Gifts!) _-_-= November is the Annual List Fund Raiser. Click on the _-= Contribution link below to find out more about this _-= year's Terrific Free Incentive Gifts provided by the _-= The Builder's Bookstore www.buildersbooks.com! _-_-= List Contribution Web Site _-_-= http://www.matronics.com/contribution _-_-= Thank you for your generous support! _-= -Matt Dralle, List Admin. _-_-===================================================================== _-= - The AeroElectric-List Email Forum - _-= This forum is sponsored entirely through the Contributions _-= of List members. You'll never see banner ads or any other _-= form of direct advertising on the Matronics Forums. _-===================================================================== _-= List Related Information _-= Post Message: aeroelectric-list@matronics.com _-= UN/SUBSCRIBE: http://www.matronics.com/subscription _-= List FAQ: http://www.matronics.com/FAQ/AeroElectric-List.htm _-= Search Engine: http://www.matronics.com/search _-= 7-Day Browse: http://www.matronics.com/browse/aeroelectric-list _-= Browse Digests: http://www.matronics.com/digest/aeroelectric-list _-= Live List Chat: http://www.matronics.com/chat _-= Archives: http://www.matronics.com/archives _-= Photo Share: http://www.matronics.com/photoshare _-= List Specific: http://www.matronics.com/aeroelectric-list _-= Other Lists: http://www.matronics.com/emaillists _-= Trouble Report http://www.matronics.com/trouble-report _-= Contributions: http://www.matronics.com/contribution _-===================================================================== ________________________________ Message 7 _____________________________________ Time: 06:24:41 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Shunt with essential bus --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 09:19 PM 11/14/2004 -0800, you wrote: >--> AeroElectric-List message posted by: "Mitch Faatz" > > > When you put a loadmeter in the alternator b-lead, then it > > does exactly what you've asked for . . . total load on the > > system. ... > >Okay, so I'll put the shunt between the starter contactor and the >master/battery contactor and it will work perfectly except when the battery >contactor is shut off and the essential bus feed turned on, correct? No, that would run starter current through the shunt. All of the Z-figures suggest wiring ammeters as alternator loadmeters. Shunts in the b-lead of the alternator. What information do you perceive is not available to you with this configuration? Bob . . . _-===================================================================== _-_-= -- Please Support Your Lists This Month -- _-= (And Get Some AWESOME FREE Gifts!) _-_-= November is the Annual List Fund Raiser. Click on the _-= Contribution link below to find out more about this _-= year's Terrific Free Incentive Gifts provided by the _-= The Builder's Bookstore www.buildersbooks.com! _-_-= List Contribution Web Site _-_-= http://www.matronics.com/contribution _-_-= Thank you for your generous support! _-= -Matt Dralle, List Admin. _-_-===================================================================== _-= - The AeroElectric-List Email Forum - _-= This forum is sponsored entirely through the Contributions _-= of List members. You'll never see banner ads or any other _-= form of direct advertising on the Matronics Forums. _-===================================================================== _-= List Related Information _-= Post Message: aeroelectric-list@matronics.com _-= UN/SUBSCRIBE: http://www.matronics.com/subscription _-= List FAQ: http://www.matronics.com/FAQ/AeroElectric-List.htm _-= Search Engine: http://www.matronics.com/search _-= 7-Day Browse: http://www.matronics.com/browse/aeroelectric-list _-= Browse Digests: http://www.matronics.com/digest/aeroelectric-list _-= Live List Chat: http://www.matronics.com/chat _-= Archives: http://www.matronics.com/archives _-= Photo Share: http://www.matronics.com/photoshare _-= List Specific: http://www.matronics.com/aeroelectric-list _-= Other Lists: http://www.matronics.com/emaillists _-= Trouble Report http://www.matronics.com/trouble-report _-= Contributions: http://www.matronics.com/contribution _-===================================================================== ________________________________ Message 8 _____________________________________ Time: 06:33:03 AM PST US From: echristley@nc.rr.com Subject: Re: AeroElectric-List: RE: 406 Mhz GPS ELT --> AeroElectric-List message posted by: echristley@nc.rr.com > --> AeroElectric-List message posted by: "Glen Matejcek" > > Hi All- > I > accidentallydiscovered (no, I never read the manual) that my Nokia > cell phone has GPS. > If I wander down the correct menu, it asks if I want the phone to > make my > GPS position available ALL THE TIME (as in even when I'm not using the > phone!!!!) or only when calling 911. WOW! Great safety feature, > and quite > handy for big brother. All new cell phones sold in the US have this 'feature', again per federal law. I was pushed through under the guise of helping to find 911 callers, but I think it had more to do with finding drug traffickers (at least the ones smart enough not to set up a deal from their hotel room). _-===================================================================== _-_-= -- Please Support Your Lists This Month -- _-= (And Get Some AWESOME FREE Gifts!) _-_-= November is the Annual List Fund Raiser. Click on the _-= Contribution link below to find out more about this _-= year's Terrific Free Incentive Gifts provided by the _-= The Builder's Bookstore www.buildersbooks.com! _-_-= List Contribution Web Site _-_-= http://www.matronics.com/contribution _-_-= Thank you for your generous support! _-= -Matt Dralle, List Admin. _-_-===================================================================== _-= - The AeroElectric-List Email Forum - _-= This forum is sponsored entirely through the Contributions _-= of List members. You'll never see banner ads or any other _-= form of direct advertising on the Matronics Forums. _-===================================================================== _-= List Related Information _-= Post Message: aeroelectric-list@matronics.com _-= UN/SUBSCRIBE: http://www.matronics.com/subscription _-= List FAQ: http://www.matronics.com/FAQ/AeroElectric-List.htm _-= Search Engine: http://www.matronics.com/search _-= 7-Day Browse: http://www.matronics.com/browse/aeroelectric-list _-= Browse Digests: http://www.matronics.com/digest/aeroelectric-list _-= Live List Chat: http://www.matronics.com/chat _-= Archives: http://www.matronics.com/archives _-= Photo Share: http://www.matronics.com/photoshare _-= List Specific: http://www.matronics.com/aeroelectric-list _-= Other Lists: http://www.matronics.com/emaillists _-= Trouble Report http://www.matronics.com/trouble-report _-= Contributions: http://www.matronics.com/contribution _-===================================================================== ________________________________ Message 9 _____________________________________ Time: 07:14:54 AM PST US From: "Gilles Thesee" Subject: AeroElectric-List: LVWM questions --> AeroElectric-List message posted by: "Gilles Thesee" Hi Bob, This is just to ask if you received the diagrams I tried to send you, and if you had time to have a look at them. I know you're busy but I would really appreciate any hints as to how to conduct mmy investigations. Thanks, Regards, Gilles _-===================================================================== _-_-= -- Please Support Your Lists This Month -- _-= (And Get Some AWESOME FREE Gifts!) _-_-= November is the Annual List Fund Raiser. Click on the _-= Contribution link below to find out more about this _-= year's Terrific Free Incentive Gifts provided by the _-= The Builder's Bookstore www.buildersbooks.com! _-_-= List Contribution Web Site _-_-= http://www.matronics.com/contribution _-_-= Thank