---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Tue 12/27/11: 24 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 01:41 AM - First Engine Start Problem (Dan Billingsley) 2. 04:11 AM - Re: Relays (Robert L. Nuckolls, III) 3. 04:17 AM - Re: First Engine Start Problem (Robert L. Nuckolls, III) 4. 06:06 AM - Dynon Skyview Airspeed Calibration... () 5. 06:14 AM - Re: First Engine Start Problem (ROGER & JEAN CURTIS) 6. 06:51 AM - Re: First Engine Start Problem (Dan Billingsley) 7. 07:05 AM - Re: Garmin 696 Data Out (Valovich, Paul) 8. 07:14 AM - Re: Dynon Skyview Airspeed Calibration... (racerjerry) 9. 07:19 AM - Re: Dynon Skyview Airspeed Calibration... (paul wilson) 10. 07:19 AM - Re: First Engine Start Problem (Tim Perry) 11. 07:33 AM - Re: Re: Dynon Skyview Airspeed Calibration... (n801bh@netzero.com) 12. 07:38 AM - Re: First Engine Start Problem (zodiac601) 13. 08:34 AM - Re: Dynon Skyview Airspeed Calibration... (The Kuffels) 14. 08:51 AM - Re: Re: Dynon Skyview Airspeed Calibration... (Kevin Horton) 15. 08:59 AM - Re: Relays (bnelson79@charter.net) 16. 09:22 AM - Re: Dynon Skyview Airspeed Calibration... (Gerry van Dyk) 17. 10:26 AM - Re: Re: First Engine Start Problem (Robert L. Nuckolls, III) 18. 10:27 AM - Re: Relays (Robert L. Nuckolls, III) 19. 10:29 AM - Re: First Engine Start Problem (Robert L. Nuckolls, III) 20. 01:39 PM - Re: Re: Dynon Skyview Airspeed Calibration... (Bill Bradburry) 21. 05:44 PM - Re: First Engine Start Problem (Dan Billingsley) 22. 08:58 PM - Re: Relays (Bill Nelson) 23. 09:16 PM - Re: Dynon Skyview Airspeed Calibration... (Matt Dralle) 24. 10:36 PM - Dynon Skyview vs. GRT HX EFIS... (Matt Dralle) ________________________________ Message 1 _____________________________________ Time: 01:41:54 AM PST US From: Dan Billingsley Subject: AeroElectric-List: First Engine Start Problem Bob,=0AI have had the Kitfox wiring completed for about 8 months now and I used the new Z-16 schematic. I have most of my avionics on the E-Bus and th ey have been working well since day one when I first flipped the switch. A week ago the day came to do my first engine start. As it goes with the Rota x 912uls, we purged the oil system then began turning the prop looking for oil pressure. After turning it through several times by hand we decided to then let the starter do the work. The starter turned the engine over well, however, I was dismayed when my whole panel of avionics went dead. I of cou rse quit cranking and began troubleshooting. It didn't take long to find th at the fuseable link off the Batt Contactor (heading to the E-Bus) burned t hrough. I went ahead and bypassed the link with 16 AWG and was able to comp lete a successful first engine start. The guys that were working with me as ked me why that link was there...I did not have a good answer for them. I do have the diode in place, yet I assume a "spike" occurred when I turned the engine over. So...I am now reluctant to put another fuseable link in pl ace but have a concern if there is still a problem that burned my link in t he first place.-=0AI am open to comments and suggestions.-=0AThanks,=0A Dan Billingsley=0AMesa, AZ ________________________________ Message 2 _____________________________________ Time: 04:11:33 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Relays At 10:13 PM 12/25/2011, you wrote: > >What is the difference between a battery relay and a starter relay? >I have a Rans S12S and the circuit diagram for the Rotax 912ULS >engine shows both. But I just got the plane and it only has what I >think is a starter relay with the rotary starter switch and a simple >SPST master switch. Do I need to add the battery relay? Probably not. You've got a day-vfr-fair weather machine with few incentives for adding lots of 'conveniences'. The Piper Tri-Pacer in which I took early flying lessons had a battery switch and a starter push-button. No relays at all. The FUNCTIONALITY for the two devices is very different. The battery switch/contactor is designed to use a minimum of power and is expected to SWITCH rather light loads while being able to CARRY the occasional starter current. The starter contactor needs to SWITCH large inrush loads without welding contacts. Power drain is not an issue because its operating duty cycle is very low . . . seconds per flight cycle. Hence, the starter switch/contactor is designed for the more demanding service as a control device. If what you have has been vetted by folks who have been-there-done-that . . . there's no compelling rationale for changing anything. If they become troublesome, get with us here on the List and we'll help you craft a more robust alternative. Bob . . . ________________________________ Message 3 _____________________________________ Time: 04:17:38 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: First Engine Start Problem At 03:37 AM 12/27/2011, you wrote: >Bob, >I have had the Kitfox wiring completed for about 8 months now and I >used the new Z-16 schematic. I have most of my avionics on the E-Bus >and they have been working well since day one when I first flipped the switch. What is the total list of goodies on the e-bus? > A week ago the day came to do my first engine start. As it goes > with the Rotax 912uls, we purged the oil system then began turning > the prop looking for oil pressure. After turning it through several > times by hand we decided to then let the starter do the work. The > starter turned the engine over well, however, I was dismayed when > my whole panel of avionics went dead. I of course quit cranking and > began troubleshooting. It didn't take long to find that the > fuseable link off the Batt Contactor (heading to the E-Bus) burned > through. I went ahead and bypassed the link with 16 AWG and was > able to complete a successful first engine start. The guys that > were working