---------------------------------------------------------- AeroElectric-List Digest Archive --- Total Messages Posted Wed 03/17/04: 23 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 12:55 AM - Re: Re: AeroElectric-List Digest: 17 Msgs - 03/15/04 (GMC) 2. 04:03 AM - Preflight check of SD-8? (Kevin Horton) 3. 04:58 AM - Re: Re: AeroElectric-List Digest: 17 Msgs - 03/15/04 (Dave von Linsowe) 4. 05:12 AM - Coax (Mark Banus) 5. 05:22 AM - Re: AeroElectric-List Digest: 41 Msgs - 03/16/04 () 6. 05:42 AM - Re: Coax (Robert L. Nuckolls, III) 7. 06:43 AM - Re: annunciator lights (Jeff Hildebrand) 8. 07:28 AM - Re: Preflight check of SD-8? (Ken Harrill) 9. 07:39 AM - Re: annunciator lights (flyv35b) 10. 07:41 AM - Re: Coax related (DWENSING@aol.com) 11. 07:51 AM - Re: Preflight check of SD-8? (Matt Prather) 12. 08:07 AM - Prop Stopped Best Glide (Speedy11@aol.com) 13. 08:41 AM - Re: annunciator lights (LarryRobertHelming) 14. 09:23 AM - Re: Prop Stopped Best Glide (Matt Prather) 15. 09:27 AM - Re: Preflight check of SD-8? (Matt Prather) 16. 10:03 AM - Re: Preflight check of SD-8? (Ken Harrill) 17. 11:05 AM - Aeroelectric Digest (Hebeard2@aol.com) 18. 04:55 PM - SEC: UNCLASSIFIED - STOPPING THE PROP IN AN RV (Francis, David CMDR) 19. 05:09 PM - Re: bench checking, what to watch out for (CardinalNSB@aol.com) 20. 05:13 PM - Control Stick Switch Overrides (PeterHunt1@aol.com) 21. 05:32 PM - Re: SEC: UNCLASSIFIED - STOPPING THE PROP IN AN RV (Ed Anderson) 22. 06:14 PM - Re: Control Stick Switch Overrides (Robert McCallum) 23. 06:24 PM - Re: SEC: UNCLASSIFIED - STOPPING THE PROP IN (Kevin Horton) ________________________________ Message 1 _____________________________________ Time: 12:55:22 AM PST US From: "GMC" Subject: RE: AeroElectric-List: Re: AeroElectric-List Digest: 17 Msgs - 03/15/04 --> AeroElectric-List message posted by: "GMC" Probably the best information available is the CAFE Foundation report on Steve Barnards RV-6A done in 1993 and found at www.cafefoundation.org/research.htm looks like 106 MPH for best glide and 81 MPH for least sink rate. George in Langley > Alex, > What is best glide speed (IAS) in your RV-6A? Do you have to > spin the prop > again to attain best glide speed? Anyone have the best glide > speed for the > RV-8A? > Stan Sutterfield Warning: amateur advice ahead... Stan, I haven't a clue. Within reason, I think best glide speed is a little overrated. That being said, if my engine conks out I'll look for about 80 knots indicated. What I think is very important is the speed one has when on about a quarter mile final into the selected emergency landing zone, and how one deals with the transition from glide to flare to touchdown in their plane. The RV's will sink rapidly without power, and one needs to understand that without power (idle thrust as compared to engine drag) the flare will be much different. It is also important to understand how to get rid of excess altitude (slips, turns, etc.). Practicing power off landings is essential, which reminds me, I'm overdue for that. In an RV, good practice is to be something like 2000'agl when in upwind directly over the touchdown zone. This allows for a gentle, but continuous, 360 turn back around to touchdown. Alex Peterson ________________________________ Message 2 _____________________________________ Time: 04:03:27 AM PST US From: Kevin Horton Subject: AeroElectric-List: Preflight check of SD-8? --> AeroElectric-List message posted by: Kevin Horton I'm working on the checklists for my RV-8, and am wondering whether there are any potential issues around checking an SD-8 standby alternator right after engine start. I was considering starting the engine, then selecting the SD-8 ON to confirm a voltage rise, then selecting the SD-8 OFF and selecting the main alternator ON. Will the SD-8 have enough output to bring the voltage up even though the battery needs to be recharge? Are there any concerns about load dump issues when I select the SD-8 OFF while it is trying to charge the battery? It seems like the only other opportunity to check the SD-8 preflight would be to select the main alternator OFF during the runup, and check the SD-8 then. But that seems like it could trigger the load dump problems, unless the battery has been charged by then. I'll need the SD-8 as backup when I fly IFR, so I want a way to do a preflight check on it. What is the best way to do this? -- Kevin Horton RV-8 (finishing kit) Ottawa, Canada http://go.phpwebhosting.com/~khorton/rv8/ ________________________________ Message 3 _____________________________________ Time: 04:58:49 AM PST US From: "Dave von Linsowe" Subject: Re: AeroElectric-List: Re: AeroElectric-List Digest: 17 Msgs - 03/15/04 --> AeroElectric-List message posted by: "Dave von Linsowe" It should also be brought up that with a constant speed prop the glide performance with a wind milling prop can be significantly increased by pulling in more pitch. That is if the engine is still producing enough oil pressure