you for your generous support! _-= -Matt Dralle, List Admin. _-_-===================================================================== _-= - The AeroElectric-List Email Forum - _-= This forum is sponsored entirely through the Contributions _-= of List members. You'll never see banner ads or any other _-= form of direct advertising on the Matronics Forums. _-===================================================================== _-= List Related Information _-= Post Message: aeroelectric-list@matronics.com _-= UN/SUBSCRIBE: http://www.matronics.com/subscription _-= List FAQ: http://www.matronics.com/FAQ/AeroElectric-List.htm _-= Search Engine: http://www.matronics.com/search _-= 7-Day Browse: http://www.matronics.com/browse/aeroelectric-list _-= Browse Digests: http://www.matronics.com/digest/aeroelectric-list _-= Live List Chat: http://www.matronics.com/chat _-= Archives: http://www.matronics.com/archives _-= Photo Share: http://www.matronics.com/photoshare _-= List Specific: http://www.matronics.com/aeroelectric-list _-= Other Lists: http://www.matronics.com/emaillists _-= Trouble Report http://www.matronics.com/trouble-report _-= Contributions: http://www.matronics.com/contribution _-===================================================================== ________________________________ Message 10 ____________________________________ Time: 09:13:30 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: LVWM questions --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 04:12 PM 11/15/2004 +0100, you wrote: >--> AeroElectric-List message posted by: "Gilles Thesee" > > >Hi Bob, > >This is just to ask if you received the diagrams I tried to send you, and if >you had time to have a look at them. >I know you're busy but I would really appreciate any hints as to how to >conduct mmy investigations. Yes, I have them. REALLY preoccupied right now. Had to put my dad in the hospital last Wednesday and given that I'm executor of his estate and power of attorney on his business activities, it's pretty busy. I'll see if I can get to them this evening. Bob . . . ________________________________ Message 11 ____________________________________ Time: 09:30:31 AM PST US From: "Mitch Faatz" Subject: Re: AeroElectric-List: Shunt with essential bus --> AeroElectric-List message posted by: "Mitch Faatz" > No, that would run starter current through the shunt. All of the > Z-figures suggest wiring ammeters as alternator loadmeters. Shunts > in the b-lead of the alternator. ... Ah HA! That snapped something in my brain! I was looking at the ammeter as a general "battery load" meter instead of alternator load meter. So if the battery/alt switch is turned off and essential bus alternate feedpath is turned on: no feed to the alternator, ammeter will be zero but who cares because you're going to land and fix the problem. I wanted to use the ammeter as a "system load" meter so even if I was running essential bus only, I could still see the total load on the system and verify I'm running a reduce load on the battery. Mitch Faatz Auburn, CA RV-6A Finish Kit ________________________________ Message 12 ____________________________________ Time: 09:44:02 AM PST US From: "William J. Applegate" Subject: Re: AeroElectric-List: List Fund Raiser - New Gift Addition! --> AeroElectric-List message posted by: "William J. Applegate" Hi Matt, I kinda feel shortchanged. I donated more than $50 dollars last week and placed my donation just a few days before this offer started. Any chance I can get the free download? Thanks............Bill Applegate.....520-296-1502. Matt Dralle wrote: >--> AeroElectric-List message posted by: Matt Dralle > > >Dear Listers, > >Paul Besing of Aeroware Enterprises (www.kitlog.com) has generously >contributed free registered copies of his great Windows kit logging >software called Kitlog Pro to support this year's List Fund >Raiser! Beginning on November 13, anyone making a List Contribution of $50 >or more will qualify to receive the Windows web site download distribution >of Kitlog Pro along with an official registration number via email on >December 5th. The offer will continue through the end of the Fund Raiser. > >I want to thank Andy Gold (www.buildersbooks.com) and Paul Besing for their >generous contributions in support of the Matronics Email Lists this >year! Won't you take a minute and support these Lists as well? It is >exclusively your contributions that enable the continue operation and >upgrade of these Lists. The SSL Secure web site for making your >Contribution can be found here: > > http://www.matronics.com/contribution > >Thank you! > >Matt Dralle >Matronics Email List Administrator > > >Matt G Dralle | Matronics | PO Box 347 | Livermore | CA | 94551 >925-606-1001 V | 925-606-6281 F | dralle@matronics.com Email >http://www.matronics.com/ WWW | Featuring Products For Aircraft >do not archive > > > > ________________________________ Message 13 ____________________________________ Time: 10:04:05 AM PST US From: richard dudley Subject: Re: AeroElectric-List: [Bulk] RE: 406 Mhz GPS ELT For whom? --> AeroElectric-List message posted by: richard dudley Hi Jim, I must heartely agree with your comments. They apply in a generic way to all sorts of activities from mountain climbing to round-the-world sailors. The rescues so often risk the lives of the rescuers. Often the living on the edge-ers have not thought of that or take for granted that someone will rescue them if they get into trouble. Or that help is only a cellphone call away. Regards, Richard Dudley Jim Jewell wrote: >--> AeroElectric-List message posted by: "Jim Jewell" > >For whom are we buying and installing the "approved"or not 406 MHz GPS ELT, >the 121.5 ELT or what have you? > >Be it a simple piece of a mirror, a 406 MHz GPS ELT a 121.5 ELT or what have >you? The `more' effective the device is in bringing survivor(s) or the >remains thereof safely back from the edge of life and death, the `less' >risk, time, and money will be invested by all the souls that play a roll in >carrying out the search, rescue and recovery. >Those of us that consciously venture closer to the "edge" usually know at >least something about the risk to ourselves. We should also be aware of the >consequences and risks our various adventures gone wrong will have on >others. Like it or not, our actions can unnecessarily negatively effect the >Safety health wealth and happiness of an often surprisingly large number of >people should things go sour. > >Piloting a privately owned aircraft, boat, skiing or boarding out of bounds >or for that matter any other activity that removes us from our accepted >communication systems and on demand contact with our homes and peer group >thereby brings us just that much closer to the "edge". > >I'm suggesting here that should we choose to partake in activities that have >the potential to leave us at the "edge" waiting and hoping that others will >take it upon themselves to risk life and limb on our behalf, we owe it to >them to equip ourselves with what ever information planning and alerting >devices we can reasonably afford and utilize that will effectively reduce >the loss and risk factors for all. >The fact is that whether or not we take others into consideration when we >decide to go off in search of adventure, almost invariably they will be >involved when the crap hits the fan. > >The now lowly appreciated and often bad mouthed ELT at one time represented >a break through in safety technology. It most certainly has saved many lives >of both the survivors and those called upon to be their rescuers. > >I am inclined therefore to say that the answer to the opening question is; >Whether we think about it or not the purpose of emergency locators no matter >what type, are intended for the benefit of all the parties potentially >involved, not just for our individual selves. > >Whether buying a maximum affordable minimum