with me asked me why that link was there...I did not > have a good answer for them. I do have the diode in place, yet I > assume a "spike" occurred when I turned the engine over. So...I am > now reluctant to put another fuseable link in place but have a > concern if there is still a problem that burned my link in the first place. >I am open to comments and suggestions. Any and all sorts of fault protection (links, fuses, breakers, etc) are there to protect wires. The idea of an e-bus is to power up electro-whizzies most useful for ALTERNATOR OUT EN ROUTE ENDURANCE while operating battery only. This alternate feed path goes around the battery contactor thus offering an opportunity to (1) eliminate battery contactor loads on the battery or (2) get a minimum list of useful goodies powered if the contactor or its control circuit fails. You didn't have a 'spike' . . . you had some level of LOAD that was greater than what the 22AWG link would carry. Having a list of goodies powered from the e-bus will give us the first clues as to why such a load existed. Bob . . . ________________________________ Message 4 _____________________________________ Time: 06:06:37 AM PST US From: Subject: AeroElectric-List: Dynon Skyview Airspeed Calibration... 12/27/2011 Hello Matt, You wrote: 1) "Are there Pitot line "attenuators" like for RF in coax?" Not pitot tube line attenuators, but both attenuators and augmentors in the form of wedges before or after the static port portion of the pitot - static system that can be used to tweak airspeed (and altitude) indications. 2) "But *fast* is a head scratcher. If there's no electronic configuration parameters to adjust, what do you do?" See this posting to the aeroelectric list for a more complete explanation of the use of wedges to adjust airspeed indications: http://www.matronics.com/searching/getmsg_script.cgi?INDEX=88398860?KEYS=static_port?LISTNAME=AeroElectric?HITNUMBER=9?SERIAL=0431117943?SHOWBUTTONS=YES A bit of search around in your Matronic's archive system on pitot static systems and airspeed, particularly any posting on this arena by Kevin Horton, will reveal a host of material for thought and action. 'OC' Baker Says: "The best investment we can make is the time and effort to gather and understand knowledge." ======================================================= Time: 07:43:08 PM PST US From: Matt Dralle Subject: AeroElectric-List: Dynon Skyview Airspeed Calibration... Dear Listers, I've been flying the new 10" Dynon Skyview in the RV-6 for a few weeks now and it seems like the airspeed is reading maybe 10mph fast. The GS always reads 10mph or more slower than the True airspeed, no matter which way I fly with respect to the current wind. Looking through the configuration options on the Skyview, I'm not seeing parameters to calibrate the airspeed. If the airspeed were *slow* compared to the GS, I could envision making adjustments to the Pitot tube to get it in better alignment with slipstream. But *fast* is a head scratcher. If there's no electronic configuration parameters to adjust, what do you do? Are there Pitot line "attenuators" like for RF in coax? ;-) Matt - Matt "Red Dawg" Dralle ________________________________ Message 5 _____________________________________ Time: 06:14:39 AM PST US From: "ROGER & JEAN CURTIS" Subject: RE: AeroElectric-List: First Engine Start Problem You didn't have a 'spike' . . . you had some level of LOAD that was greater than what the 22AWG link would carry. Having a list of goodies powered from the e-bus will give us the first clues as to why such a load existed. Bob . . . Since this is a new wiring installation, you may want to check your wiring again. Especially look to make sure that you do not somehow have starter current through your fusible link. Roger ________________________________ Message 6 _____________________________________ Time: 06:51:03 AM PST US From: Dan Billingsley Subject: Re: AeroElectric-List: First Engine Start Problem Thanks for the quick reply. I will be going to the airport today and take i nventory of the e-bus goodies. I understand and accept that this could be a n over-Load problem so I may need to transfer a couple things to the main b us. What troubles me is I have had this E-bus circuit working many times wi th everything turned on sometimes for 5 to 10 minutes without a hitch. Will start with a current tally and get back.=0ADan=0A=0A=0A=0A>_______________ _________________=0A> From: "Robert L. Nuckolls, III" =0A>To: aeroelectric-list@matronics.com =0A>Sent: Tuesday, Decemb er 27, 2011 5:14 AM=0A>Subject: Re: AeroElectric-List: First Engine Start P , III" =0A>=0A>At 03:37 AM 12/27/2011, you w rote:=0A>> Bob,=0A>> I have had the Kitfox wiring completed for about 8 mon ths now and I used the new Z-16 schematic. I have most of my avionics on th e E-Bus and they have been working well since day one when I first flipped the switch.=0A>=0A>- What is the total list of goodies on the e-bus?=0A> =0A>=0A>>- A week ago the day came to do my first engine start. As it goe s with the Rotax 912uls, we purged the oil system then began turning the pr op looking for oil pressure. After turning it through several times by hand we decided to then let the starter do the work. The starter turned the eng ine over well, however, I was dismayed when my whole panel of avionics went dead. I of course quit cranking and began troubleshooting. It didn't take long to find that the fuseable link off the Batt Contactor (heading to the E-Bus) burned through. I went ahead and bypassed the link with 16 AWG and w as able to complete a successful first engine start. The guys that were wor king with me asked me why that link was there...I did not have a good answe r for them. I do have the diode in place, yet I assume a "spike" occurred w hen I turned the engine over. So...I am now reluctant to put another fuseab le link in place but have a concern if there is still a problem that burned my link in the first place.