---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Sat 11/13/04: 24 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:09 AM - Re: Keep warm circuit for Landing/Taxi (Mickey Coggins) 2. 02:28 AM - Rotax 914, dual alt (manuel bonniot) 3. 04:03 AM - Re: Stall Horn (KITFOXZ@aol.com) 4. 06:34 AM - Re: Re: Keep warm circuit for Landing/Taxi (Robert L. Nuckolls, III) 5. 07:13 AM - Re: 406 Mhz GPS ELT (Eric M. Jones) 6. 08:07 AM - Re: Keep warm circuit for Landing/Taxi lights (glaesers) 7. 08:29 AM - Re: 406 Mhz GPS ELT () 8. 09:48 AM - Re: Antenna Ground Planes on Carbon Fiber (Fred Fillinger) 9. 09:59 AM - Re: Re: Keep warm circuit for Landing/Taxi lights (Richard E. Tasker) 10. 10:16 AM - Re: AOA was Stall Horn (Paul Messinger) 11. 10:24 AM - Re: Re: Keep warm circuit for Landing/Taxi lights (Richard E. Tasker) 12. 11:07 AM - Re: 914 second alternator? (Fred Fillinger) 13. 11:42 AM - Re: 914 second alternator? (Shaun Simpkins) 14. 12:33 PM - Tail Light - Bulb Type? (Jon Finley) 15. 12:51 PM - Re: Re: 406 Mhz GPS ELT (Ernest Christley) 16. 03:00 PM - Re: Keep warm circuit for Landing/Taxi lights (glaesers) 17. 03:05 PM - Re: [Bulk] Re: 406 Mhz GPS ELT (Kevin Horton) 18. 04:09 PM - Re: Re: 406 Mhz GPS ELT (BobsV35B@aol.com) 19. 05:19 PM - Pitot Heat inrush question (glaesers) 20. 05:59 PM - Re: Pitot Heat inrush question (Mike Nellis) 21. 07:48 PM - Re: Pitot Heat inrush question (GMC) 22. 07:55 PM - Re: Re: 406 Mhz GPS ELT (Fred Fillinger) 23. 09:50 PM - Re: Pitot Heat inrush question (Robert L. Nuckolls, III) 24. 09:55 PM - Re: Re: Keep warm circuit for Landing/Taxi (Robert L. Nuckolls, III) ________________________________ Message 1 _____________________________________ Time: 01:09:22 AM PST US From: Mickey Coggins lights Subject: Re: AeroElectric-List: Keep warm circuit for Landing/Taxi lights --> AeroElectric-List message posted by: Mickey Coggins lights Hi Dan, Good find. I think the taxi light, facing aft, would make a great tail light. One on the top of the rudder, and the other on the bottom would rock. Too bad I've already purchased a power sucking A500 for over 150 USD. Mickey >On a related note, has anyone looked at using clear UltraBrite LEDs as recognition lights? Do these do well with a wig-wag setup? This site is marketing a "taxi" light combined with a strobe that may prove interesting in recognition: > >https://ssl.perfora.net/gs-air.com/sess/utn;jsessionid=1541956839198eb/shopdata/index.shopscript > >Dan Fritz -- Mickey Coggins http://www.rv8.ch/ #82007 QB Wings/Fuselage ________________________________ Message 2 _____________________________________ Time: 02:28:45 AM PST US From: "manuel bonniot" Subject: AeroElectric-List: Rotax 914, dual alt --> AeroElectric-List message posted by: "manuel bonniot" Hi Bob and all 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. Well, I studied all your wiring diagrams in appendix Z, and none consider using the rotax alternator, a second alternator running permanently, and 1 battery. I realise the Z-14 is best of the best, but I'd really rather have only 1 battery. The Z-16, with the 2nd alt wired as per Z-13 would fit my needs, but what about the compatibility of both alt running at same time ? Is it possible to keep the OV module on the Rotax alt, and also benefit from the LR3 OV protection ? If an OV occurs, how to know from which regulator it comes ? Finally, what kind of wiring diagram seems to you to be most appropriate to my situation ? Thanks in advance for your help Manuel Bonniot Luxembourg ________________________________ Message 3 _____________________________________ Time: 04:03:54 AM PST US From: KITFOXZ@aol.com Subject: Re: AeroElectric-List: Stall Horn --> AeroElectric-List message posted by: KITFOXZ@aol.com In a message dated 11/8/2004 1:38:54 PM Eastern Standard Time, czechsix@juno.com writes: Guys, Does anyone know of a source for a cheap stall warning horn similar in sound to what's used on spam cans? I made my own spam-style stall vane/tab that I'm putting in the LE of the wing. I bought a piezo alarm from Digikey for something like $1 but it sounds like a fire alarm....it's a bit more shrill and shocking than I want. Aircraft Spruce sells a Safe Flight stall horn with light for $740.00. You read that right...$740! That doesn't include the vane. So anyway, if somebody knows of a non-aircraft source for such a beastie please let me know... Thanks, --Mark Navratil Cedar Rapids, Iowa RV-8A N2D wiring... Mark, take a look at this one: (Radio Shack #273-055) _http://www.radioshack.com/category.asp?catalog%5Fname=CTLG&category%5Fname=CTLG%5F011%5F002%5F003%5F0 00&Page=2_ (http://www.radioshack.com/category.asp?catalog_name=CTLG&category_name=CTLG_011_002_003_000&Page=2) it's not a piezo but, a mechanical buzzer. If mounted in the right place and on the right material, it can make a lot of racket similar to what you are familiar with in a spam can. Question is, will it survive the A/C environment? John P. Marzluf Columbus, Ohio Kitfox Outback (out back in the garage) ________________________________ Message 4 _____________________________________ Time: 06:34:13 AM PST US From: "Robert L. Nuckolls, III" lights Subject: Re: AeroElectric-List: Re: Keep warm circuit for Landing/Taxi lights --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" lights At 11:22 