requirement unit or spending for >the best technology doodad available, I hope the above considerations help >soften the blow when the time comes to offer up the cash. > >I to hope that the prices for the "approved 406" go down as production ramps >up. >I also look forward to the day that the electronics for this gets so small >that it might become an integral part of every cell and satellite phone for >example. > >Great flights and greased landings > >Jim in Kelowna > > > > ________________________________ Message 14 ____________________________________ Time: 10:18:14 AM PST US From: "Dan Checkoway" Subject: Re: AeroElectric-List: Keep warm circuit for Landing/Taxi lights --> AeroElectric-List message posted by: "Dan Checkoway" > Quick question about Halogens: How well do they survive in a wig-wag setup? is the constant on and off a problem for these bulbs? I have dual 100W halogens in my RV-7, and I leave the wig-wag on all the time -- cheap insurance in the see-and-be-seen dept. Pretty much constantly wig-wagging for 280 hours. The bulbs are still going, no failure yet. Even so, they're only 5 bucks to replace if and when one decides to go. )_( Dan RV-7 N714D http://www.rvproject.com ________________________________ Message 15 ____________________________________ Time: 10:34:03 AM PST US From: "Gilles Thesee" Subject: Re: AeroElectric-List: LVWM questions --> AeroElectric-List message posted by: "Gilles Thesee" REALLY preoccupied right now. Had to put my dad > in the hospital last Wednesday and given that I'm executor of his > estate and power of attorney on his business activities, it's pretty > busy. I'll see if I can get to them this evening. > > Bob . . . Bob, Thank you for your message. Please don't feel in a hurry. I won't go to the airfield before one week or two. Thanks a lot for your help, Best regards, Gilles ________________________________ Message 16 ____________________________________ Time: 10:51:21 AM PST US From: Brian Lloyd Subject: Re: AeroElectric-List:AOA was Stall Horn --> AeroElectric-List message posted by: Brian Lloyd On Nov 13, 2004, at 2:16 PM, Paul Messinger wrote: > First, what is needed is an indication is the amount of lift > remaining, not > a really precision Angle of Attack (AOA). Why do you say that? What I want from an AoA indicator is several points: 1. stall 2. approach 3. best L/D 4. zero lift/zero-AoA (not the same over the wing due to washout) A properly-calibrated AoA indicator gives me these things. I know of no other instrument that does. > There are many ways to sense the > relative AOA in a manner that provides the pilot info on how close the > aircraft is to a stall but also above stall in some "linear" indicator > so > regardless of the aircraft load (pilot and low fuel vs. many > passengers and > fuel) the pilot can determine the correct approach speed for the > aircraft > weight. While the AOA associated with stalling is constant, the speed > that > the stall occurs goes up with wing loading. The classical stall > warning horn > is not suitable for approach speed control as its "all or nothing" and > generally set too close to the real stall to be useful. Are you sure about that? The stall warning vanes with which I am familiar measure the airflow angle of incidence, i.e. AoA. When the AoA passes a critical point the vane moves and you get a stall warning. It should work properly regardless of load on the airframe. At least it seems to when doing accelerated stalls. > Without a good AOA > indicator the pilot must guess how much faster the approach speed must > be > under full load vs. near empty. This also works well in determining > just > when to pull back (rotate) on Take off :-) I agree. AoA is far more important than airspeed. The only time airspeed is important is when you are loading up the airframe. You want stall to occur before the wing can generate more lift than that for which the airframe is stressed. This means you still need to know Va for your aircraft and not exceed it when maneuvering hard unless you are watching the 'G' meter. BTW, I regularly would fly my CJ6A from -2G to +5G. I found the AoA to be far, far more useful than the ASI except in determining the kinetic energy needed for some maneuver. You need airspeed for that. OTOH, when learning new maneuvers and you botch it, it is good to know where zero AoA is so you can keep the airplane from stalling as you fall through and wait for enough airspeed to allow maneuvering flight again. Oh, and the AoA Pro from Proprietary Software does not sense negative AoA, an annoying deficiency. > It's also important to note that there are hundreds of different wing > airfoils and the stalling AOA of each case can and does vary some what > and, > over a large range in some used airfoils. Thus there is not one size > fits > all "AOA" and each aircraft needs to be individually calibrated Not to > suggest that once a RV6 is calibrated that all RV6 aircraft can use > the same > cals. However what worked on a Cessna will not necessarily work for a > RV > etc. Having installed and lived with the AoA Pro from Proprietary Software, I can attest that it works as specified. It properly indicates stall at aircraft loadings from +1G to +5G. It is calibrated for the aircraft. It needs four data points: zero lift (0G ballistic flight), flaps up steady-state stall, flaps up zero lift (0G ballistic flight), flaps down steady-state stall, flaps down Once those points are entered, everything else falls into place. I was amazed at how well it worked. > Now to some basics. > > You have the complex system of pressure difference and computer > equations to > a really fine job but its "in my opinion" a great overkill for many. To > state, as the following post states, this is the only one that works > (not at > all true); there are other systems that also work quite well. The > classical > vane below the wing (Right Angle) and the fixed probe (Lift Reserve), > as > well as the third port on the Dynon Pitot head for example. Well, we had this argument on the RV-list many years ago. The Lift Reserve Indicator does not indicate AoA. AoA is a component but at high loadings it will tell you have lots of reserve lift when that just isn't so. But when flying near 1G, it works just fine. Since I like to yank-n-bank it does not suit my needs. As a purist I find their claim that it is an AoA indicator annoying. Vane type AoA indicators can be made to work just fine. I liked the simplicity of using the airfoil as the probe in the AoA Pro from Proprietary Software. I just needed to do a calibration flight and all was good. > Pitot heads work well in cruise flight but have increasing airspeed > errors > as the real AOA of the head mounted on the wing increases into the > stalling > angle. This error is significant at 10 degrees in many heads and with > the > stalling AOA usually above that, the pitot error is large as the stall > AOA > is reached. This error is used by Dynon to determine the approach to > stall > indication (with a third sensor port). My point is that your statement > that > the airflow is nearly parallel to the wing as its gets very close is > correct > but 6" or more away from the wing the airflow is not parallel and can > be and > is used to determine relative AOA which is reliable info for the > intended > purpose of determining the relative AOA for best safe approach speed. Agreed. There is some change in flow direction and you can calibrate for that to determine AoA. > The C150/172 has a very large airspeed error at the stall (using the > conventional pitot head). The Piper probe set 4" below the middle of > the > wing is much more accurate but not zero error. > > So the moving vane positioned at least 6" below the wing can and does > provide a real means of sensing the needed AOA (Further away is > better). The > Lift reserve system uses a fixed probe with two pressure ports