---------------------------------------------------------- Avionics-List Digest Archive --- Total Messages Posted Fri 02/10/06: 5 ---------------------------------------------------------- Today's Message Index: ---------------------- 1. 07:30 AM - antennas () 2. 07:42 AM - A Better PLB Web Site () 3. 09:04 AM - Re: antennas (Rueb, Duane) 4. 07:01 PM - Re: A Better PLB Web Site (W J R HAMILTON) 5. 07:01 PM - Re: antennas (W J R HAMILTON) ________________________________ Message 1 _____________________________________ Time: 07:30:13 AM PST US From: Cc: , Subject: Avionics-List: antennas --> Avionics-List message posted by: Responding to an AeroElectric-List message previously posted by: "bob noffs" 2/10/2006 Hello Bob, Dare I post some heresy? Will the gummint sic its watch dogs on me? Will the electromagnetic radiation purists on the list rise up in total fury to slap me down? Well, I'll take a chance. Suppose that the gummint, in its infinite wisdom, mandated that every aircraft carry 3 pounds of butter and a container of maple syrup just in case the survival situation after crashing resulted in a supply of pancakes as the available food supply. Would you insist on carrying genuine maple syrup or would an imitation be good enough for you? Maybe an ELT is a little more useful than butter and maple syrup in a crash situation, but I sure as hell wouldn't place my entire faith in being found and rescued in one of the garden variety ELT's that we are mandated to carry. My point is that obsessing over antenna ground plane details is wasted time. Nobody knows exactly what attitude their aircraft will be in when it finishes crashing. The ELT antenna could end up pointing directly down at, and a few inches from, the surface of the earth. How much difference would a perfect ground plane, if one could construct one, make in that situation? Here is my thinking: 1) To be legal, buy one of the garden variety ELT's that we are mandated to carry. Install it securely in the proper location in the proper attitude with regard to its deceleration sensor. Fasten on the wire antenna that came with the ELT and don't obsess over ground planes or what the antenna's attitude will be when you finish crashing. Go fly. 2) If you want to take some truly effective steps for rescue after crashing you can, and probably should to the degree that you are concerned and considering routes of flight, do some or all of the following. 2A) Always carry a hand held VHF comm radio with a battery supply that you KNOW to be capable of extended operation. 2B) Always carry a cell phone with a battery supply that you KNOW to be capable of extended operation. 2C) Purchase and carry a PLB http://www.equipped.com/faq_plb/default.asp 2D) Carry a tough plastic container of water -- size your choice. My experience with even short time rescued people is that they experienced an almost mentally debilitating thirst shortly after crashing. 2E) Carry a knife of enough size and sturdiness to punch through / crack your plastic windows and canopy. I am sure that other posters will add their favorite / essential crash survival items, but obsessing over these items falls into the same category of time wasting like obsessing over ground planes. Take what you deem to be reasonable precautions to be rescued after a survivable crash and then proceed to fly worry and guilt free (and legal). OC PS: If you have the bank account to afford one of the new 406 Mhz ELT's, go for it. << hi all, I have several antennas to install. My elt requires a ground plane. Tim at b and c was very helpful with my questions but i question leads to 5 more. Is there any way around a ground plane for the elt? If not, any suggestions on how to make it in my wood/cloth fuselage? At first i thought numerous strips of thin copper way the way to go but that looks like just more fasteners. Can a very thin sheet be laid down in the fuse. bottom? It wouldnt exactly be flat with all the woodworking to go around.....skip.....Thanks in advance, bob noffs>> ________________________________ Message 2 _____________________________________ Time: 07:42:57 AM PST US From: Subject: Avionics-List: A Better PLB Web Site --> Avionics-List message posted by: 2/10/2006 I wish that I had included this web site in my response to Bob Noffs' question about making a ground plane for an ELT antenna. http://www.sarsat.noaa.gov/emerbcns.html Here is an extract from that site regarding our currently government mandated ELT's: "Unfortunately, these have proven to be highly ineffective. They have a 97% false alarm rate, activate properly in only 12% of crashes, and provide no identification data." OC ________________________________ Message 3 _____________________________________ Time: 09:04:59 AM PST US