=0A>> I am open to comments and suggestions.=0A >=0A>- Any and all sorts of fault protection (links,=0A>- fuses, brea kers, etc) are there to protect wires.=0A>- The idea of an e-bus is to p ower up electro-whizzies=0A>- most useful for ALTERNATOR OUT EN ROUTE EN DURANCE=0A>- while operating battery only. This alternate feed=0A>- p ath goes around the battery contactor thus offering=0A>- an opportunity to (1) eliminate battery contactor loads=0A>- on the battery or (2) get a minimum list of useful goodies=0A>- powered if the contactor or its co ntrol circuit fails.=0A>=0A>- You didn't have a 'spike' . . . you had so me level=0A>- of LOAD that was greater than what the 22AWG link=0A>- would carry. Having a list of goodies powered from the=0A>- e-bus will g ive us the first clues as to why such=0A>- a load existed.=0A>=0A>=0A> =======================0A>=0A> =0A>=0A>=0A>=0A> ________________________________ Message 7 _____________________________________ Time: 07:05:00 AM PST US From: "Valovich, Paul" Subject: Re: AeroElectric-List: Garmin 696 Data Out It's been a while but I think you have to use the serial port, not the data port. I think I ended up splitting the serial port output to my AFS 4500 and ADI II autopilot. ________________________________ Message 8 _____________________________________ Time: 07:14:39 AM PST US Subject: AeroElectric-List: Re: Dynon Skyview Airspeed Calibration... From: "racerjerry" If the airspeed is reading too HIGH, a quick & dirty solution is to install a controlled leak in the pitot system. Install a T in the pitot line and use the third port as a drilled jet to vent to cabin air. Begin with a #80 drill bit and open up. For calibration, extend the new line (plastic tubing) into the cockpit so your co-pilot can make adjustments in flight. -------- Jerry King Read this topic online here: http://forums.matronics.com/viewtopic.php?p=361733#361733 ________________________________ Message 9 _____________________________________ Time: 07:19:41 AM PST US From: paul wilson Subject: Re: AeroElectric-List: Dynon Skyview Airspeed Calibration... Pitot is not an issue since it is pretty insensitive to angle of attack. A quick check in just about any gas dynamics text will tell you error vs angle of attack. My memory is bad, but its pretty hard to get much of an error due to angle. Static location can be an issue. The text book pitot static probe had many static ports and one dynamic port. Paul =========== At 08:39 PM 12/26/2011, you wrote: > >Dear Listers, > >I've been flying the new 10" Dynon Skyview in the RV-6 for a few >weeks now and it seems like the airspeed is reading maybe 10mph >fast. The GS always reads 10mph or more slower than the True >airspeed, no matter which way I fly with respect to the current >wind. Looking through the configuration options on the Skyview, I'm >not seeing parameters to calibrate the airspeed. If the airspeed >were *slow* compared to the GS, I could envision making adjustments >to the Pitot tube to get it in better alignment with >slipstream. But *fast* is a head scratcher. If there's no >electronic configuration parameters to adjust, what do you do? Are >there Pitot line "attenuators" like for RF in coax? ;-) > >Matt > >- >Matt "Red Dawg" Dralle > >RV-8 #82880 N998RV "Ruby Vixen" >http://www.mattsrv8.com - Matt's Complete RV-8 Construction Log >http://www.mattsrv8.com/Mishap - Landing Mishap Rebuild Log >http://www.youtube.com/MattsRV8 - Matt's RV-8 HDTV YouTube Channel >Status: 170+ Hours TTSN - Rebuilding Fuselage After Landing Mishap... > >RV-6 #20916 N360EM "The Flyer" >http://www.mattsrv6.com - Matt's RV-6 Revitalization Log >Status: 42+ Hours Since Purchase - Upgrades Complete; Now In Full Flyer Mode > > ________________________________ Message 10 ____________________________________ Time: 07:19:46 AM PST US From: Tim Perry Subject: Re: AeroElectric-List: First Engine Start Problem Sound like you have a loose connection. When you cranked the engine somethin g that was not touching now was. There is often a lot of movement with the e ngine start you don't get with it just sitting there. And during your troub leshooting you might have moved the offending conbection where it no longer i s making contact. I have had this type of problem before and it really suck s when it happens during flight, but best to have a good breaker or fuse blo w than a fire.... Tim Sent from my iPhone On Dec 27, 2011, at 9:46 AM, Dan Billingsley wro te: > Thanks for the quick reply. I will be going to the airport today and take i nventory of the e-bus goodies. I understand and accept that this could be an over-Load problem so I may need to transfer a couple things to the main bus . What troubles me is I have had this E-bus circuit working many times with e verything turned on sometimes for 5 to 10 minutes without a hitch. Will star t with a current tally and get back. > Dan > > From: "Robert L. Nuckolls, III" > To: aeroelectric-list@matronics.com > Sent: Tuesday, December 27, 2011 5:14 AM > Subject: Re: AeroElectric-List: First Engine Start Problem > ls.bob@aeroelectric.com> > > At 03:37 AM 12/27/2011, you wrote: > > Bob, > > I have had the Kitfox wiring completed for about 8 months now and I used the new Z-16 schematic. I have most of my avionics on the E-Bus and they ha ve been working well since day one when I first flipped the switch. > > What is the total list of goodies on the e-bus? > > > > A week ago the day came to do my first engine start. As it goes with th e Rotax 912uls, we purged the oil system then began turning the prop looking for oil pressure. After turning it through several times by hand we decided to then let the starter do the work. The starter turned