set at > different angles and these probes are also around 6" below the wing.The > Dynon probe is similar to the lift reserve as it has a third pressure > port > set on a face below the normal pitot probe. The difference being that the Dynon uses a third port to sense differential pressure across the probe as well as correcting for static pressure. This means it can know the AoA. The LRI does not correct for static pressure. > All three of the above systems provide cockpit info on the amount of > lift > available and thus the ability to adjust the approach speed (for > example) to > match the aircraft gross weight with the same margin of airspeed. Are you sure? I know that there is an approach AoA. It is independent of loading. I just nail that AoA and I am at the correct approach speed regardless of loading. I suspect that the PS system, Dynon, and Right Angle systems will give proper results under all conditions. I am not convinced that the LRI will do the same. > All are > far simpler that your system and lower cost and do work well. All also > have > something sticking out of the wing which your system does not. To some > that > is a very desirable feature but the end result in info provided to the > pilot > is essentially the same. Potentially your system is more accurate but > as the > simple systems are typically more accurate than the average pilots > ability > to control aircraft attitude, the need for more precision is moot. ANY > system is so much better than none, I suggest the proper sales pitch > is that > everyone needs an AOA system and ours is the best but any is far > better than > none! I agree, modulo the LRI. > I have personally flight tested the moving vane setup on several > different > aircraft and found it to work well and perform as intended. I have a > friend > with a Lift Reserve system on his Bonanza and is very pleased with it > and as > he is a retired airline pilot he knows the value of a AOA system. > Either > system permits safer flight. In a one-G environment, yes. > These systems are not a glorified airspeed (as you suggest) I believe that the LRI is. That is where this whole discussion started about 6 years ago. The LRI was touted as an AoA indicator which it is not. That was the primary competition for the PS AoA Pro. > as they sense > and display the real stalling speed margin as it varies with load. > Depending > on the effectiveness of the flaps there needs to be a flap position > feedback > to the system as the flaps may produce significant changes in the lift > coeficant of the wing. ALL systems are the same in this respect. > However the > pilot can simply fly a slightly different place on the display and > accomplish the result. Not ideal but far better than not having an AOA. The PS AoA has a switch to detect flap position and is calibrated separately for flaps-up and flaps-down flight. It works well. > I > found that even the very effective flaps on the Cessnas could be > compensated > with flying one bar different on the AOA indicator vs flap position > compensation (Nice feature but not a requirement!). > > If you fly an aircraft where the gross weight varies over a small > range like > a single place aircraft there is little need for a AOA system. However > as > the weight range increases to perhaps as much as the empty weight of > the > aircraft then its really helpful and many of us feel it is an essential > device. Or if you fly the aircraft in loaded flight a lot. Remember an aerobatic aircraft is flying over a 600% load range normally. The ASI just isn't much help then. > I reply to your post only because you have made false/misleading > statements > about the competition that need a response. There are lower cost > systems > that do work. ALL systems including yours have advantages and > disadvantages. > Cost, retrofitability, type of aircraft, etc. all are considerations > and one > system does not fit all. Paul, go look at the LRI. It really isn't an AoA instrument. That is where this whole thing started. > > Having an AOA systerm on ALL general aviation aircraft could be a great > safety addition. I agree with this 100% Brian Lloyd 6501 Red Hook Plaza brianl@lloyd.com Suite 201 +1.340.998.9447 St. Thomas, VI 00802 There is a time to laud one's country and a time to protest. A good citizen is prepared to do either as the need arises. ________________________________ Message 17 ____________________________________ Time: 11:26:46 AM PST US From: "Olivier Le Carbonnier" Subject: RE: AeroElectric-List: AOA --> AeroElectric-List message posted by: "Olivier Le Carbonnier" i got (this aafternoon !) my AOA from Van's Aircraft. Olivier LC France ICQ#: 82067330 sanglier@laposte.net http://sangliervolant.chez.tiscali.fr Van's RV-8 n81939 wings -----Message d'origine----- De : owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com]De la part de bakerocb@cox.net Envoy : dimanche 14 novembre 2004 20:52 : aeroelectric-list@matronics.com Objet : AeroElectric-List: AOA --> AeroElectric-List message posted by: From: "Olivier Le Carbonnier" Subject: RE: AeroElectric-List: Stall Horn << ....skip....The difference is that our AOA works....skip....>> 11/14/2004 Hello Olivier, Would you please identify which AOA is *ours* and where to get some information on it? Thanks, OC ________________________________ Message 18 ____________________________________ Time: 12:00:34 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: ELT Access --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 04:02 PM 11/11/2004 -0500, you wrote: >--> AeroElectric-List message posted by: > >AeroElectric-List message previously posted by: "Robert L. Nuckolls, III" nuckolls@cox.net> > ><<....skip....If you have a list of RTCA documents you'd like to see, >post it and I'll see if I can put my hands on them. Bob>> > >11/11/2004 >Hello Bob Nuckolls, Thanks for the offer -- that was the object of my >original request. I am led to believe that the ELT access requirement >would be found in DO-182, DO-183, or DO-204. Thanks for your help. >OC I just found out that the documents you want are not available for downloading (which means they're generally free to members). I would have to order paper copies at the member prices which I can do for you if you wish. We might have them in a library somewhere on the square-mile. I'll see if I can find them. Bob . . . ________________________________ Message 19 ____________________________________ Time: 01:31:40 PM PST US From: "Robert L. Nuckolls, III" Subject: AeroElectric-List: Battery ground? --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" >Bob Hi, > >Can I run my #2 Battery Ground wire separately to the 0-320 motor as >opposed to connecting the Battery ground lead directly to the B & C Single >point ground brass bolt and Ground Strap. > >I have an RV-8 and, the #2 Battery Wire will not reach the B & C single >point ground strip easily. Therefore I've run the ground strap and #2 >Batter Ground wire separately to the same connection point on the motor. I'm concerned that you have #2 battery jumpers. These tend to be pretty stiff and increase risk of battery post breakage due to vibration. I'd like to see you make new jumpers from #4AWG welding cable and while you're at it, make the battery(-) cable long enough to reach the firewall ground stud. Welding cable is easy to get, really inexpensive and nice to work with! I recommend #4 battery jumpers irrespective of the size of fat wires for the rest of the system. The smaller, softer jumpers are much more user and battery friendly. Bob . . . ----------------------------------------- ( Experience and common sense cannot be ) ( replaced with policy and procedures. ) ( R. L. Nuckolls III ) ----------------------------------------- ________________________________ Message 20 ____________________________________ Time: 01:40:37 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Shunt