PM 11/12/2004 -0500, you wrote: >--> AeroElectric-List message posted by: "Richard E. Tasker" > > >Actually, if you look at the specific data sheet for these parts: > >Using 75W @ 13V gives us 5.77A - which is close enough to 50% of the 12A >rating. Looking at the data sheet, one finds that the resistance at >this current is 0.06 ohms which gives us a voltage drop of 0.35 V. So, >your 3% calculation is not far off - although I have no idea what you >did to get your numbers. Remember, E=I*R, I=E/R, R=E/I :-) . > >Actually, based on the vendors data sheet, I would probably choose the >next lower size that is rated for 8A max. Using this one, the starting >resistance is 1.3 ohms vs 0.7 ohms for the 12A device. The resistance >at the operating current is essentially the same so the voltage drop >would be the same. Are you interpreting those data values right? These devices have a HIGHER cold resistance than HOT resistance. The I think the numbers you've quoted above are the cold values. This means that when you add 1.3 + wiring + lamp resistance all together, you get about 2 ohms total. Now calculate inrush at about 7A. After the limiter warms up. About two seconds. It's hot resitance should be about 0.1 ohms or less. When the lamp is drawing 5A, then drop across the limiter should be about .5 volts or less. Bo0b . . . ________________________________ Message 5 _____________________________________ Time: 07:13:34 AM PST US From: "Eric M. Jones" Subject: AeroElectric-List: RE: 406 Mhz GPS ELT --> AeroElectric-List message posted by: "Eric M. Jones" Since I was sworn to absolute secrecy on this, I only posted it on my website. But this looks like the ticket. Prices (I hope) soon. http://www.periheliondesign.com/AeroFix%20FCC%20Approved.pdf Regards, Eric M. Jones www.PerihelionDesign.com 113 Brentwood Drive Southbridge MA 01550-2705 Phone (508) 764-2072 Email: emjones@charter.net "Doctors are the same as lawyers; the only difference is that lawyers merely rob you, whereas doctors rob you and kill you too." ~ Anton Chekhov ________________________________ Message 6 _____________________________________ Time: 08:07:52 AM 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" Dick, Thanks for a more complete analysis. I rounded more than you did, so I'm pleased my numbers are as close to yours as they are. I had no clue what to use for a starting resistance for the bulb, so my education is one notch higher. I was also thinking of the next lower size, but wasn't sure about running it closer to it's I-max. Is longevity an issue for things like this that run so hot? For the occasional and relatively short time those lights are on, it's probably a non-issue. Thanks again, Dennis Glaeser ________________________________ Message 7 _____________________________________ Time: 08:29:47 AM PST US From: Subject: AeroElectric-List: RE: 406 Mhz GPS ELT --> AeroElectric-List message posted by: AeroElectric-List message previously posted by: "Eric M. Jones" The reality of the 121.5/243 ELT system is that they will begin to degrade in 2006 (the Russians aren't launching anymore of these satellites). The old system is OFFLINE Feb 2009. Does anyone have a clear description of what is required in OBAM aircraft as far as 406 MHz Emergency Locator Thingies (or whatever)? My guess is not much. There are many more nautical 406 MHz locators. The ACR GlobalFix 406 EPIRB http://store.yahoo.com/landfallnav/globalfix.html can be bought for under $850 in quantity of one. It is possibly to internet together a Buyer's Club to purchase a pallet of these if they are suitable for OBAM aircraft use. Let's see what the price might be and any technical issues before proceeding. Regards, Eric M. Jones 11/13/2004 Hello Eric and Others, There seems to be a great lack of understanding on the subject of ELT's and 406 Mhz ELT's in particular. Let's see if we can create a list of simple factual statements that will reduce the amount of time being spent on conjuring up a 406 Mhz ELT for amateur built experimental aircraft. 1) FAR Sec 1.1 QUOTE: Approved, unless used with reference to another person, means approved by the Administrator. UNQUOTE 2) FAR Sec 91.207 says airplanes must have QUOTE: .....attached to the airplane an approved automatic type emergency locator transmitter that is in operable condition for the following operations.....UNQUOTE. (Some exceptions are permitted.) 3) *automatic type* means activated by a sensing switch upon impact such as in an airplane crash. A manually activated Emergency Position Indicating Radiobeacon (EPIRB) would not be an approved ELT. 4) TSO C126, 406 MHz Emergency Locator Transmitter (ELT), is the normal method the FAA uses to determine that such an ELT is approved. In theory the FAA permits alternate methods of approval, but in the case of a device like a 406 Mhz ELT that interfaces extensively with equipment outside the airplane an alternate approval method would be very expensive and time consuming. Just take a look at TSO C126 and, if you can get them, the referenced RTCA DO documents. 5) The presently available 406 Mhz ELT's are expensive. Aircraft Spruce lists the Artex G406-4 model for $1,456.95. 6) If one desires GPS input to the ELT additional expense and hardware is involved. 7) The GPS input hardware to the Artex 406 Mhz ELT's requires 28 volts. 