the engine over wel l, however, I was dismayed when my whole panel of avionics went dead. I of c ourse quit cranking and began troubleshooting. It didn't take long to find t hat the fuseable link off the Batt Contactor (heading to the E-Bus) burned t hrough. I went ahead and bypassed the link with 16 AWG and was able to compl ete a successful first engine start. The guys that were working with me aske d me why that link was there...I did not have a good answer for them. I do h ave the diode in place, yet I assume a "spike" occurred when I turned the en gine over. So...I am now reluctant to put another fuseable link in place but have a concern if there is still a problem that burned my link in the first place. > > I am open to comments and suggestions. > > Any and all sorts of fault protection (links, > fuses, breakers, etc) are there to protect wires. > The idea of an e-bus is to power up electro-whizzies > most useful for ALTERNATOR OUT EN ROUTE ENDURANCE > while operating battery only. This alternate feed > path goes around the battery contactor thus offering > an opportunity to (1) eliminate battery contactor loads > on the battery or (2) get a minimum list of useful goodies > powered if the contactor or its control circuit fails. > > You didn't have a 'spike' . . . you had some level > of LOAD that was greater than what the 22AWG link > would carry. Having a list of goodies powered from the > e-bus will give us the first clues as to why such > a load existe==================== ====www.builders -Matt - The AeroElectri c-List Email Forum -http://www.matronics.com/Navigator?Aersp; - MATRONICS WEB FORUMS - > sp; --> http://ww=================== === > > > > > > > ========================== ========= ========================== ========= ========================== ========= ========================== ========= ========================== ========= > ________________________________ Message 11 ____________________________________ Time: 07:33:30 AM PST US From: "n801bh@netzero.com" Subject: Re: AeroElectric-List: Re: Dynon Skyview Airspeed Calibration... That is a viable fix.... Another easy and adjustable way is to go to a p et supply store and buy a small needle valve they sell for aquariums and plumb it in the line. That way you can dial in the exact bleed off. do not archive electric-list@matronics.com Subject: AeroElectric-List: Re: Dynon Skyview Airspeed Calibration... y.us> If the airspeed is reading too HIGH, a quick & dirty solution is to inst all a controlled leak in the pitot system. Install a =9CT=9D in the pitot line and use the third port as a drilled jet to vent to ca bin air. Begin with a #80 drill bit and open up. For calibration, exte nd the new line (plastic tubing) into the cockpit so your co-pilot can m ake adjustments in flight. -------- Jerry King Read this topic online here: http://forums.matronics.com/viewtopic.php?p=361733#361733 ======================== =========== ======================== =========== ======================== =========== ======================== =========== ======================== =========== ____________________________________________________________ 53 Year Old Mom Looks 33 The Stunning Results of Her Wrinkle Trick Has Botox Doctors Worried http://thirdpartyoffers.netzero.net/TGL3241/4ef9e482a5b932591f91st01vuc ________________________________ Message 12 ____________________________________ Time: 07:38:29 AM PST US Subject: AeroElectric-List: Re: First Engine Start Problem From: "zodiac601" My guess is an overloaded e bus. When you cranked, the voltage dropped and the amps of everything went up. watts = volts x amps. If the battery voltage dropped 20% during cranking, then the amperage of everything went up 20% as well. Read this topic online here: http://forums.matronics.com/viewtopic.php?p=361739#361739 ________________________________ Message 13 ____________________________________ Time: 08:34:08 AM PST US From: "The Kuffels" Subject: Re: AeroElectric-List: Dynon Skyview Airspeed Calibration... Matt, Agree with others the symptoms indicate a static problem, specifically the location is producing a vacuum when moving. While introducing a "controlled leak" in the pitot side might fix the airspeed error, probably at only one airspeed, it wouldn't fix the altitude error also produced by static error. Two very simple things you can do to confirm the problem and start toward a solution. First on takeoff set the altimeter to an exact division. Note as you speed up and rotate if the altitude changes, even a little. Higher altitude implies dynamic vacuum at the static port(s) which will produce the effect you describe, lower altitude means dynamic pressure. As a test, tape a wedge, or even a block such as a short piece or two of tongue depressor, behind the port(s). If your error decreases you are on the right track and set for a little cut and try with wedge size and placement. Before starting be sure to have accurate error measurements. Use the spreadsheet mentioned by others to get wind independent actual true airspeeds. Or you are welcome to the spreadsheet I developed from the same formula with 4 leg input. The 4th leg provides redundant information to indicate the quality of the input data. Tom Kuffel, CFI EAA Flight Advisor ________________________________ Message 14 ____________________________________ Time: 08:51:40 AM PST US Subject: Re: AeroElectric-List: Re: Dynon Skyview Airspeed Calibration... From: Kevin Horton On 2011-12-27, at 11:12 , racerjerry wrote: > > If the airspeed is reading too HIGH, a quick & dirty solution is to install a controlled leak in the pitot system. Install a T in the pitot line and use the third port as a drilled jet to vent to cabin air. Begin with a #80 drill bit and open up. For calibration, extend the new line (plastic tubing) into the cockpit so your co-pilot