with essential bus --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 08:51 AM 11/15/2004 -0800, you wrote: >--> AeroElectric-List message posted by: "Mitch Faatz" > > > No, that would run starter current through the shunt. All of the > > Z-figures suggest wiring ammeters as alternator loadmeters. Shunts > > in the b-lead of the alternator. ... > >Ah HA! That snapped something in my brain! I was looking at the ammeter as >a general "battery load" meter instead of alternator load meter. So if the >battery/alt switch is turned off and essential bus alternate feedpath is >turned on: no feed to the alternator, ammeter will be zero but who cares >because you're going to land and fix the problem. Better yet, you will have accomplished a load analysis on your e-bus configuration -AND- you will have tracked battery condition by EITHER periodic capacity testing OR periodic replacement of an inexpensive battery. A reasonable >I wanted to use the ammeter as a "system load" meter so even if I was >running essential bus only, I could still see the total load on the system >and verify I'm running a reduce load on the battery. The alternator loadmeter will do that for you . . . if it's a digital device and 0.1A resolution, you can measure the load of any accessory by simply turning it on and off in cruising flight and observe the CHANGE in alternator load. Better yet, do a load analysis of all electro-whizzies in your airplane and KNOW how much each device needs. It may be that you don't NEED any ammeters in the airplane. As I've written before, voltmeters and ammeters do not help you fly the airplane and they are very poor harbingers of bad news . . . they're quiet, small and tend to tell you the same thing 99.9% of every time you look at them. Active notification of low voltage combined with a well considered e-bus and battery of known condition is your 99.9% assurance of comfortable continued flight to airport of intended destination. Once you're on the ground, the multi-meter in your toolbox will probably be more helpful for finding the problem than will any device mounted on your panel. Bob . . . ________________________________ Message 21 ____________________________________ Time: 01:42:25 PM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: List Fund Raiser - New Gift Addition! --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 10:45 AM 11/15/2004 -0700, you wrote: >--> AeroElectric-List message posted by: "William J. Applegate" > > >Hi Matt, > >I kinda feel shortchanged. I donated more than $50 dollars last week >and placed my donation just a few days before this offer started. Any >chance I can get the free download? Thanks............Bill >Applegate.....520-296-1502. > >Matt Dralle wrote: > > >--> AeroElectric-List message posted by: Matt Dralle > > Bill, you need to send this query directly to Matt at his email shown above. A reply to the list-server will probably not be noticed. I'm sure he doesn't monitor ALL of the lists on his system. Bob . . . ________________________________ Message 22 ____________________________________ Time: 02:36:36 PM PST US From: Mickey Coggins Subject: Re: AeroElectric-List: Battery ground? --> AeroElectric-List message posted by: Mickey Coggins Hi, For those of you like me without a welding supply store around the corner, I've ordered some welding cable from McMaster-Carr: http://www.mcmaster.com/nav/enter.asp?partnum=7818A18&pagenum=3142 I don't have it yet, so I can't give much feedback, but it's there. Only costs about 0.72 USD per foot. Mickey At 22:51 15-11-04, Robert L. Nuckolls, III wrote: -----Start of Original Message----- >--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" > > >>Bob Hi, >> >>Can I run my #2 Battery Ground wire separately to the 0-320 motor as >>opposed to connecting the Battery ground lead directly to the B & C Single >>point ground brass bolt and Ground Strap. >> >>I have an RV-8 and, the #2 Battery Wire will not reach the B & C single >>point ground strip easily. Therefore I've run the ground strap and #2 >>Batter Ground wire separately to the same connection point on the motor. > > I'm concerned that you have #2 battery jumpers. These tend to be pretty > stiff and increase risk of battery post breakage due to vibration. > I'd like to see you make new jumpers from #4AWG welding cable and while > you're at it, make the battery(-) cable long enough to reach the > firewall ground stud. > > Welding cable is easy to get, really inexpensive and nice to work > with! I recommend #4 battery jumpers irrespective of the size > of fat wires for the rest of the system. The smaller, softer jumpers > are much more user and battery friendly. > > Bob . . . -- Mickey Coggins http://www.rv8.ch/ #82007 QB Wings/Fuselage ________________________________ Message 23 ____________________________________ Time: 03:26:18 PM PST US From: "Eric M. Jones" Subject: AeroElectric-List: Re: Keep warm circuit for Landing/Taxi lights --> AeroElectric-List message posted by: "Eric M. Jones" I think the use of thermistors for limiting the current surge to filament lamps can be easily improved upon. I looked for a simple solution to this problem and would like to suggest using LM395T Ultra-Reliable Power Transistors. They are $3.38 each or so from Digikey but provide the advantage that they do not get as hot as the thermistors and thus can be put virtually anywhere. The device is operated by tying the Collector and Base together (In) and using the Tab-emitter as output. Thus you wind up with a two-terminal device with a current limit of 2A. For more current you parallel more LM395T's at 2A per step. The voltage drop is about 2 Volts. Thus for a 35W lamp you would need only a pair of these. This would be my choice. Regards, Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge MA 01550-2705 Phone (508) 764-2072 Email: emjones@charter.net "telegraph is a kind of a very, very long cat. You pull his tail in New York and his head meows in Los Angeles. And radio operates exactly the same way-- you send signals here, they receive them there. The only difference is that there is no cat." --Albert Einstein ________________________________ Message 24 ____________________________________ Time: 04:39:34 PM PST US From: "Paul Messinger" Subject: Re: AeroElectric-List:AOA was Stall Horn --> AeroElectric-List message posted by: "Paul Messinger" Extensive comments Thanks. ----- Original Message ----- From: "Brian Lloyd" Subject: Re: AeroElectric-List:AOA was Stall Horn > --> AeroElectric-List message posted by: Brian Lloyd > > > Are you sure about that? The stall warning vanes with which I am > familiar measure the airflow angle of incidence, i.e. AoA. When the > AoA passes a critical point the vane moves and you get a stall warning. > It should work properly regardless of load on the airframe. At least > it seems to when doing accelerated stalls. My point is it is set to sound off at one specific condition. An AOA is an indicator over a range of conditions I think we agree n\just read my comments differently :-) > > > Without a good AOA > > indicator the pilot must guess how much faster the approach speed must > > be > > under full load vs. near empty. This also works well in determining > > just > > when to pull back (rotate) on Take off :-) > > I agree. AoA is far more important than airspeed. The only time > airspeed is important is when you are loading up the airframe. You > want stall to occur before the wing can generate more lift than that > for which the airframe is stressed. This means you still need to know > Va for your aircraft and not exceed it when maneuvering hard unless you > are watching the 'G' meter. True but I have assummed that the AOA is most usefull for normal not aerobats :-) The harder you work the aircraft the wider range the info you need is. > > Having installed and lived with the AoA Pro from Proprietary Software, > I