8) The airworthiness inspector at the initial inspection of an amateur built experimental aircraft would most likely require that an approved ELT be installed. (With a remote control capability from the cockpit, but that is another thread). This *approved* requirement exists because: a) There is no exception for amateur built experimental aircraft from the FAR Sec 91.207 ELT requirement. b) The ELT equipment in the aircraft is expected to operate with external to the aircraft equipment such as the satellites for the SARSAT System without creating any interference to that system or other aircraft.## There does not appear to be a readily available, inexpensive, cookbook approach to putting 406 Mhz ELT's into our amateur built experimental aircraft. I welcome additional useful factual additions to the above list. OC ##PS: I make this point because not every item in the amateur built experimental aircraft fulfilling a FAR requirement for approved equipment must, in fact, be approved. Seat belts and shoulder harnesses are two items in this category. You must have them, but they need not be approved by TSO or otherwise. ________________________________ Message 8 _____________________________________ Time: 09:48:35 AM PST US From: "Fred Fillinger" Subject: Re: AeroElectric-List: Antenna Ground Planes on Carbon Fiber --> AeroElectric-List message posted by: "Fred Fillinger" > AeroElectric-List message posted by: "Giffen A. Marr": > > I am getting ready to install the ground plane for my transponder > antenna mounted on the bottom outside on a Lancair IV-P. > The manual calls for a 12 inch round ground plane installed on > the inside of the aircraft, between the gear legs. A week or so > ago, there was a post that said that the ground plane for the > transponder should be 5.2 inches in diameter. I have two > questions: > Is there anything to be gained by going to a 12 inch ground > plane as opposed to the 5.2 inch diameter specified in the post > and does it make any difference on a carbon fiber aircraft > whether the ground plane is located on the inside or outside of > the skin? > Narco also says, for nonmetal aircraft skin, use a minimum 12" diameter ground plane. I would presume they know what's best to tell transponder installers, and it's probable that once beyond some radius referenced to 1/4 wavelength -- 2.6" with the fudge factor, it doesn't matter much. I'll propose also that affixing it to carbon fiber skin, whether electrically bonded to the actual black stuff or not, makes it further moot. I've fiddled with a crude test setup at VHF frequencies and a monopole antenna, using an antenna analyzer. Yes, there was an effect to adding black cloth larger than the 1/4 wave length ground plane. It appeared similar on either side of the foil ground plane -- simulating it being either inside or outside the A/C -- but nothing to write home about. Reg, Fred F. ________________________________ Message 9 _____________________________________ Time: 09:59:45 AM 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" Uumm, yes... What about my discussion leads you to think that I calculated it incorrectly? When I said that "The resistance at the operating current is essentially the same so the voltage drop would be the same.", I meant the same as the higher rated unit. Sorry if that was unclear. Dick Robert L. Nuckolls, III wrote: >--> AeroElectric-List message posted by: "Robert L. Nuckolls, III" lights > >At 11:22 PM 11/12/2004 -0500, you wrote: > > >>--> AeroElectric-List message posted by: "Richard E. Tasker" >> >> >>Actually, if you look at the specific data sheet for these parts: >> >>Using 75W @ 13V gives us 5.77A - which is close enough to 50% of the 12A >>rating. Looking at the data sheet, one finds that the resistance at >>this current is 0.06 ohms which gives us a voltage drop of 0.35 V. So, >>your 3% calculation is not far off - although I have no idea what you >>did to get your numbers. Remember, E=I*R, I=E/R, R=E/I :-) . >> >>Actually, based on the vendors data sheet, I would probably choose the >>next lower size that is rated for 8A max. Using this one, the starting >>resistance is 1.3 ohms vs 0.7 ohms for the 12A device. The resistance >>at the operating current is essentially the same so the voltage drop >>would be the same. >> >> > > Are you interpreting those data values right? These devices have a HIGHER >cold > resistance than HOT resistance. The I think the numbers you've quoted > above are the cold values. This means that when you add 1.3 + wiring + > lamp resistance all together, you get about 2 ohms total. Now calculate > inrush at about 7A. After the limiter warms up. About two seconds. It's > hot resitance should be about 0.1 ohms or less. When the lamp is drawing > 5A, then drop across the limiter should be about .5 volts or less. > > Bo0b . . . > > > > ________________________________ Message 10 ____________________________________ Time: 10:16:04 AM PST US From: "Paul Messinger" Subject: Re: AeroElectric-List:AOA was Stall Horn --> AeroElectric-List message posted by: "Paul Messinger" Its an interesting statement where facts are taken out of context and a conclusion made that only "mine works". Sadly your conclusion is incorrect. Its one thing to suggest your system is the greatest (OK; its just advertising) but to suggest that the other competing systems do not work is "at best not nice" as its simply incorrect to suggest that. I am a retired Aeronautical engineer (aerodynamics area) and some 5 years ago was interested in developing a "AOA" indicator for my personal aircraft as well as potentially a very low cost system for use in the experimental aircraft market. My comments are intentionally worded to allow non engineers to understand my point and as such, are not always precise engineering. BTW I determined that a minimal featured system could be sold for under $200 (and still can be). First, what is needed is an indication is the amount of lift remaining, not a really precision Angle of Attack (AOA). 