can make adjustments in flight. If the airspeed is reading too, it is quite likely a problem with the static system. This could be a static system leak, or a poorly designed or located static port. Errors in the static system will affect both airspeed and altitude, so it is much better to find and fix the static source problem than it is to create a pitot leak too. If you were to fiddle with the pitot system to fix the ASI indication (or provide ASI adjustments, as some EFIS systems allow), you would still have errors in the altimeter, and these can be safety of flight issues. The TCAS systems on larger aircraft provide guidance to avoid collision with you based on whatever altitude is reported by your transponder. If you have static system errors, the TCAS system may be giving commands that increase the risk of collision. Static system leaks on RVs often produce ASIs that read about 10 kt too high, so the first thing to do is a static system leak check. Another common problem is flush mounted static ports on RVs, but this typically leads to ASIs reading too low. -- Kevin Horton RV-8 Ottawa, Canada http://www.kilohotel.com/rv8 ________________________________ Message 15 ____________________________________ Time: 08:59:39 AM PST US From: bnelson79@charter.net Subject: Re: AeroElectric-List: Relays Bob, In the original 1998 Rotax Installation Manual the schematic didn't show anything fancy. But the newest incarnation (May 2009) has both a starter relay and a battery relay. I've talked to at least 2 Rotax techs, the Rans tech, my own mechanic, as well as others and everyone seems to say something different. I think I've decided to go with the latest schematic which has a 5 A and a 50 A fuse/C.B. in the external alternator circuit as well as a DPST master switch that connects the 5 A line from the IG connection on the alternator to the battery relay. There is also a 25 A fuse/C.B. in the R, B+, C lines from the regulator/rectifier in the internal alternator circuit. Both alternators run at the same time then, all the time, although the 5 A C.B. will be switched so I can shut down the external alternator if I want to. I assume there is one line coming out of the external alt. circuit and another from the internal circuit that both connect to the consumers bus. Is this correct with both running at the same time? Any comments on any of these issues will be appreciated. Bill On Mon, Dec 26, 2011 at 7:01 PM, Robert L. Nuckolls, III wrote: > > > At 10:13 PM 12/25/2011, you wrote: >> >> >> What is the difference between a battery relay and a starter relay? I >> have a Rans S12S and the circuit diagram for the Rotax 912ULS engine >> shows both. But I just got the plane and it only has what I think is >> a starter relay with the rotary starter switch and a simple SPST >> master switch. Do I need to add the battery relay? > > Probably not. You've got a day-vfr-fair weather > machine with few incentives for adding lots of > 'conveniences'. The Piper Tri-Pacer in which I took early > flying lessons had a battery switch and a starter > push-button. No relays at all. > > The FUNCTIONALITY for the two devices is very > different. The battery switch/contactor is designed > to use a minimum of power and is expected to SWITCH > rather light loads while being able to CARRY the > occasional starter current. > > The starter contactor needs to SWITCH large inrush > loads without welding contacts. Power drain is not > an issue because its operating duty cycle is very > low . . . seconds per flight cycle. Hence, the starter > switch/contactor is designed for the more demanding > service as a control device. > > If what you have has been vetted by folks who > have been-there-done-that . . . there's no compelling > rationale for changing anything. If they become > troublesome, get with us here on the List and we'll > help you craft a more robust alternative. > > > Bob . . . ________________________________ Message 16 ____________________________________ Time: 09:22:20 AM PST US From: "Gerry van Dyk" Subject: RE: AeroElectric-List: Dynon Skyview Airspeed Calibration... Matt, I've got a couple of thoughts: The pitot / static system depends on the static port being true ambient pressure, which is actually pretty difficult to achieve in airflow. If you've got the port(s) in a spot that generates a slight positive pressure on the static side you will de-calibrate the airspeed to the low side, if there's negative pressure at the port airspeed will read high. On the C172SP I rent there's a 1/8" high lip on the fitting right beside the static hole. As the lip is at an angle to airflow, I presume they dial in the static system by rotating the fitting so the angle gives the correct pressure at the port for a specific speed range. I've read somewhere (perhaps the Bingelis books) about making adjustments to the static port by laying strips of tape in front of or behind the port. As an example, the area in front of the windshield on a stock car is a high pressure area where they take the induction to the engine, I would suggest laying down a few thicknesses of tape behind the port to start. Then again if your port is in an area of laminar flow, tripping the flow in front of the port may have the same effect. I believe once you have a modification that works you can make a permanent 'fix' that would be more efficient than a bleed port in the line. Hope this helps. Gerry -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Matt Dralle Sent: December 26, 2011 8:39 PM Subject: AeroElectric-List: Dynon Skyview Airspeed Calibration... Dear Listers, I've been flying the new 10" Dynon Skyview in the RV-6 for a few weeks now and it seems like the airspeed is reading maybe 10mph fast. The GS always reads 10mph or more slower than the True airspeed, no matter which way I fly with respect to the