can attest that it works as specified. It properly indicates stall > at aircraft loadings from +1G to +5G. It is calibrated for the > aircraft. It needs four data points: > > zero lift (0G ballistic flight), flaps up > steady-state stall, flaps up > zero lift (0G ballistic flight), flaps down > steady-state stall, flaps down > > Once those points are entered, everything else falls into place. I was > amazed at how well it worked. Not a disagreement but for the 99% of pilots that is much more than needed. > Well, we had this argument on the RV-list many years ago. The Lift > Reserve Indicator does not indicate AoA. AoA is a component but at > high loadings it will tell you have lots of reserve lift when that just > isn't so. But when flying near 1G, it works just fine. Since I like > to yank-n-bank it does not suit my needs. As a purist I find their > claim that it is an AoA indicator annoying. I was at OSH this year and had a long discussion and there was never a claim that it was a true AOA. Its fine for approach and departure to show margins under the full range of acft weights. That it works as well as it does is the result of lots of technical studies when it was first introduced. I have the report packed away from my work on AOA 5 +years ago. > > Vane type AoA indicators can be made to work just fine. I liked the > simplicity of using the airfoil as the probe in the AoA Pro from > Proprietary Software. I just needed to do a calibration flight and all > was good. No question they have the best available but its complex etc and expensive. I just feel its an overkill for most pilots. > > > The C150/172 has a very large airspeed error at the stall (using the > > conventional pitot head). The Piper probe set 4" below the middle of > > the > > wing is much more accurate but not zero error. > > > > So the moving vane positioned at least 6" below the wing can and does > > provide a real means of sensing the needed AOA (Further away is > > better). The > > Lift reserve system uses a fixed probe with two pressure ports set at > > different angles and these probes are also around 6" below the wing.The > > Dynon probe is similar to the lift reserve as it has a third pressure > > port > > set on a face below the normal pitot probe. > > The difference being that the Dynon uses a third port to sense > differential pressure across the probe as well as correcting for static > pressure. This means it can know the AoA. The LRI does not correct > for static pressure. In its intended use it does not need correction. > > > All three of the above systems provide cockpit info on the amount of > > lift > > available and thus the ability to adjust the approach speed (for > > example) to > > match the aircraft gross weight with the same margin of airspeed. > > Are you sure? I know that there is an approach AoA. It is independent > of loading. I just nail that AoA and I am at the correct approach > speed regardless of loading. I suspect that the PS system, Dynon, and > Right Angle systems will give proper results under all conditions. I > am not convinced that the LRI will do the same. In the approach mode as you describe the LRI does work as advertised as documentated in the original independent studies. > > > All are > > far simpler that your system and lower cost and do work well. All also > > have > > something sticking out of the wing which your system does not. To some > > that > > is a very desirable feature but the end result in info provided to the > > pilot > > is essentially the same. Potentially your system is more accurate but > > as the > > simple systems are typically more accurate than the average pilots > > ability > > to control aircraft attitude, the need for more precision is moot. ANY > > system is so much better than none, I suggest the proper sales pitch > > is that > > everyone needs an AOA system and ours is the best but any is far > > better than > > none! > > I agree, modulo the LRI. > > > I have personally flight tested the moving vane setup on several > > different > > aircraft and found it to work well and perform as intended. I have a > > friend > > with a Lift Reserve system on his Bonanza and is very pleased with it > > and as > > he is a retired airline pilot he knows the value of a AOA system. > > Either > > system permits safer flight. > > In a one-G environment, yes. > > > These systems are not a glorified airspeed (as you suggest) > > I believe that the LRI is. That is where this whole discussion started > about 6 years ago. The LRI was touted as an AoA indicator which it is > not. That was the primary competition for the PS AoA Pro. Its not me that suggests that the LRI works, go get the original reports and read them. I suspect that the LRI dealers (two at present) would be able to provide a source for them. This is an old argument that was independently verified. If you accept that the Dynon probe works the LRI is essentially the same as far as both use the differential pressure across the ports to measure effective AOA. > The PS AoA has a switch to detect flap position and is calibrated > separately for flaps-up and flaps-down flight. It works well. My point is many acft have little AOA change with flaps. The Right Angle has provisions for flaps if you need them. My flight tests indicated that other than full flaps on the C150/172 made little difference in the real or indicated lift margin (AOA) in effect. > > Paul, go look at the LRI. It really isn't an AoA instrument. That is > where this whole thing started. Have done that years ago and found that it was a useful device. Reservations removed after flying with one and reading the independent report. As I have said OSH 2004 discussions made no mention of its being more than what the name implied and its use more or less limited to landing and Takeoff under max performance conditions. Adding a pressure transducer and display to the Dynon probe is one way to get Airspeed and AOA from one fixed probe. I would get my copy (of the LRI design) out if I had any idea where its stored in the hundreds of boxes around here. Lots have happened in the past 5 years. I am not promoting any single device. All add safety to flight all have benefits and limitations. My point is there are more than one out there that provides increased safety. Paul 01 Red Hook Plaza > brianl@lloyd.com Suite 201 > +1.340.998.9447 St. Thomas, VI 00802 > > There is a time to laud one's country and a time to protest. A good > citizen is prepared to do either as the need arises. > > ________________________________ Message 25 ____________________________________ Time: 05:58:19 PM PST US From: EMAproducts@aol.com Subject: AeroElectric-List: AOA Comments --> AeroElectric-List message posted by: EMAproducts@aol.com Fellow builders & homebuilt pilots: This is not meant to flame, for any AOA is much better than none! Safety is what is important! However, as a manufacturer of the RiteAngle IIIb AOA system I find it very distressing that someone makes the following claims without evidently knowing all the facts. I have no idea who sent this message as one of my customers in Europe forwarded me the adverse posting by cut and paste. I felt it necessary to comment. I'm proud of our reputation and will back up our products 100% ~ They all work ~ and are reliable and cost effective. Elbie Mendenhall, EMA Products, LLC RiteAngle IIIb, The "Stand Alone AOA System", For your safety my comments are after the >>>> ------------------------------ The difference is that our AOA works. >>>> So does ours, otherwise why would It be installed on the huge variety of aircraft? The production Fire Boss Borate Bombers ~~ Other systems were evaluated, they selected ours. **** If you think about it, the advantage of the under wing pitot tube is that the airflow is always flowing about parallel to the under side of the wing. Because of this the airspeed indication (IAS) is