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. 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 :-) 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. 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. 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. 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. 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. 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 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. These systems are not a glorified airspeed (as you suggest) 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. 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. 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. Having an AOA systerm on ALL general aviation aircraft could be a great safety addition. Paul ----- Original Message ----- From: "Olivier Le Carbonnier" Subject: RE: AeroElectric-List: Stall Horn > --> AeroElectric-List message posted by: "Olivier Le Carbonnier" > > yes but the answer from man from AngleOffAttack is: > ------------------------------ > The difference is that our AOA works. 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). > Conversely, the under wing is a lousy place for an AOA sensor. 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. 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. > > 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. > > Consequently, we sell more AOAs than all the other AOA folks combined. If > you want an AOA that works, let us know. Our AOA is based on sound > aerodynamic principle . Any other would only be a glorified IAS indicator. > ---------------------------------------------------- > Olivier > > -----Message d'origine----- > De : owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com]De la part de Matt > Prather > Envoy : mercredi 10 novembre 2004 16:33 > : aeroelectric-list@matronics.com > Objet : RE: AeroElectric-List: Stall Horn > > > --> AeroElectric-List message posted by: "Matt Prather" > > > I'll take this opportunity to correct myself a bit.. Aircraft spruce has a > vane style unit for $545 here: > > http://www.aircraftspruce.com/catalog/inpages/aoartangle.php > > It seems they pretty much go up from there. Another option, depending > on how much cool stuff you are going to put in the panel is the Dynon > EFIS. They are having some teething trouble, but I think they'll sort it > out. They offer an AOA pitot probe for $200 (only works with their > EFIS). The total cost would be about $2600 which while a pretty good > value is not cheap. > > http://www.aircraftspruce.com/catalog/avpages/efisd10.php > > Matt- > > > --> AeroElectric-List message posted by: "Olivier Le Carbonnier" > > > > > > where ? > > > > Olivier > > > > -----Message d'origine----- > > De : owner-aeroelectric-list-server@matronics.com > > [mailto:owner-aeroelectric-list-server@matronics.com]De la part de Matt > > Prather > > Envoy : mardi 9 novembre 2004 21:19 > > : aeroelectric-list@matronics.com > > Objet : RE: AeroElectric-List: Stall Horn > > > > > > --> AeroElectric-List message posted by: "Matt Prather" > > > > > > Not cheap... I have seen them start at $600. > > > > MAP > > > >> --> AeroElectric-List message posted by: "Olivier Le Carbonnier" > >> > >> > >> why not a AOA ? > >> > >> 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 > >> czechsix@juno.com > >> Envoy : lundi 8 novembre 2004 19:34 > >> : aeroelectric-list@matronics.com; rv-list@matronics.com > >> Objet : AeroElectric-List: Stall Horn > >> > >> > >> --> AeroElectric-List message posted by: "czechsix@juno.com" > >> > >> > >> > >> Guys, > >> > >> Does anyone know of a source for a cheap stall warning horn similar in > >> sound to what's used on spam cans? I made my own spam-style stall > >> vane/tab that I'm putting in the LE of the wing. I bought a piezo > >> alarm from Digikey for something like $1 but it sounds like a fire > >> alarm....it's a bit more shrill and shocking than I want. Aircraft > >> Spruce sells a Safe Flight stall horn with light for $740.00. You > >> read that right...