current wind. Looking through the configuration options on the Skyview, I'm not seeing parameters to calibrate the airspeed. If the airspeed were *slow* compared to the GS, I could envision making adjustments to the Pitot tube to get it in better alignment with slipstream. But *fast* is a head scratcher. If there's no electronic configuration parameters to adjust, what do you do? Are there Pitot line "attenuators" like for RF in coax? ;-) Matt - Matt "Red Dawg" Dralle RV-8 #82880 N998RV "Ruby Vixen" http://www.mattsrv8.com - Matt's Complete RV-8 Construction Log http://www.mattsrv8.com/Mishap - Landing Mishap Rebuild Log http://www.youtube.com/MattsRV8 - Matt's RV-8 HDTV YouTube Channel Status: 170+ Hours TTSN - Rebuilding Fuselage After Landing Mishap... RV-6 #20916 N360EM "The Flyer" http://www.mattsrv6.com - Matt's RV-6 Revitalization Log Status: 42+ Hours Since Purchase - Upgrades Complete; Now In Full Flyer Mode ________________________________ Message 17 ____________________________________ Time: 10:26:56 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Re: First Engine Start Problem At 09:35 AM 12/27/2011, you wrote: > >My guess is an overloaded e bus. When you cranked, the voltage >dropped and the amps of everything went up. watts = volts x amps. > >If the battery voltage dropped 20% during cranking, then the >amperage of everything went up 20% as well. For the vast majority of electro-whizzies, current draw does not go up and input voltage goes down. Modern avionics with switchmode power supplies are 'constant power' systems but even then, the increase is not THAT profound for the duration of a cranking cycle. It takes a LOT more current to fuse a 22AWG wire than you might suppose. See: http://aeroelectric.com/Pictures/Wire/22AWG_20A.pdf Current ratings for wire is bounded by INSULATION performance, not COPPER performance. If he fused a 22AWG link, something rather profound occurred. Bob . . . ________________________________ Message 18 ____________________________________ Time: 10:27:58 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Relays At 10:56 AM 12/27/2011, you wrote: > >Bob, >In the original 1998 Rotax Installation Manual the schematic didn't >show anything fancy. But the newest incarnation (May 2009) has both >a starter relay and a battery relay. I've talked to at least 2 >Rotax techs, the Rans tech, my own mechanic, as well as others and >everyone seems to say something different. I think I've decided to >go with the latest schematic which has a 5 A and a 50 A fuse/C.B. in >the external alternator circuit as well as a DPST master switch that >connects the 5 A line from the IG connection on the alternator to >the battery relay. There is also a 25 A fuse/C.B. in the R, B+, C >lines from the regulator/rectifier in the internal alternator >circuit. Both alternators run at the same time then, all the time, >although the 5 A C.B. will be switched so I can shut down the >external alternator if I want to. I assume there is one line coming >out of the external alt. circuit and another from the internal >circuit that both connect to the consumers bus. Is this correct >with both running at the same time? >Any comments on any of these issues will be appreciated. Forgive me but a schematic is many times more lucid than a verbal description. Can you send/post/link a copy of the diagram that strikes your fancy? Bob . . . ________________________________ Message 19 ____________________________________ Time: 10:29:53 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: First Engine Start Problem At 08:46 AM 12/27/2011, you wrote: >Thanks for the quick reply. I will be going to the airport today and >take inventory of the e-bus goodies. I understand and accept that >this could be an over-Load problem so I may need to transfer a >couple things to the main bus. What troubles me is I have had this >E-bus circuit working many times with everything turned on sometimes >for 5 to 10 minutes without a hitch. Will start with a current tally >and get back. In particular, do you have any loads that are not generally described in the suggested list of endurance goodies I've written about? Is your starter system dependent upon e-bus supply of energy in any way? Bob . . . ________________________________ Message 20 ____________________________________ Time: 01:39:32 PM PST US From: "Bill Bradburry" Subject: RE: AeroElectric-List: Re: Dynon Skyview Airspeed Calibration... If you build in a leak in the system, I doubt that you will ever pass your biannual transponder check. Just something to consider... Bill B -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Kevin Horton Sent: Tuesday, December 27, 2011 11:46 AM Subject: Re: AeroElectric-List: Re: Dynon Skyview Airspeed Calibration... On 2011-12-27, at 11:12 , racerjerry wrote: > > If the airspeed is reading too HIGH, a quick & dirty solution is to install a controlled leak in the pitot system. Install a "T" in the pitot line and use the third port as a drilled jet to vent to cabin air. Begin with a #80 drill bit and open up. For calibration, extend the new line (plastic tubing) into the cockpit so your co-pilot can make adjustments in flight. If the airspeed is reading too, it is quite likely a problem with the static system. This could be a static system leak, or a poorly designed or located static port. Errors in the static system will affect both airspeed and altitude, so it is much better to find and fix the static source problem than it is to create a pitot leak too. If you were to fiddle with the pitot system to fix the ASI indication (or provide ASI adjustments, as some EFIS systems allow), you would still have errors in the altimeter, and these can be safety of flight issues. The TCAS systems on larger aircraft provide guidance to avoid collision with you based on whatever altitude