to do so. The effect will be even more pronounced if you are turning a three bladed prop. It can be easily tested during a low idle glide by slowly cycling the prop. Dave RV-6 ----- Original Message ----- From: GMC To: aeroelectric-list@matronics.com Sent: Wednesday, March 17, 2004 3:56 AM Subject: RE: AeroElectric-List: Re: AeroElectric-List Digest: 17 Msgs - 03/15/04 --> AeroElectric-List message posted by: "GMC" Probably the best information available is the CAFE Foundation report on Steve Barnards RV-6A done in 1993 and found at www.cafefoundation.org/research.htm looks like 106 MPH for best glide and 81 MPH for least sink rate. George in Langley > Alex, > What is best glide speed (IAS) in your RV-6A? Do you have to > spin the prop > again to attain best glide speed? Anyone have the best glide > speed for the > RV-8A? > Stan Sutterfield Warning: amateur advice ahead... Stan, I haven't a clue. Within reason, I think best glide speed is a little overrated. That being said, if my engine conks out I'll look for about 80 knots indicated. What I think is very important is the speed one has when on about a quarter mile final into the selected emergency landing zone, and how one deals with the transition from glide to flare to touchdown in their plane. The RV's will sink rapidly without power, and one needs to understand that without power (idle thrust as compared to engine drag) the flare will be much different. It is also important to understand how to get rid of excess altitude (slips, turns, etc.). Practicing power off landings is essential, which reminds me, I'm overdue for that. In an RV, good practice is to be something like 2000'agl when in upwind directly over the touchdown zone. This allows for a gentle, but continuous, 360 turn back around to touchdown. Alex Peterson ________________________________ Message 4 _____________________________________ Time: 05:12:02 AM PST US From: "Mark Banus" Subject: AeroElectric-List: Coax --> AeroElectric-List message posted by: "Mark Banus" Bob, I am installing a Narco 890 DME (don't ask) and the installation manual (circa 1980) lists several RG numbers (58, 29, 223, 54, 8) that can be used depending on the length of the Coax. The criteria is "Maximum loss of 1.5 dB for the whole cable assembly". My cable will be between 6 and 8' depending on routing. Question: Is RG 400/142 the appropriate replacement Coax? What is the loss/foot? Thanks BTW, Great seminar in Groton. Mark Banus Glasair Super II FT Still Making dust in the garage ________________________________ Message 5 _____________________________________ Time: 05:22:18 AM PST US From: Subject: AeroElectric-List: Re: AeroElectric-List Digest: 41 Msgs - 03/16/04 --> AeroElectric-List message posted by: Can someone suggest a tool for crimpong the alligator type pins for old Narco 11's? I think they were also used on some Kings. Thanks. ________________________________ Message 6 _____________________________________ Time: 05:42:56 AM PST US From: "Robert L. Nuckolls, III" Subject: Re: AeroElectric-List: Coax --> AeroElectric-List message posted by: "Robert L. Nuckolls, III" At 08:12 AM 3/17/2004 -0500, you wrote: >--> AeroElectric-List message posted by: "Mark Banus" > >Bob, I am installing a Narco 890 DME (don't ask) and the installation >manual (circa 1980) lists several RG numbers (58, 29, 223, 54, 8) that can >be used depending on the length of the Coax. The criteria is >"Maximum loss of 1.5 dB for the whole cable assembly". >My cable will be between 6 and 8' depending on routing. Question: Is RG >400/142 the appropriate replacement Coax? What is the loss/foot? RG-400 (stranded center conductor) or RG-142 (solid) would be an excellent substitute for RG-58 (WWII vintage stuff). These modern coaxes will present 20 db/hundred feet at DME frequencies so 10 feet will be 2.0 dB and 7.5 feet would be 1.5 dB. RG-58 would be about 26 dB per hundred so you couldn't make the 1.5 dB requirement in 6' of coax. Bob . . . ________________________________ Message 7 _____________________________________ Time: 06:43:41 AM PST US From: "Jeff Hildebrand" Subject: RE: AeroElectric-List: annunciator lights --> AeroElectric-List message posted by: "Jeff Hildebrand" I don't think you can get much of a deal on these lights; we bought ours from a dealer in Canada for about $32 each. It generally doesn't make much sense for the shipping, but if you are buying 10 or 16 of them, you could save some money. The cost is insane, but other than these AML series, it's hard to find a real pro looking annunciator. Jeff Hildebrand Lancair ES C-GPSH www.lancaires.com -----Original Message----- From: owner-aeroelectric-list-server@matronics.com [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Troy Scott Subject: AeroElectric-List: annunciator lights --> AeroElectric-List message posted by: "Troy Scott" Gentlemen, Where can I get a good deal on the Honeywell/Microswitch 45/59 series solid-state (LED lit) annunciator lights like the ones Vision