$740! That doesn't include the vane. So anyway, if > >> somebody knows of a non-aircraft source for such a beastie please let > >> me know... > >> > >> Thanks, > >> > >> --Mark Navratil > >> Cedar Rapids, Iowa > >> RV-8A N2D wiring... > >> > >> Sign up for Juno Today at http://www.juno.com! > >> Look for special offers at Best Buy stores. > >> > >> > > > > > > ________________________________ Message 11 ____________________________________ Time: 10:24:17 AM 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 can't speak from experience (plane is still under construction), but they are designed for this type application and should work fine. Their temperature rating is -50 to 175C. Using their calculations for temperature rise, the 8A rated unit running at 6A would have a temperature rise of 92C. When added to an ambient of 40C (assuming a hot day) gives you 132C - still 43C lower than the maximum allowed temperature. According to their data, the 8A rated unit can handle 6A at temperatures up to 100C before exceeding its design ratings. I believe either would work fine, but your choice. Dick Tasker glaesers wrote: >--> AeroElectric-List message posted by: "glaesers" > >Dick, > >Thanks for a more complete analysis. I rounded more than you did, so I'm >pleased my numbers are as close to yours as they are. I had no clue what to >use for a starting resistance for the bulb, so my education is one notch >higher. > >I was also thinking of the next lower size, but wasn't sure about running it >closer to it's I-max. Is longevity an issue for things like this that run >so hot? For the occasional and relatively short time those lights are on, >it's probably a non-issue. > >Thanks again, > > Dennis Glaeser > > > > ________________________________ Message 12 ____________________________________ Time: 11:07:07 AM PST US From: "Fred Fillinger" Subject: Re: AeroElectric-List: 914 second alternator? --> AeroElectric-List message posted by: "Fred Fillinger" Ronald J. Parigoris wrote: > I was looking through aircraft spruce tonight and saw a 8 amp permanent magnet > alternator. > > Would this work on a vacuum pad on a rotax 914 and put out rated amps? Not enough RPM at cruise, due the gear ratio of the 914 redrive box. I'd figure 5A for planning purposes. Does your 914 have the pump drive kit installed? If not, the drive kit isn't cheap, meaning fair bucks total for just a few extra amps, but I found it easy to install on a new engine. > If I were to run second fuel pump from this and a 2 amp strobe power supply, what sort of > battery would be needed? If you're concerned about the small probability of complete failure of the main electrical system and also the B&C alternator, then you'd want enough reserve capacity to be able to run one fuel pump + maybe engine instrumentation long enough to land someplace fairly soon now. As a practical matter, a 5-7Ah sealed, lead-acid battery is cheap and light, so why fuss over probabilities. > Could you get away with no battery? B&C would have to say if the regulator could be damaged, but still the setup could be noisy enough to cause problems in the avionics. Maybe enough size in an electrolytic capacitor would fix it though. If the idea is also emergency power for one fuel pump and maybe engine instrumentation, upon failure of everything else, at low RPM like on final, the B&C "8 amp" alternator may not enable enough fuel flow. > If not any other ideas? If all you'll run on the B&C setup are the boost/emergency backup pump plus strobes, 2A worth of strobe power doesn't sound like enough light output per FAA rules, meaning for daytime use not worth anything for safety, IMO. So unless you want something for almost-legal and occasional night flight, you could go for day-VFR only. If you want fully redundant power for one pump, it's possible a switchable pack of alkaline D-cells may supply enough (plus the fuel pressure gauge) to be of value. A timed test with the engine not running -- worst case for current draw -- is worth a try. I recall FAA has approved at least one certified plane with such a periodically-replaced alkaline pack to supply IFR backup power to an electric AH gyro, presumably roughly same draw as the 914 fuel pump. Reg, Fred F. ________________________________ Message 13 ____________________________________ Time: 11:42:04 AM PST US From: "Shaun Simpkins" Subject: AeroElectric-List: RE: 914 second alternator? --> AeroElectric-List message posted by: "Shaun Simpkins" Check the Europa-List archives for the April-June 2001 timeframe. I posted several lengthy articles on this. Basically, you can add an SD-8 or SD-20 to the Rotax vacuum pump pad, but because the pump drive spins more slowly than AND2000 standards, you will get much less current. The 914 PTO spins even more slowly, with less output. From my posting of 4/27/01 entitled: "Re: Europa_Mail: Speeding up the Rotax 914 Vacuum Pump PTO" "Note the clear knee in the output curves. The SD-8 and 20 are clearly designed for the Lycoming, and, perhaps conveniently, the 912, but on the 914 the SD-8 is down 40% or so at economy cruise, and down 15% at max RPM. The SD-20 is no better than 50% of rating! Note also that at most cruise power settings the Rotax internal generator is producing full output!" This is why Rotax's recommended additional alternator uses a belt off the prop shaft. One Europa builder went so far as to mount a Honda alternator to the rear shaft bearing of the 914 driven by a flexshaft. To get 10A off the Rotax PTO, you need to use an SD-20, but this is an expensive and heavy "solution" that doesn't fit within the Europa cowling. But then, neither does the belt drive alternator. Shaun ________________________________ Message 14 ____________________________________ Time: 12:33:07 PM PST US From: "Jon Finley" Subject: AeroElectric-List: Tail Light - Bulb