is reported by your transponder. If you have static system errors, the TCAS system may be giving commands that increase the risk of collision. Static system leaks on RVs often produce ASIs that read about 10 kt too high, so the first thing to do is a static system leak check. Another common problem is flush mounted static ports on RVs, but this typically leads to ASIs reading too low. -- Kevin Horton RV-8 Ottawa, Canada http://www.kilohotel.com/rv8 ________________________________ Message 21 ____________________________________ Time: 05:44:59 PM PST US From: Dan Billingsley Subject: Re: AeroElectric-List: First Engine Start Problem ________________________________ From: "Robert L. Nuckolls, III" Sent: Tue, December 27, 2011 11:27:05 AM Subject: Re: AeroElectric-List: First Engine Start Problem At 08:46 AM 12/27/2011, you wrote: Thanks for the quick reply. I will be going to the airport today and take inventory of the e-bus goodies. I understand and accept that this could be an over-Load problem so I may need to transfer a couple things to the main bus. What troubles me is I have had this E-bus circuit working many times with everything turned on sometimes for 5 to 10 minutes without a hitch. Will start with a current tally and get back. In particular, do you have any loads that are not generally described in the suggested list of endurance goodies I've written about? Is your starter system dependent upon e-bus supply of energy in any way? No, the starter system is drawn off the main buss. I was not able to take a tally on the goodies today but it is in the cards for tomorrow. I will get back the info to the list as soon as I round it up. I will say that there are quite a few things on the E-Bus as compared to the Main. Doing a tally on the amps drawn when all is on at the E-Bus is something I neglected to do, so I am quite interested in figuring it out. Thanks all for the comments and suggestions. Dan Bob . . . ________________________________ Message 22 ____________________________________ Time: 08:58:50 PM PST US From: "Bill Nelson" Subject: RE: AeroElectric-List: Relays Picture #1 is the old system that approximates mine, though there are some additional C.B. switches and fuses in some lines. #2 is what I would like to go with. The DPST Master Switch would be replaced with a SPST 5 Amp C.B. switch and 16 would be a simple Master Switch connected to the battery relay. Any thoughts, suggestions, or warnings would be appreciated. Bill -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Robert L. Nuckolls, III Sent: Tuesday, December 27, 2011 10:25 AM Subject: Re: AeroElectric-List: Relays --> At 10:56 AM 12/27/2011, you wrote: > >Bob, >In the original 1998 Rotax Installation Manual the schematic didn't >show anything fancy. But the newest incarnation (May 2009) has both a >starter relay and a battery relay. I've talked to at least 2 Rotax >techs, the Rans tech, my own mechanic, as well as others and everyone >seems to say something different. I think I've decided to go with the >latest schematic which has a 5 A and a 50 A fuse/C.B. in the external >alternator circuit as well as a DPST master switch that connects the 5 >A line from the IG connection on the alternator to the battery relay. >There is also a 25 A fuse/C.B. in the R, B+, C lines from the >regulator/rectifier in the internal alternator circuit. Both >alternators run at the same time then, all the time, although the 5 A >C.B. will be switched so I can shut down the external alternator if I >want to. I assume there is one line coming out of the external alt. >circuit and another from the internal circuit that both connect to the >consumers bus. Is this correct with both running at the same time? >Any comments on any of these issues will be appreciated. Forgive me but a schematic is many times more lucid than a verbal description. Can you send/post/link a copy of the diagram that strikes your fancy? Bob . . . ________________________________ Message 23 ____________________________________ Time: 09:16:40 PM PST US From: Matt Dralle Subject: AeroElectric-List: Re: Dynon Skyview Airspeed Calibration... At 07:39 PM 12/26/2011 Monday, Matt Dralle wrote: >Dear Listers, > >I've been flying the new 10" Dynon Skyview in the RV-6 for a few weeks now and it seems like the airspeed is reading maybe 10mph fast. The GS always reads 10mph or more slower than the True airspeed, no matter which way I fly with respect to the current wind. Looking through the configuration options on the Skyview, I'm not seeing parameters to calibrate the airspeed. If the airspeed were *slow* compared to the GS, I could envision making adjustments to the Pitot tube to get it in better alignment with slipstream. But *fast* is a head scratcher. If there's no electronic configuration parameters to adjust, what do you do? Are there Pitot line "attenuators" like for RF in coax? ;-) > >Matt Listers, Thank you for all the great suggestions on resolving this airspeed issue! I took a look at the static ports on the RV-6 today and found that they are done using a flush head screw with a hole drilled in the center on either side of the fuselage. They do *not* protrude from the side of the plane at all. They are totally flush (see attached picture). Just for fun, I whipped up a couple of quick test deals using a 3/16" washer and some electrical tape. I poked a 1/16" hole in the center of the tape and then put the washer centered over the static ports on both sides of the fuselage (see attached pictures). Then, I went flying on this beautiful December 27 day in California! I didn't have time to do any real scientific multi-leg testing, but I was amazed that the True Airspeed is now falling in a much more believable range compared to the GPS-derived ground speed. On one cross-country leg, I had an exactly 90 degree crosswind