MicroSystems used to sell? Lancair Avionics has them, but they want $38 for the annunciator/lens unit. That seems a little steep. I want 10 (maybe 16) of them. Here is a link to what I want: http://content.honeywell.com/sensing/prodinfo/pki/catalog/aml45_59.pdf Also, If any of you have a suggestion for a good substitute, I'd like to hear about it! I already know about the panels from Aircraft Simulators. Regards, Troy Scott tscott1217@bellsouth.net == == == == ________________________________ Message 8 _____________________________________ Time: 07:28:26 AM PST US From: Ken Harrill Subject: RE: AeroElectric-List: Preflight check of SD-8? --> AeroElectric-List message posted by: Ken Harrill --> AeroElectric-List message posted by: Kevin Horton I'm working on the checklists for my RV-8, and am wondering whether there are any potential issues around checking an SD-8 standby alternator right after engine start. I was considering starting the engine, then selecting the SD-8 ON to confirm a voltage rise, then selecting the SD-8 OFF and selecting the main alternator ON. Will the SD-8 have enough output to bring the voltage up even though the battery needs to be recharge? Are there any concerns about load dump issues when I select the SD-8 OFF while it is trying to charge the battery? It seems like the only other opportunity to check the SD-8 preflight would be to select the main alternator OFF during the runup, and check the SD-8 then. But that seems like it could trigger the load dump problems, unless the battery has been charged by then. I'll need the SD-8 as backup when I fly IFR, so I want a way to do a preflight check on it. What is the best way to do this? Kevin, My electrical system is a modified "All Electric on a Budget" system. I check the SD-8 during runup since it does not come on line below about 1500 RPM. My procedure is SD-8 ON, Main Buss OFF then check voltage . If the SD-8 is on line the voltage will be about 14 volts, if not it will be about 12 volts or slightly less. At this point the load meter on my main alternator will go to "0". Then Main Buss ON and SD-8 Off. In 300 hours it has never failed during runup. It will not come on line at idle. I have be thinking about temporarily installing a temperature probe on my SD-8 regulator and going flying to get some empirical data on regulator/heat issue. Ken Harrill RV-6, 300 hours Columbia, SC ________________________________ Message 9 _____________________________________ Time: 07:39:34 AM PST US From: "flyv35b" Subject: Re: AeroElectric-List: annunciator lights --> AeroElectric-List message posted by: "flyv35b" > The cost is insane, but other than these AML series, it's hard to find a > real pro looking annunciator. Electronics International (Bend, OR) has a nice looking LED annunciator light with a attractive chrome bezel, designed to be installed from the front of the panel with a nut on the backside. Cliff A&P/IA ----- Original Message ----- From: "Jeff Hildebrand" Subject: RE: AeroElectric-List: annunciator lights > --> AeroElectric-List message posted by: "Jeff Hildebrand" > > I don't think you can get much of a deal on these lights; we bought ours > from a dealer in Canada for about $32 each. It generally doesn't make > much sense for the shipping, but if you are buying 10 or 16 of them, you > could save some money. > > The cost is insane, but other than these AML series, it's hard to find a > real pro looking annunciator. > > Jeff Hildebrand > Lancair ES C-GPSH > www.lancaires.com > > > -----Original Message----- > From: owner-aeroelectric-list-server@matronics.com > [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Troy > Scott > To: aeroelectric-list@matronics.com > Subject: AeroElectric-List: annunciator lights > > --> AeroElectric-List message posted by: "Troy Scott" > > > Gentlemen, > > Where can I get a good deal on the Honeywell/Microswitch 45/59 series > solid-state (LED lit) annunciator lights like the ones Vision > MicroSystems > used to sell? Lancair Avionics has them, but they want $38 for the > annunciator/lens unit. That seems a little steep. I want 10 (maybe 16) > of > them. Here is a link to what I want: > http://content.honeywell.com/sensing/prodinfo/pki/catalog/aml45_59.pdf > > Also, If any of you have a suggestion for a good substitute, I'd like to > hear about it! I already know about the panels from Aircraft > Simulators. > > Regards, > Troy Scott > tscott1217@bellsouth.net > > > == > == > == > == > > ________________________________ Message 10 ____________________________________ Time: 07:41:17 AM PST US From: DWENSING@aol.com Subject: Re: AeroElectric-List: Coax related --> AeroElectric-List message posted by: DWENSING@aol.com In a message dated 3/17/04 8:43:45 AM Eastern Standard Time, bob.nuckolls@cox.net writes: > > RG-400 (stranded center conductor) or RG-142 (solid) would be an > excellent > substitute for RG-58 (WWII vintage stuff). These modern coaxes will > present 20 db/hundred feet at DME frequencies so 