Type? --> AeroElectric-List message posted by: "Jon Finley" Hi all, I've got a little project going and I'm not near the airport to check on this myself. I have Whelan position lights. Could someone please tell me whether the tail light is the type of bulb with the two little nubs (that retain the bulb in the socket) the same distance from the 'end' of the bulb or are they off-set (like the multi-filament break light bulbs)?? Thanks so much!! Jon Finley N90MG Q2 - Subaru EJ-22 DD - 465 Hrs. TT Apple Valley, Minnesota http://www.FinleyWeb.net/Q2Subaru ________________________________ Message 15 ____________________________________ Time: 12:51:19 PM PST US From: Ernest Christley Subject: Re: AeroElectric-List: RE: 406 Mhz GPS ELT --> AeroElectric-List message posted by: Ernest Christley bakerocb@cox.net wrote: > 5) The presently available 406 Mhz ELT's are expensive. Aircraft Spruce lists the Artex G406-4 model for $1,456.95. My plan: Buy the cheapest, sorriest excuse for an ELT that I can get off eBay that will pass the inspection right now.** Upgrade to the 406MHz device when the price becomes more reasonable.*** Carry the cheaper handheld devices on any cross country. **Not being found is somewhat less of a worry for me. I live in the heavily populated Eastern US. ***The assumption is that the price will drop, because the price of electronics always drops. But these are TSO'ed aviation devices. With the FAA watching over them, they don't have to follow the laws of economics that everything else does. -- http://www.ernest.isa-geek.org/ "This is by far the hardest lesson about freedom. It goes against instinct, and morality, to just sit back and watch people make mistakes. We want to help them, which means control them and their decisions, but in doing so we actually hurt them (and ourselves)." ________________________________ Message 16 ____________________________________ Time: 03:00:33 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" Whew - they do get hot! And (6A-squared * .06 ohms) means it's putting out 2.16W. I agree that the 8A unit is the way to go. Any recommendations on physical installation? Would it be better to install it near the light, or at the switch end - or does it matter? Dennis Glaeser --> AeroElectric-List message posted by: "Richard E. Tasker" I can't speak from experience (plane is still under construction), but they are designed for this type application and should work fine. Their temperature rating is -50 to 175C. Using their calculations for temperature rise, the 8A rated unit running at 6A would have a temperature rise of 92C. When added to an ambient of 40C (assuming a hot day) gives you 132C - still 43C lower than the maximum allowed temperature. According to their data, the 8A rated unit can handle 6A at temperatures up to 100C before exceeding its design ratings. I believe either would work fine, but your choice. Dick Tasker ------------------------------------------ ________________________________ Message 17 ____________________________________ Time: 03:05:25 PM PST US From: Kevin Horton Subject: Re: [Bulk] AeroElectric-List: RE: 406 Mhz GPS ELT --> AeroElectric-List message posted by: Kevin Horton >--> AeroElectric-List message posted by: "Eric M. Jones" > >Since I was sworn to absolute secrecy on this, I only posted it on my >website. But this looks like the ticket. Prices (I hope) soon. > >http://www.periheliondesign.com/AeroFix%20FCC%20Approved.pdf That is an interesting device, but it doesn't look like it qualifies as an "approved" ELT. It would need to have a means to automatically activate it, and it would need an airframe mounted antenna at the very least. So, it might be a very useful device to have in your pocket, but you would still need to have an approved ELT. Kevin Horton RV-8 (Finishing Kit) Ottawa, Canada http://go.phpwebhosting.com/~khorton/rv8/ ________________________________ Message 18 ____________________________________ Time: 04:09:10 PM PST US From: BobsV35B@aol.com Subject: Re: AeroElectric-List: RE: 406 Mhz GPS ELT --> AeroElectric-List message posted by: BobsV35B@aol.com In a message dated 11/13/2004 2:51:53 PM Central Standard Time, echristley@nc.rr.com writes: My plan: Buy the cheapest, sorriest excuse for an ELT that I can get off eBay that will pass the inspection right now.** Upgrade to the 406MHz device when the price becomes more reasonable.*** Carry the cheaper handheld devices on any cross country. Good Afternoon Ernest, You bring up a very good point. Why should we be forced to carry an ELT at all? Someone earlier said it was forced upon us by a congressman who lost a friend in a survivable accident in Alaska. My recollection is that it was a U. S. Senator from Colorado that shoved it down our throats. I think the name was Dominick or something close to that. I believe his friend died from exposure after a few days when no one was searching for him and I believe the location was here in the lower forty-eight. If not in Colorado, at least, somewhere in the West. Personally, as long as portable radios have been available, I have carried one with me any time that I strayed from heavily traveled byways (like following Highway 66). Anybody but me remember the Baysides? I also carried a high altitude Jeppesen chart that showed what frequencies the air carrier traffic would