accurate no matter what the angle of attack (AOA). >>>>Basically true, regardless of this fact many production planes still insist in putting the Pitot out in front of the wing (less likely to get people damage I guess **** Conversely, the under wing is a lousy place for an AOA sensor. >>>>How much research have you done in this area? The aerodynamicist that is our consultant had over 30 years with Douglas Aircraft, one of their primary engineers in fighter aircraft design, worked extensively with AOA, other projects were most of the aerodynamic modifications to the Reno Air Race winner Dreadnought, D-558, A-26, A-4, F4D upward to retirement in the 70's. Hundreds of happy customers are the answer. **** This is because the air changes direction way before it reaches the wing and when it reaches the wing the airflow is about parallel to the wing surface no matter what the AOA. Now, if you try to fix this by moving the pitot tube further from the wing to get into undisturbed air, you may improve the AOA sensing ability somewhat but the IAS now has errors with changes in AOA. >>>>We have a totally stand alone system, it does not depend on pitot, static sources or computer programs. It uses the vane aligning itself with the airflow, a natural aerodynamic reaction. Repeatability, accuracy and reliability are the most important things in a safety system. The distance of 13% is also based on getting far enough from the airfoil to get a good reliable, repeatable change in airflow with AOA changes. This has worked on all aircraft if located where instructions suggest. It is not critical like the holes in wing or angle of the mast on other systems where different airfoils take a different location or angle. **** Did you ever wonder why the AOA probes on Airbus airliners are way ahead of the wing on the nose of the fuselage? They actually have to be one and one half chord ahead of the wing to get into undisturbed air. >>>> With no propwash, it is an easy location and close to the electrical bay. Fuel trucks, baggage carts, etc., are always going around and under wings, anything hanging down will get hit. Even the fuselage probes are occasionally hit by the jetbridge. It has errors which are computer corrected, at high AOA the airflow comes at the vane, not from straight ahead, but from around the nose. Hence all indications are relative AOA, not true AOA, a term I believe is correct for all systems unless the system is installed exactly like a test sample in the wind tunnel etc. **** The beauty of our system is that it senses pressures on the top and bottom of the wing (aerodynamic sensing) and divides that differential pressure by the dynamic pressure producing a Cl (coefficient of lift). Those familiar in the art know that coefficient of lift and AOA vary uniquely with each other. We avoid the pit falls of both pressure on probe sensing systems and vane systems. Also you have some redundancy. >>>>What is the redundancy? We considered a system similar to this in the early 90's but were advised variances in each airfoil made it critical for location. We elected to stay away from this complex type of system. Our system has operated over 50 hours on 8 AAA batteries when testing the automatic switch over feature should you lose aircraft electrical power. It will operate if no pitot, no static, no lights etc. on its back up 8 AAA battery pack should you decide to install it **** If you want an AOA that works, let us know. >>>>I take great displeasure at this comment! I have hundreds of satisfied customers in 13 countries around the world flying our systems on aircraft as varied as single seat ultralights, BD-5's, KitFox, RV's, Europa's, Lancair 320 to JetProp, Zenith, Thorps, TL Sting & Sport to the Certified 16,000# Wipaire Fire Boss forest fire fighting aircraft which are operating in US, Canada, & Spain that I know of. Fabric, Metal, composite our system does not care. Currently being STC'd on a Cessna 421 and other aircraft. All the same system, no special locations for holes in wing just a vane flying in the airflow, measuring the AOA, what keeps you in the air. **** Our AOA is based on sound aerodynamic principle . Any other would only be a glorified IAS indicator. >>>>It is evident that someone hasn't done their homework, We have nothing to do with airspeed or computer values based on aerodynamic principle~ ~Our system takes a vane position and flap position and memorizes where you want the LED's to come on. We have up to 6 flap positions the system memorizes so you will be very close to the correct AOA indication regardless of flap position. Some systems have no flap correction, others have up and down only, do you always use none or full flap {Europa monogear excluded :-) } This is for safety. You have to do any maneuver you weren't accomplished at prior to solo to set up our system. Actual vane & flap (if appropriate) positions used, not computed values. Any comments please send to me off list at emaproducts@aol.com I am in middle of a new project (non AOA) and do not monitor this list. Fly Safe, Remember any AOA is much better than none! Naturally I believe ours is best:-) We all have our preferences, you spend your $$ and make your choices, but be correctly informed and investigate before laying out the cold cash. Sincerely, Elbie http://www.riteangle.com/ ________________________________ Message 26 ____________________________________ Time: 06:44:31 PM PST US From: "glaesers" Subject: AeroElectric-List: Re: Keep warm circuit for Landing/Taxi lights clamav-milter version 0.80j on pop-7.dnv.wideopenwest.com --> AeroElectric-List message posted by: "glaesers" I'm afraid I don't get how these work yet. How does the current change with time? Two concerns: 1) 2 Volts is quite a drop, compared to a third of a volt for the thermistor. 2) If it takes 3 of these (6A) to protect a 75W bulb, the protection now costs the same as the bulb and the switch. Can you explain further? Thanks, Dennis Glaeser --> AeroElectric-List message posted by: "Eric M. Jones" I think the use of thermistors for limiting the current surge to filament lamps can be easily improved upon. I looked for a simple solution to this problem and would like to suggest using LM395T Ultra-Reliable Power Transistors. They are $3.38 each or so from Digikey but provide the advantage that they do not get as hot as the thermistors and thus can be put virtually anywhere. The device is operated by tying the Collector and Base together (In) and using the Tab-emitter as output. Thus you wind up with a two-terminal device with a current limit of 2A. For more current you parallel more LM395T's at 2A per step. The voltage drop is about 2 Volts. Thus for a 35W lamp you would need only a pair of these. This would be my choice. Regards, Eric M. Jones www.PerihelionDesign.com ________________________________ Message 27 ____________________________________ Time: 06:58:24 PM PST US From: "Tinne maha" Subject: AeroElectric-List: Two Grounds? --> AeroElectric-List message posted by: "Tinne maha" List, I'm a little confused about grounding. Fig Z-11 shows what I'm interpreting to be both a single point groundAND a connection betweena metal airframe (mine is tubular steel) the negative terminal of the battery. Is the connection to the airframe in addition to the single point groundpreferred over having just a single point ground? (What I'm calling a single point ground is the fat cable running from the ground bus to the battery negative terminal) Thanks, Grant ________________________________ Message 28 ____________________________________ Time: 07:30:18 PM PST US From: "Richard E. Tasker" Subject: Re: AeroElectric-List: Re: Keep warm circuit for Landing/Taxi lights --> AeroElectric-List message posted by: "Richard E. Tasker" I have to agree with Dennis. Most of your devices and ideas (Eric) are great, but I have to question this one. What is the advantage of this arrangement? It does limit the surge current a little more than the thermistor. But once running, the thermistor has this beat hands down! Assuming a 75W light, and using the 8A rated thermistor, the thermistor limits the surge current to about 7A and then warms up to drop about 0.35V. This compared to your results of 6A surge with 2V drop when the lamp stabilizes. So the surge limits are very similar, but the steady state losses for the transistors are almost 6 times the thermistors!. Of course, the lights will last longer with the transistors since they will be running on a reduced voltage (dimmer). What am I missing here??? Dick Tasker glaesers wrote: >--> AeroElectric-List message posted by: "glaesers" > >I'm afraid I don't get how these work yet. How does the current change with >time? > >Two concerns: 1) 2 Volts is quite a drop, compared to a third of a volt for >the thermistor. 