10 feet will > be 2.0 dB and 7.5 feet would be 1.5 dB. RG-58 would be about 26 dB > per hundred so you couldn't make the 1.5 dB requirement in 6' of > coax. > > Bob . . . > > Bob, Related subject......How much loss will be experienced by putting in a right angle BNC adapter at the antenna? I have RG-400 coax. Would you discourage the use of the adapter? Dale Ensing ________________________________ Message 11 ____________________________________ Time: 07:51:28 AM PST US Subject: Re: AeroElectric-List: Preflight check of SD-8? From: "Matt Prather" --> AeroElectric-List message posted by: "Matt Prather" Hi Kevin, Good question. Comments below... > --> AeroElectric-List message posted by: Kevin Horton > > > I'm working on the checklists for my RV-8, and am wondering whether > there are any potential issues around checking an SD-8 standby > alternator right after engine start. I was considering starting the > engine, then selecting the SD-8 ON to confirm a voltage rise, then > selecting the SD-8 OFF and selecting the main alternator ON. > I think checking the SD-8 at start up will work just fine > Will the SD-8 have enough output to bring the voltage up even though > the battery needs to be recharged? Once the starter load is removed from the battery, it won't take much current capacity to recover the battery voltage. Turning the SD-8 will definitely bring the battery voltage above the required charging value. Are there any concerns about load > dump issues when I select the SD-8 OFF while it is trying to charge the I don't think any of the PM alternators are cause for concern with regard to battery dump. Partly because they don't have enough snort to worry about it, and partly because the regulators don't use field current to control output. > battery? It seems like the only other opportunity to check the SD-8 > preflight would be to select the main alternator OFF during the runup, > and check the SD-8 then. But that seems like it could trigger the load > dump problems, unless the battery has been charged by then. > I agree. I don't think this is as good on option as the first one you came up with, which I think poses zero risk to the system. > I'll need the SD-8 as backup when I fly IFR, so I want a way to do a > preflight check on it. What is the best way to do this? I think you already have it. > -- > Kevin Horton RV-8 (finishing kit) > Ottawa, Canada > http://go.phpwebhosting.com/~khorton/rv8/ > Regards, Matt- N34RD ________________________________ Message 12 ____________________________________ Time: 08:07:24 AM PST US From: Speedy11@aol.com Subject: AeroElectric-List: Prop Stopped Best Glide --> AeroElectric-List message posted by: Speedy11@aol.com Joel, One of the aviation magazines, Flying, I think, had an article about 8 years ago on the glide ratio with the prop spinning or stopped - the author did the actual test flying - and the conclusion was that stopping the prop significantly reduced aerodynamic drag and extended the glide. The author's opinion was that it was worthwhile to slow enough to stop the prop and then resume best glide speed. Stan Sutterfield RV-8A Tampa In a message dated 3/17/04 2:56:59 AM Eastern Standard Time, aeroelectric-list-digest@matronics.com writes: << Out of curiosity, has anyone compared the same speed sink rate, with the prop stopped or windmilling? Joel Harding >> ________________________________ Message 13 ____________________________________ Time: 08:41:43 AM PST US From: "LarryRobertHelming" Subject: Re: AeroElectric-List: annunciator lights --> AeroElectric-List message posted by: "LarryRobertHelming" Radio Shack has them also in various colors. Mount from the front with nut on the back. Comes with resistor built in. Nice price too. I've got three of them in my panel. Indiana Larry, RV7 TipUp TMX-O-360 ACS2002 Dynon CNS430 Digitrak JeffRose Flightline Interiors Firewall Forward, Wiring ----- Original Message ----- From: "flyv35b" Subject: Re: AeroElectric-List: annunciator lights > --> AeroElectric-List message posted by: "flyv35b" > > > The cost is insane, but other than these AML series, it's hard to find a > > real pro looking annunciator. > > Electronics International (Bend, OR) has a nice looking LED annunciator > light with a attractive chrome bezel, designed to be installed from the > front of the panel with a nut on the backside. > > Cliff A&P/IA > ----- Original Message ----- > From: "Jeff Hildebrand" > To: > Subject: RE: AeroElectric-List: annunciator lights > > > > --> AeroElectric-List message posted by: "Jeff Hildebrand" > > > > > I don't think you can get much of a deal on these lights; we bought ours > > from a dealer in Canada for about $32 each. It generally doesn't make > > much sense for the shipping, but if you are buying 10 or 16 of them, you > > could save some money. > > > > The cost is insane, but other than these AML series, it's hard to find a > > real pro looking annunciator. > > > > Jeff Hildebrand > > Lancair ES C-GPSH > > www.lancaires.com > > > > > > -----Original Message----- > > From: owner-aeroelectric-list-server@matronics.com > > [mailto:owner-aeroelectric-list-server@matronics.com] On Behalf Of Troy > > Scott > > To: aeroelectric-list@matronics.com > > Subject: AeroElectric-List: annunciator lights > > > > --> AeroElectric-List message posted by: "Troy Scott" > > > > > > Gentlemen, > > > > Where can I get a good deal on the Honeywell/Microswitch 45/59 series > > solid-state (LED lit) annunciator lights like the ones Vision > > MicroSystems > > used to sell? Lancair Avionics has them, but they want $38 for the > > annunciator/lens unit. That seems a little steep. I want 10 (maybe 16) > > of > > them. Here is a link to what I want: > > http://content.honeywell.com/sensing/prodinfo/pki/catalog/aml45_59.pdf > > > > Also, If any of you have a suggestion for a good substitute, I'd like to > > hear about it! I already know about the panels from Aircraft > > Simulators. > > > > Regards, > > Troy Scott > > tscott1217@bellsouth.net > > > > > > == > > == > > == > > == > > > > > > ________________________________ Message 14 ____________________________________ Time: 09:23:47 AM PST US Subject: Re: AeroElectric-List: Prop Stopped Best Glide From: "Matt Prather" --> AeroElectric-List message posted by: "Matt Prather" I have seen other articles that say this is true, but with some caviats... One is that if the engine quits when close to the ground, say on departure, the extended glide afforded by stopping the prop is not likely to be very helpful compared to making sure that you have appropriate airspeed at touchdown. Except for preparing the airplane for the impending landing, NOTHING should distract you from flying the airplane to the landing site. If you burn up all of your airspeed getting the prop to stop, the increased associated sink rate may make it impossible to get the airplane to flair effectively. So, say you're buzzing along at 5000' AGL, and the engine quits, I might mess with trying to stop the prop once I had gone through the restart measures. If I am at 500' AGL, and low airspeed (climb out, pick a spot and fly to it. I'll make sure the fuel and master are turned off, and that the canopy is unlatched. That will burn up much of the altitude right there. Back to work. Matt- N34RD > --> AeroElectric-List message posted by: Speedy11@aol.com > > Joel, > One of the aviation magazines, Flying, I think, had an article about 8 > years ago on the glide ratio with the prop spinning or stopped - the > author did the actual test flying - and the conclusion was that > stopping the prop significantly reduced aerodynamic drag and extended > the glide. The author's opinion was that it was worthwhile to slow > enough to stop the prop and then resume best glide speed. > Stan Sutterfield > RV-8A > Tampa > > In a message dated 3/17/04 2:56:59 AM Eastern Standard Time, > aeroelectric-list-digest@matronics.com writes: > > << Out of curiosity, has anyone compared the same speed sink rate, with > > the prop stopped or windmilling? > > Joel Harding >> > ________________________________ Message 15 ____________________________________ Time: 09:27:57 AM PST US Subject: RE: AeroElectric-List: Preflight check of SD-8? From: "Matt Prather" --> AeroElectric-List message posted by: "Matt Prather" A good point about needing more RPM to get the SD-8 to put out useful power. Ken, do you get zero output below 1500RPM, or just less than the total regulated output? The reason I ask is that I think the B&C 200G on my Continental starts raising bus voltage by about 1000RPM. Matt- N34RD > > Kevin, > > My electrical system is a modified "All Electric on a Budget" system. I > check the SD-8 during runup since it does not come on line below about > 1500 RPM. My procedure is SD-8 ON, Main Buss OFF then check voltage > . If the SD-8 is on line the voltage will be about 14 volts, if not it > will be about 12 volts or slightly less. At this point the load meter > on my main alternator will go to "0". Then Main Buss ON and SD-8 Off. > In 300 hours it has never failed during runup. It will not come on line > at idle. > > > I have be thinking about temporarily installing a temperature probe on > my SD-8 regulator and going flying to get some empirical data on > regulator/heat issue. > > Ken Harrill > RV-6, 300 hours > Columbia, SC > > ________________________________ Message 16 ____________________________________ Time: 10:03:57 AM PST US From: Ken Harrill Subject: RE: AeroElectric-List: Preflight check of SD-8? --> AeroElectric-List message posted by: Ken Harrill Matt, As well as I recall, it does not come online at all until around 1500 RPM. I don't remember if it subsequently goes off line if the RPM is lowered. My habit is to check during runup, not at idle. I will check when I get a chance to fly again. Ken Harrill RV-6, 300 hours Columbia, SC --> AeroElectric-List message posted by: "Matt Prather" A good point about needing more RPM to get the SD-8 to put out useful power. Ken, do