be using in the area over which I was flying. If I was in good enough shape following the accident to get out the radio, I would have tuned it to the area frequency and waited until I heard somebody give a position report. Believe it or not, we formerly made a lot of such reports. As soon as the report was completed, the plan was to call the aircraft and tell them of my problem. Before 9-11, hardly anybody ever monitored 121.5. You had a much better chance of working a flight that was on center than you did of raising anybody on 121.5. But, I am wandering again. The point I wish to make is that it should be up to us as individuals to make the decision as to how much protection we desire should an unfortunate occurrence befall us. I think my old method was lot better than the ELT solution as it was forced upon us in the early days of such a requirement. I suppose the new 406 with GPS supplementation would be nice to have, but is it really necessary for us to have that much protection from ourselves? I would put in no more than was required to meet the absolute minimum FAA standard. 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. That is what I do now. With a double supply of batteries for the handhelds, I think I am protected as much as I want to be. I don't give a hoot whether the ELT works or not. Happy Skies, Old Bob AKA Bob Siegfried Ancient Aviator Stearman N3977A Brookeridge Airpark LL22 Downers Grove, IL 60516 630 985-8502 ________________________________ Message 19 ____________________________________ Time: 05:19:05 PM PST US From: "glaesers" Subject: AeroElectric-List: Pitot Heat inrush question --> AeroElectric-List message posted by: "glaesers" I was thinking (always a dangerous endeavour)... if it is a good idea to use a thermistor to limit the inrush on a landing/taxi light, what about Pitot Heat? It's also just a big (about 100W I think) resistive load, sort of like a light bulb - just not as bright. Or is it... It just so happens that a heated pitot is the one thing I have! (a used Cessna unit - bought on eBay) My multi-meter says it has 2.2 ohms cold. So at 13V, that means 5.9A of current initially. So apparently it is different than a light bulb which has a much lower resistance when cold. If my 100W assumption is correct, then at 13V the current is 7.69A. So that would indicate not much of an inrush is going on, so no thermistor needed. Does this sound right? Thanks, Dennis Glaeser ________________________________ Message 20 ____________________________________ Time: 05:59:54 PM PST US From: Mike Nellis Subject: Re: AeroElectric-List: Pitot Heat inrush question --> AeroElectric-List message posted by: Mike Nellis I did some bench testing a few years ago with a 5814 heated pitot tube. You can see a graph of the current vs time analysis here http://bmnellis.com/pitotcurrent.htm There is also a link on the page that shows the actual data. Keep in mind this was a bench test so inflight data might be a little different with the air rusing by and cooling things down. http://bmnellis.com/pitotcurrent.htm -- Mike Nellis Austin, TX CMRA #32 Honda RC51 '97 YZF1000 '47 Stinson 108-2; RV6 (Fuselage) http://bmnellis.com glaesers wrote: >--> AeroElectric-List message posted by: "glaesers" > >I was thinking (always a dangerous endeavour)... if it is a good idea to >use a thermistor to limit the inrush on a landing/taxi light, what about >Pitot Heat? It's also just a big (about 100W I think) resistive load, sort >of like a light bulb - just not as bright. > >Or is it... > >It just so happens that a heated pitot is the one thing I have! (a used >Cessna unit - bought on eBay) My multi-meter says it has 2.2 ohms cold. So >at 13V, that means 5.9A of current initially. So apparently it is different >than a light bulb which has a much lower resistance when cold. If my 100W >assumption is correct, then at 13V the current is 7.69A. So that would >indicate not much of an inrush is going on, so no thermistor needed. > >Does this sound right? > >Thanks, > > Dennis Glaeser > > > > ________________________________ Message 21 ____________________________________ Time: 07:48:27 PM PST US From: GMC Subject: RE: AeroElectric-List: Pitot Heat inrush question --> AeroElectric-List message posted by: GMC Hi Dennis I purchased a used AN 5812 Cessna style pitot from a radio shop that is going out of business, they had used the pitot as a loaner. The shop measured and recorded the current inrush at 14.01 volts as 16 amps tapering to 10 amps. Manufacturers paperwork states that this pitot draws 6.4 to 8 amps. George in Langley --> AeroElectric-List message posted by: "glaesers" I was thinking (always a dangerous endeavour)... if it is a good idea to use a thermistor to limit the inrush on a landing/taxi light, what about Pitot Heat? It's also just a big (about 100W I think) resistive load, sort of like a light bulb - just not as bright. Or is it... It just so happens that a heated pitot is the one thing I have! (a used Cessna unit - bought on eBay) My multi-meter says it has 2.2 ohms cold. So at 13V, that means 5.9A of current initially. So apparently it is different than a light bulb which has a much lower resistance when cold. If my 100W assumption is correct, then at 13V the current is 7.69A. So that would indicate not much of an inrush is going