2) If it takes 3 of these (6A) to protect a 75W bulb, the >protection now costs the same as the bulb and the switch. > >Can you explain further? > >Thanks, > Dennis Glaeser > >--> AeroElectric-List message posted by: "Eric M. Jones" > > >I think the use of thermistors for limiting the current surge to filament >lamps can be easily improved upon. I looked for a simple solution to this >problem and would like to suggest using LM395T Ultra-Reliable Power >Transistors. They are $3.38 each or so from Digikey but provide the >advantage that they do not get as hot as the thermistors and thus can be put >virtually anywhere. > >The device is operated by tying the Collector and Base together (In) and >using the Tab-emitter as output. Thus you wind up with a two-terminal device >with a current limit of 2A. For more current you parallel more LM395T's at >2A per step. The voltage drop is about 2 Volts. Thus for a 35W lamp you >would need only a pair of these. > >This would be my choice. > >Regards, >Eric M. Jones >www.PerihelionDesign.com > > > > ________________________________ Message 29 ____________________________________ Time: 11:05:20 PM PST US From: "DEAN PSIROPOULOS" Subject: AeroElectric-List: ELTs/SAR --> AeroElectric-List message posted by: "DEAN PSIROPOULOS" >Time: 12:14:01 AM PST US >From: Mickey Coggins >Subject: Re: AeroElectric-List: RE: 406 Mhz GPS ELT >Beyond that, I would carry a handheld Comm unit and a handheld GPS in a small emergency bag that could be easily removed >from the aircraft. And don't forget a cell phone. Seems lately there are news reports of stranded people in really remote areas >able to use a cell phone to call 911. The GPS is key. There was a crash recently in the hills of Oregon where the guys survived >the crash, called 911, and it still took them over 10 hours to be found. One died in the meantime. Good advice Mickey, read on for more reasons why this is so. >The gov't couldn't prove aircraft ELT's save hardly anybody. I searched many years of the NTSB database, and could not find >many cases where an ELT assisted search much at all, much less an actual "save." If the Feds can home in on a low power >pirate radio station in about 15 minutes, it seems like if they wanted to, they should be able to find an ELT that is actually >designed to be found. Not sure why this does not seem to be the case. When I flew search and rescue with the Civil Air Patrol we did alot of training excercises trying to find the infamous 121.5 MHz ELT and became painfully familiar with its limitations (406 MHz ELTs have problems too, just of a different sort). US and Russian satellites (COSPAS SARSAT, check the web and you'll find more info) do an excellent job of picking up the 121.5 ELTs, IF, they've been activated! That's problem number one, sometimes they don't get activated by a crash or the crash forces are in the wrong axis to activate them, that's why the switch on the panel is there on newer airplanes. Problem number two is that they operate on radio frequency and as such must have an antenna AND, the antenna has a certain radiation pattern (see Aeroelectric connection book by Bob Nuckols). That radiation pattern is severly affected by such things as the airplane being upside down or sideways, which can cause strange reflections that make it seem like it is located somewhere else. In Oregon we had large mountains and they can cause really bizarre reflections that make it really hard to home in on an ELT. The wildest goose chase I ever went on was in a training excercise where the IC (incident commander) put the ELT in a metal garbage can that he then tipped on its side. Needless to say, the signal went out sideways and then struck the nearest mountain whereupon it bounced upward, making it seem like the "downed aircraft" was transmitting from the side of that mountain!! We never did find that ELT and the IC was beside himself for several months afterwords. We didn't think it was that funny but nontheless, got lots of flying time in CAP's nice C-182s and learned from the experience. Every state has a CAP squadron and CAP owns 550 aircraft (mostly C-172s/ 182s) that are used for search and rescue (over land, Coast Guard does the overwater stuff and some of the lost mountain hiker stuff). Every CAP aircraft has direction finding equipment used to find 121.5 ELT signals and the folks train very hard to get good at using the stuff (and are very good at it I might add). But there are alot of things working against a successful save. If an ELT goes off it can take a SARSAT a while to fly over and detect it, then there has to be at least two passes of the satellite to determine an approximate (lat/long) position of the hit. By then a couple hours may have gone by. The AFRCC then has to notify the state authorities who then must decide whether or not to call CAP. Then...the CAP IC has to get together an aircrew (pilot, and two observers) and launch. Then..the signal can have the problems I stated above and the aircrew can end up looking for the proverbial wild goose!!! In spite of all this the CAP does a pretty good job of locating downed aircraft, its just that most of the time the occupants have expired. So...that's why you don't see that many "saves" in the NTSB reports. On to 406 MHz ELTs...Unlike 121.5 ELTs which continously send out thier distinctive warbling tone, 406 MHz ELTs send out a signal only periodically. The good thing about this is that that signal contains a burst of data that identifiies the serial number of the ELT. When AFRCC recieves this data block they can (theoretically) look up the owner's name and phone number in thier data base and immediatly call the owner and see if it's a real emergency or just an accidental activation. This is great for false alarms in theory but only if the owner bothers to send in the registration card (doesn' happen alot) or if the ELT hasn't been sold to someone else (also happens, mostly among the boating population that's the lions share of 406 users right now). The other problem has to do with the periodic nature and the short burst of data that 406 ELTs send out. The nature of this transmission makes them much harder to locate precisely by direction finding equipment in the CAP aircraft. Although theoretically the satellite is suppose to be able to locate the 406 ELTs within 2nm of where they are transmitting, once that happens and a DF aircraft is dispatched, it may take the aircrew longer to find the ELT because of the nature of the transmission!!! So...both systems have limitations, we'll see if we get more saves once 406 MHz use becomes widespread. In the meantime, the GPS, cell phone....anything to help locate you faster is a good thing. In waiting for the 406s to come down in price I think I'm just going to buy one of the $200.00 "cheapie" 121.5 ELTs from Vans aircraft. I'd recommend EBAy but these things are finicky enough as it is, I don't want to go buy someone else's unknown quantity. Dean Psiropoulos RV-6A N197DM