you get zero output below 1500RPM, or just less than the total regulated output? The reason I ask is that I think the B&C 200G on my Continental starts raising bus voltage by about 1000RPM. Matt- N34RD > > Kevin, > > My electrical system is a modified "All Electric on a Budget" system. I > check the SD-8 during runup since it does not come on line below about > 1500 RPM. My procedure is SD-8 ON, Main Buss OFF then check voltage > . If the SD-8 is on line the voltage will be about 14 volts, if not it > will be about 12 volts or slightly less. At this point the load meter > on my main alternator will go to "0". Then Main Buss ON and SD-8 Off. > In 300 hours it has never failed during runup. It will not come on line > at idle. > > > I have be thinking about temporarily installing a temperature probe on > my SD-8 regulator and going flying to get some empirical data on > regulator/heat issue. > > Ken Harrill > RV-6, 300 hours > Columbia, SC > ________________________________ Message 17 ____________________________________ Time: 11:05:46 AM PST US From: Hebeard2@aol.com Subject: AeroElectric-List: Aeroelectric Digest --> AeroElectric-List message posted by: Hebeard2@aol.com Matt, I continue to receive the Aeroelectric-list Digest in spite of several attempts to unsubscribe, the latest was yesterday March 16, 2004. The return message was that I was not a subscriber to this list. However today, March 17, 2004, I received three more messages from the Aeroelectric-list Digest. How do I stop these unnecessary messages? I guess one way would to unsubscribe to everything and start over. Harley E. Beard ________________________________ Message 18 ____________________________________ Time: 04:55:32 PM PST US From: "Francis, David CMDR" Subject: AeroElectric-List: SEC: UNCLASSIFIED - STOPPING THE PROP IN AN RV --> AeroElectric-List message posted by: "Francis, David CMDR" Folks, Alex Peterson correctly points out that in an RV the prop can stop below 60kts. Not electrical, but this is an important safety issue for RV pilots. In Australia there have been two fatal accidents related to stopped props. One was an RV4, the other an RV6 with tip up canopy, the significance is that both have the rollover bars behind the pilot. Both accidents were nearly identical as follows: a. both had engine failures after takeoff (one caused by an insecure fuel line, cant remember the other). b. both made dead stick approaches to quite reasonable paddocks upwind of the runways. c. late in both approaches, speed bled below 60kts and the prop stopped. In RVs this is aerodynamically significant. d. at the inboard trailing edge of the wings the fuselage starts to curve away from the wing. At high angles of attack airflow separation starts at this point, and flows aft, over the inboard part of the elevators. This reduces elevator authority, with the prop stopped only. Its fine with engine running. e. when flaring both aircraft to land the reduced elevator authority was insufficient to arrest the rate of descent to normal levels. So both aircraft landed heavy enough to crush the undercarriage. f. without undercarriage the aircraft decelerated at an estimated 4G. This is a very survivable deceleration, but g. the longerons at the cockpit buckled outwards, allowing the rear fuselage to move forward and to bend upwards nearly 90 degrees. h. the rear fuselage moving forward relaxes the shoulder harness, allowing both pilots to flail forward and receive injuries to the forehead. i. as the rear fuselage continued forward the rollover bars crushed the pilots head against the instrument panel. So both died from injuries to the front and back of the head. Moral of the story, in an RV forced landing you MUST stay over 60kts to keep the prop going to avoid loss of elevator authority. Sorry for long post, its all as described at recent safety seminars here in Australia. The pictures of the wreckage were depressing. David Francis, VH-ZEE, Canberra, Australia ________________________________ Message 19 ____________________________________ Time: 05:09:19 PM PST US From: CardinalNSB@aol.com Subject: AeroElectric-List: Re: bench checking, what to watch out for --> AeroElectric-List message posted by: CardinalNSB@aol.com Well, in large part due to reading Bob's book and this list, I have decided to do some of my own avionics install of an audio panel/intercom with marker beacon (pse 7000), gps/com (300xl), kns-80, and probably an ICOM 200. I want to get everything "hooked up" and powered up on the work bench, test the intercom, do a basic "does it power up test" etc. before bolting everything in the airplane. I assume I can use a 12 volt car battery for power with appropriate breaker or fuse. I understand I need to have an antenna on each comm output or I will blow something. Do I need the other antennas hooked up for a basic power on test, such as the dme, marker beacon, or nav? Is there anything else I need to have hooked into the system so I don't damage any of the equipment? Thank you for your help. Skip Simpson ________________________________ Message 20 ____________________________________ Time: 05:13:25 PM PST US From: PeterHunt1@aol.com Subject: AeroElectric-List: Control Stick Switch Overrides --> AeroElectric-List message posted by: PeterHunt1@aol.com Hi bob: Since I didn't get an answer, I hope you don't mind me asking again. I have arranged my copilot stick grip switch overrides as in the lower half of your schematic ... except I left the diodes out. I haven't powered things up yet and so I have two questions. 