component and the True Airspeed and GPS Ground Speed were tracking exactly the same. Yahoo! Obviously I need to do some additional, more scientific measurements and probably come up with a slightly more "permanent" washer arrangement, but the early returns are very promising! :-) Thanks again for all the great feedback! Matt - Matt "Red Dawg" Dralle RV-8 #82880 N998RV "Ruby Vixen" http://www.mattsrv8.com - Matt's Complete RV-8 Construction Log http://www.mattsrv8.com/Mishap - Landing Mishap Rebuild Log http://www.youtube.com/MattsRV8 - Matt's RV-8 HDTV YouTube Channel Status: 170+ Hours TTSN - Rebuilding Fuselage After Landing Mishap... RV-6 #20916 N360EM "The Flyer" http://www.mattsrv6.com - Matt's RV-6 Revitalization Log Status: 42+ Hours Since Purchase - Upgrades Complete; Now In Full Flyer Mode ________________________________ Message 24 ____________________________________ Time: 10:36:02 PM PST US From: Matt Dralle Subject: AeroElectric-List: Dynon Skyview vs. GRT HX EFIS... >At 09:47 PM 12/27/2011 Tuesday, you wrote: >I have looked at the Dynon stuff up at Arlington Air Show the past two years >and really like the looks of them. They added autopilot and said last year >that they were about to announce communications added to their system. A >single 10" screen to do everything would be pretty easy to install learn to >operate. Mostly Dynon looks best in the magazines. I guess you get used to >any of them or they would not all still be in business. >Pete I have a Dynon 10" Skyview in the RV-6: http://www.mattsrv6.com/users/display_log.php?user=MattsRV6&project 43&category=0&log=138164&row=45 http://www.mattsrv6.com/users/display_log.php?user=MattsRV6&project 43&category=0&log=138163&row=46 and a triple GRT HX setup in the RV-8: http://www.mattsrv8.com/users/display_log.php?user=MattsRV8&project=638&category=2973&log'376&row=134 http://www.mattsrv8.com/users/display_log.php?user=MattsRV8&project=638&category=2973&log'375&row=135 I've flown the GRT HX setup about 170 hours and the Dynon Skyview system about 45 hours now. Which do I prefer? That's a tough call. There are parts about each system that I like a lot... The installation and configuration of the Dynon is easier. Instructions are also better. The network cable interconnect system that Dynon uses (I think it is just RS485, but it works well) is also a no-brainer to install. Their display (PFD/Engine/Map) are definitely very pretty and demo well. The GRT is a little harder to get installed, the manual is a little sketchy in places and there are a LOT of configuration options that can seem daunting at first. BUT, there is power and utility in those options. If you use them to your advantage, you can probably do more, better on the GRT compared to the Dynon. The displays on the GRT don't have the "3D-y", "Windows-y" look to them. BUT, I think I'm preferring that at this point. Doing a scan on the GRT looking for something out of the ordinary is quicker and more accurate. I also like the PFD layout and operation on the GRT better. It feels more "accurate" and "believable" to me for some reason. I never quite "trust" what I'm seeing on the Dynon for some reason and I don't know why. Maybe I just need more time on the Dynon. So, the Dynon has it for Installation and Configuation, but the GRT has it for Operation and Presentation as far as I'm concerned. If I was building a new plane, I think that I would probably go with the GRT. But its a close race. I really like the Dynon system too. I guess I'm saying if you're in the market for a full-featured EFIS system, give GRT and Dynon both very close look before you make your selection. In my opinion, it comes down to personal preferences in a few select areas on which way to go. Both systems are top notch. BTW, Dynon's autopilot add-on for the Skyview which I have in the RV-6 works well. Its a good autopilot that does the job. The servos are the same as with the TruTrak system. In the RV-8, I have the TruTrak Digiflight II VSGV system. The TruTrak is a smoother, more accurate autopilot in my opinion, and I would go that route again. But, it also costs quite a bit more than just adding servos to the Dynon or GRT. $.02 - Matt "Red Dawg" Dralle RV-8 #82880 N998RV "Ruby Vixen" http://www.mattsrv8.com - Matt's Complete RV-8 Construction Log http://www.mattsrv8.com/Mishap - Landing Mishap Rebuild Log http://www.youtube.com/MattsRV8 - Matt's RV-8 HDTV YouTube Channel Status: 170+ Hours TTSN - Rebuilding Fuselage After Landing Mishap... RV-6 #20916 N360EM "The Flyer" http://www.mattsrv6.com - Matt's RV-6 Revitalization Log Status: 42+ Hours Since Purchase - Upgrades Complete; Now In Full Flyer Mode ------------------------------------------------------------------------------------- Other Matronics Email List Services ------------------------------------------------------------------------------------- Post A New Message aeroelectric-list@matronics.com UN/SUBSCRIBE http://www.matronics.com/subscription List FAQ http://www.matronics.com/FAQ/AeroElectric-List.htm Web Forum Interface To Lists http://forums.matronics.com Matronics List Wiki http://wiki.matronics.com Full Archive Search Engine http://www.matronics.com/search 7-Day List Browse http://www.matronics.com/browse/aeroelectric-list Browse Digests http://www.matronics.com/digest/aeroelectric-list Browse Other Lists http://www.matronics.com/browse Live Online Chat! http://www.matronics.com/chat Archive Downloading http://www.matronics.com/archives Photo Share http://www.matronics.com/photoshare Other Email Lists http://www.matronics.com/emaillists Contributions http://www.matronics.com/contribution ------------------------------------------------------------------------------------- These Email List Services are sponsored solely by Matronics and through the generous Contributions of its members.