on, so no thermistor needed. Does this sound right? Thanks, Dennis Glaeser ________________________________ Message 22 ____________________________________ Time: 07:55:47 PM PST US From: "Fred Fillinger" Subject: Re: AeroElectric-List: RE: 406 Mhz GPS ELT --> AeroElectric-List message posted by: "Fred Fillinger" > --> AeroElectric-List message posted by: BobsV35B@aol.com > > My recollection is that it was a U. S. Senator from Colorado that shoved > it down our throats. I think the name was Dominick... Yup. The below link has history of the ELT, discusses the various TSO's, and the 406mHz issue: http://www.iawg.cap.gov/DSM/beaconstory.htm > 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. > I think my old method was lot better than the ELT solution as it was forced > upon us in the early days of such a requirement. 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." To the contrary, it's common to read about crashes in very remote areas, where NTSB still cites a witness report or someone reporting a probable crash near yonder mountain to police. I tried some CAP web sites; you'd think if their unit ever saved anyone in an airplane, they'd brag about it. No luck. I checked the site of the gov't consortium that oversees all this. They cite one year, 2002, where worldwide, 57 people in aviation incidents were rescued. That's not many at all on this big planet, even if the self-serving statistic has exaggerated what really were saves due to an ELT (they use the weasel word "assisted"), as gov'ts like to do. Reg, Fred F. ________________________________ Message 23 ____________________________________ Time: 09:50:06 PM PST US From: "Robert L. Nuckolls, III" Subject: RE: AeroElectric-List: Pitot Heat inrush question --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 07:47 PM 11/13/2004 -0800, you wrote: >--> AeroElectric-List message posted by: GMC > > >Hi Dennis > >I purchased a used AN 5812 Cessna style pitot from a radio shop that is >going out of business, they had used the pitot as a loaner. The shop >measured and recorded the current inrush at 14.01 volts as 16 amps tapering >to 10 amps. Manufacturers paperwork states that this pitot draws 6.4 to 8 >amps. > >George in Langley > > >--> AeroElectric-List message posted by: "glaesers" > > >I was thinking (always a dangerous endeavour)... if it is a good idea to >use a thermistor to limit the inrush on a landing/taxi light, what about >Pitot Heat? It's also just a big (about 100W I think) resistive load, sort >of like a light bulb - just not as bright. > >Or is it... > >It just so happens that a heated pitot is the one thing I have! (a used >Cessna unit - bought on eBay) My multi-meter says it has 2.2 ohms cold. So >at 13V, that means 5.9A of current initially. So apparently it is different >than a light bulb which has a much lower resistance when cold. If my 100W >assumption is correct, then at 13V the current is 7.69A. So that would >indicate not much of an inrush is going on, so no thermistor needed. > >Does this sound right? Here's some data I took on a bunch of heated tubes off a Beechjet about three years ago. These are 26 volt nominal tubes rated at about 250W while melting ice. http://www.aeroelectric.com/Pictures/Pitot_Heater_R.pdf The curve shows temperature resistance measurement for the tubes in a vacuum. The chart in the upper left corner is current draw while in a crushed ice bath (zero C). Note that while the surface of the tubes were at freezing, the heaters were running about 140 degrees C and had a resistance of about 2.7 ohms. Scaling these down to a 100W tube would increase the operating resistance to about 6.76 ohms for a 26v tube, and 3.88 ohms for a 13v tube. Assuming the same temperature coefficient for the heater material, a 3.38 ohm operating heater setting at 0C waiting to be turned on will have a cold resistance on the order of 2.63 ohms for an inrush at 13 volts of 5A. So what you've measured on the tube you have in hand is consistent with the measurements I've made on other tubes. I had an unmarked 13v tube in my shop a couple years ago that a builder wanted test data on. It's inrush was just over 16A and settled out at 12A in the ice bath for what I would have called a 150 watt tube. 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 24 ____________________________________ Time: 09:55:07 PM PST US From: "Robert L. Nuckolls, III" lights Subject: Re: AeroElectric-List: Re: Keep warm circuit for Landing/Taxi lights --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" lights At 05:52 PM 11/13/2004 -0500, you wrote: >--> AeroElectric-List message posted by: "glaesers" > > >Whew - they do get hot! And (6A-squared * .06 ohms) means it's putting out >2.16W. I agree that the 8A unit is the way to go. Any recommendations on >physical installation? Would it be better to install it near the light, or >at the switch end - or does it matter? > >Dennis Glaeser I used these on the GP-180 in the taxi light fixtures. we made some fiberglas "socks" to slip over the device using wood-burning stove door gasket material you can buy at any fireplace store. A tripple layer of glas kept the clamp that mounted it from soaking off the heat. 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 _-=====================================================================