1) Why do you suggest using diodes? 2) What may/will happen in my arrangement without your diodes? Thanks. Pete Hunt Clearwater, Florida RV-6, installing engine ________________________________ Message 21 ____________________________________ Time: 05:32:15 PM PST US From: "Ed Anderson" Subject: Re: AeroElectric-List: SEC: UNCLASSIFIED - STOPPING THE PROP IN AN RV --> AeroElectric-List message posted by: "Ed Anderson" ----- Original Message ----- From: "Francis, David CMDR" Subject: AeroElectric-List: SEC: UNCLASSIFIED - STOPPING THE PROP IN AN RV > --> AeroElectric-List message posted by: "Francis, David CMDR" > > Folks, > Alex Peterson correctly points out that in an RV the prop can stop below > 60kts. > > Not electrical, but this is an important safety issue for RV pilots. In > Australia there have been two fatal accidents related to stopped props. One > was an RV4, the other an RV6 with tip up canopy, the significance is that > both have the rollover bars behind the pilot. Both accidents were nearly > identical as follows: > > a. both had engine failures after takeoff (one caused by an insecure fuel > line, cant remember the other). > b. both made dead stick approaches to quite reasonable paddocks upwind of > the runways. > c. late in both approaches, speed bled below 60kts and the prop stopped. In > RVs this is aerodynamically significant. > d. at the inboard trailing edge of the wings the fuselage starts to curve > away from the wing. At high angles of attack airflow separation starts at > this point, and flows aft, over the inboard part of the elevators. This > reduces elevator authority, with the prop stopped only. Its fine with engine > running. > e. when flaring both aircraft to land the reduced elevator authority was > insufficient to arrest the rate of descent to normal levels. So both > aircraft landed heavy enough to crush the undercarriage. > f. without undercarriage the aircraft decelerated at an estimated 4G. This > is a very survivable deceleration, but > g. the longerons at the cockpit buckled outwards, allowing the rear fuselage > to move forward and to bend upwards nearly 90 degrees. > h. the rear fuselage moving forward relaxes the shoulder harness, allowing > both pilots to flail forward and receive injuries to the forehead. > i. as the rear fuselage continued forward the rollover bars crushed the > pilots head against the instrument panel. So both died from injuries to the > front and back of the head. > > Moral of the story, in an RV forced landing you MUST stay over 60kts to keep > the prop going to avoid loss of elevator authority. > > Sorry for long post, its all as described at recent safety seminars here in > Australia. The pictures of the wreckage were depressing. > > David Francis, VH-ZEE, Canberra, Australia > I have made two engine out landings with the prop stopped and have not noticed any lack of elevator control authority. However, I did manage my rate of descent such that it never exceeded 750 fpm and airspeed did not decrease below 87 MPH IAS until over the fence and beginning to flare. I agree that with the engine running and producing thrust you have more elevator control authority, but I don't understand how it makes any difference to the elevator if the prop is not producing thrust as to whether it is stopped or turning. I can certainly see how it can make a difference in your rate of descent is high and if low on airspeed. I can vouch that (even with a running engine) you may have difficulty arresting your rate of descent if you either let the rate of descent get too high and/or air speed too low. Appreciate your summary of the unfortunate accidents, I had never considered the cockpit area forshorting due to compression causing the shoulder harness to fail to keep the head out of the panel. Perhaps flying with a helmet as the military do has some merit even in RVs. Ed Ed Anderson RV-6A N494BW Rotary Powered Matthews, NC ________________________________ Message 22 ____________________________________ Time: 06:14:07 PM PST US From: Robert McCallum Subject: Re: AeroElectric-List: Control Stick Switch Overrides --> AeroElectric-List message posted by: Robert McCallum Hi Pete; I'm a different "Bob" but in response to your question, without the diodes you do not necessarily acquire complete override of the co-pilots' controls. When you turn off the co-pilots' controls you prevent him from operating anything UNTIL you, the pilot, operate one of your switches. Now if the co-pilot pushes his switch for the same function and one for another function all at the same time, ground for his "second" switch feeds back from your ground through the first switch duplicating yours and he is able to operate that second system. The diodes prevent this possibility. Sounds very complicated but look at the schematic and visualize both pilot and copilot "down trim" pushed while co-pilots' controls are supposedly "off." You have now re-established a ground for all of the copilots buttons and so during the time that this situation is valid all of the other copilot buttons will work also. Maybe grasping at remote possibilities, but none the less electrically it's possible. The diodes make it impossible. Bob McC PeterHunt1@aol.com wrote: >--> AeroElectric-List message posted by: PeterHunt1@aol.com > >Hi bob: > >Since I didn't get an answer, I hope you don't mind me asking again. I have >arranged my copilot stick grip switch overrides as in the lower half of your >schematic ... except I left the diodes out. I haven't powered things up yet >and so I have two questions. 1) Why do you suggest using diodes? 2) What >may/will happen in my arrangement without your diodes? Thanks. > >Pete Hunt >Clearwater, Florida >RV-6, installing engine > > > > ________________________________ Message 23 ____________________________________ Time: 06:24:42 PM PST US From: Kevin Horton AN RV Subject: Re: AeroElectric-List: SEC: UNCLASSIFIED - STOPPING THE PROP IN AN RV --> AeroElectric-List message posted by: Kevin Horton AN RV >--> AeroElectric-List message posted by: "Francis, David CMDR" > > >Folks, >Alex Peterson correctly points out that in an RV the prop can stop below >60kts. > >Not electrical, but this is an important safety issue for RV pilots. In >Australia there have been two fatal accidents related to stopped props. One >was an RV4, the other an RV6 with tip up canopy, the significance is that >both have the rollover bars behind the pilot. Both accidents were nearly >identical as follows: > >a. both had engine failures after takeoff (one caused by an insecure fuel >line, cant remember the other). >b. both made dead stick approaches to quite reasonable paddocks upwind of >the runways. >c. late in both approaches, speed bled below 60kts and the prop stopped. In >RVs this is aerodynamically significant. >d. at the inboard trailing edge of the wings the fuselage starts to curve >away from the wing. At high angles of attack airflow separation starts at >this point, and flows aft, over the inboard part of the elevators. This >reduces elevator authority, with the prop stopped only. Its fine with engine >running. >e. when flaring both aircraft to land the reduced elevator authority was >insufficient to arrest the rate of descent to normal levels. So both >aircraft landed heavy enough to crush the undercarriage. >f. without undercarriage the aircraft decelerated at an estimated 4G. This >is a very survivable deceleration, but >g. the longerons at the cockpit buckled outwards, allowing the rear fuselage >to move forward and to bend upwards nearly 90 degrees. >h. the rear fuselage moving forward relaxes the shoulder harness, allowing >both pilots to flail forward and receive injuries to the forehead. >i. as the rear fuselage continued forward the rollover bars crushed the >pilots head against the instrument panel. So both died from injuries to the >front and back of the head. > >Moral of the story, in an RV forced landing you MUST stay over 60kts to keep >the prop going to avoid loss of elevator authority. > >Sorry for long post, its all as described at recent safety seminars here in >Australia. The pictures of the wreckage were depressing. > >David Francis, VH-ZEE, Canberra, Australia Interesting accidents, but I think you have drawn the wrong conclusion. If the prop is windmilling (i.e. the engine has failed, but the air is keeping the prop turning), the drag is much higher than if the prop is stopped. The air actually slows down as it goes through a windmilling prop. So the inboard wing is likely to stall a bit earlier than if the prop was stopped, or if the engine was running. The lower air velocity in the prop wash will also reduce elevator effectiveness. This is the reverse of what happens if the engine is producing power and it is spinning the prop. In that case the air speeds up as it goes through the prop, and this increased air velocity helps keep the inboard wing from stalling, and it increases elevator effectiveness. So, the real problem was that the pilots allowed the speed to get too slow. The fact that the prop stopped actually would have helped them, but it was not enough of a help to make up for the too slow speed. The real lesson to draw from these accidents is to not let the speed bleed off below a normal approach speed. Faster is even better. -- Kevin Horton RV-8 (finishing kit) Ottawa, Canada http://go.phpwebhosting.com/~khorton/rv8/