Subject: RE: Avionics-List: antennas From: "Rueb, Duane" --> Avionics-List message posted by: "Rueb, Duane" OC. Well, now on the topic of the Maple syrup that we should carry, even though my own preference would be for the genuine stuff, the imitation would be more practical due to storage considerations, now, of course, we know that refrigeration is required for the genuine after opening, and is even a good idea with the fake stuff, but who can guarantee that some hungry passenger, or pilot, would not have violated the seal and had a taste before we had our emergency event. Wow, these things do get complicated. Good we have the Gummint working on this for us. On a serious vein, what is the advantage of the 406 Mhz ones, is it just the smaller dimensions needed for antenna and ground plane? Or is there some other factor involved? Duane Rueb, KF6GYB & PG-12-32627, also Kitfox N24ZM -----Original Message----- From: owner-avionics-list-server@matronics.com [mailto:owner-avionics-list-server@matronics.com] On Behalf Of bakerocb@cox.net Sent: Friday, February 10, 2006 7:27 AM Cc: avionics-list@matronics.com; aeroelectric-list@matronics.com Subject: Avionics-List: antennas --> Avionics-List message posted by: Responding to an AeroElectric-List message previously posted by: "bob noffs" 2/10/2006 Hello Bob, Dare I post some heresy? Will the gummint sic its watch dogs on me? Will the electromagnetic radiation purists on the list rise up in total fury to slap me down? Well, I'll take a chance. Suppose that the gummint, in its infinite wisdom, mandated that every aircraft carry 3 pounds of butter and a container of maple syrup just in case the survival situation after crashing resulted in a supply of pancakes as the available food supply. Would you insist on carrying genuine maple syrup or would an imitation be good enough for you? Maybe an ELT is a little more useful than butter and maple syrup in a crash situation, but I sure as hell wouldn't place my entire faith in being found and rescued in one of the garden variety ELT's that we are mandated to carry. My point is that obsessing over antenna ground plane details is wasted time. Nobody knows exactly what attitude their aircraft will be in when it finishes crashing. The ELT antenna could end up pointing directly down at, and a few inches from, the surface of the earth. How much difference would a perfect ground plane, if one could construct one, make in that situation? Here is my thinking: 1) To be legal, buy one of the garden variety ELT's that we are mandated to carry. Install it securely in the proper location in the proper attitude with regard to its deceleration sensor. Fasten on the wire antenna that came with the ELT and don't obsess over ground planes or what the antenna's attitude will be when you finish crashing. Go fly. 2) If you want to take some truly effective steps for rescue after crashing you can, and probably should to the degree that you are concerned and considering routes of flight, do some or all of the following. 2A) Always carry a hand held VHF comm radio with a battery supply that you KNOW to be capable of extended operation. 2B) Always carry a cell phone with a battery supply that you KNOW to be capable of extended operation. 2C) Purchase and carry a PLB http://www.equipped.com/faq_plb/default.asp 2D) Carry a tough plastic container of water -- size your choice. My experience with even short time rescued people is that they experienced an almost mentally debilitating thirst shortly after crashing. 2E) Carry a knife of enough size and sturdiness to punch through / crack your plastic windows and canopy. I am sure that other posters will add their favorite / essential crash survival items, but obsessing over these items falls into the same category of time wasting like obsessing over ground planes. Take what you deem to be reasonable precautions to be rescued after a survivable crash and then proceed to fly worry and guilt free (and legal). OC PS: If you have the bank account to afford one of the new 406 Mhz ELT's, go for it. << hi all, I have several antennas to install. My elt requires a ground plane. Tim at b and c was very helpful with my questions but i question leads to 5 more. Is there any way around a ground plane for the elt? If not, any suggestions on how to make it in my wood/cloth fuselage? At first i thought numerous strips of thin copper way the way to go but that looks like just more fasteners. Can a very thin sheet be laid down in the fuse. bottom? It wouldnt exactly be flat with all the woodworking to go around.....skip.....Thanks in advance, bob noffs>> ________________________________ Message 4 _____________________________________ Time: 07:01:07 PM PST US From: W J R HAMILTON Subject: Re: Avionics-List: A Better PLB Web Site Cc: , --> Avionics-List message posted by: W J R HAMILTON Folks, See my previous post, I rest my case. Cheers, Bill Hamilton At 21:42 10/02/2006, bakerocb@cox.net wrote: >--> Avionics-List message posted by: > >2/10/2006 > >I wish that I had included this web site in my response to Bob Noffs' >question about making a ground plane for an ELT antenna. > >http://www.sarsat.noaa.gov/emerbcns.html > >Here is an extract from that site regarding our currently government >mandated ELT's: > >"Unfortunately, these have proven to be highly ineffective. They have a 97% >false alarm rate, activate properly in only 12% of crashes, and provide no >identification data." > >OC > > CONFIDENTIALITY & PRIVILEGE NOTICE W.J.R.Hamilton,Glenalmond Group Companies,Fighter Flights Internet Services and Warbirds.Net. & . This message is intended for and should only be used by the addressee. It is confidential and may contain legally privileged information.If you are not the intended recipient any use distribution,disclosure or copying of this message is strictly prohibited.Confidentiality and legal privilege attached to this communication are not waived or lost by reason of the mistaken delivery to you.If you have received this message in error, please notify us immediately to: Australia 61 (0)408 876 526 Dolores capitis non fero. Eos do. ________________________________ Message 5 _____________________________________ Time: 07:01:07 PM PST US From: W J R HAMILTON Subject: Re: Avionics-List: antennas --> Avionics-List message posted by: W J R HAMILTON Folks, In Australia, legislation to mandate fixed ELT in all GA aircraft was defeated in the Parliament, after a lobbying campaign by AOPA Australia. We do have legislation for the mandatory carriage of handheld ELT/EPIRB ( your PLB) on all flights over 50 miles from base. The statistics are stark, in actual crash scenarios, the failure rate of fixed ELT is around 95%. The most common cause of failure is the disruption of the antenna or the aerial cable from the box to the antenna, for all the reasons you can think of. Another common reason is that the aircraft is in the water , 100% of ELT's do not work under water. Post accident fire, prior internal failure etc, are common additional causes. In contrast, in survivable accidents, 100% of hand held ELT have worked. In non-survivable accidents, all you are talking about is saving search costs. Given what little information is available in the US ( I did a lot of work jointly with the Civil Air Patrol on the subject) the 95% + failure rate holds good in the US ---- As you might expect, given the causes of failure are inherent in the design/installation of fixed ELT. Remember that the US legislation to mandate ELT bypassed all the usual consultation, cost benefit analysis etc, it was a knee jerk political reaction to the loss of an aircraft in Alaska, I don't recall if it was a Congressman or Senator that was lost. There is absolutely NO evidence to show that the outcome of that accident would have been any different had the aircraft been fitted with an ELT, statistically there was a better than 95% failure probability. Given actual accident, the failure probability was closer to 100%. In view of phasing out the COSPAR/SARSAT on 121.5/243, in accord with the latest specifications for new generation ELT, commodity priced 400 mcs GPS/ELT are now available. Interestingly, because of the low cost of an ELT, their use is widespread, even Forest Service type organisations ( the name varies state by state) rent ELT to hikers who do not have their own, most 4 Wheel Drivers carry one now, if they are in a remote area. In short, fixed ELT are a total waste on money. Even in three airline accidents ( all Airbus) that we could track down, where the tail mounted ELT survived in-tact in a largely intact tail section, all three ELT failed to transmit a useable signal. Cheers, Bill Hamilton. At 21:28 10/02/2006, you wrote: >--> Avionics-List message posted by: > >Responding to an AeroElectric-List message previously posted by: "bob noffs" > > >2/10/2006 > >Hello Bob, Dare I post some heresy? Will the gummint sic its watch dogs on >me? Will the electromagnetic radiation purists on the list rise up in total >fury to slap me down? Well, I'll take a chance. > >Suppose that the gummint, in its infinite wisdom, mandated that every >aircraft carry 3 pounds of butter and a container of maple syrup just in >case the survival situation after crashing resulted in a supply of pancakes >as the available food supply. Would you insist on carrying genuine maple >syrup or would an imitation be good enough for you? > >Maybe an ELT is a little more useful than butter and maple syrup in a crash >situation, but I sure as hell wouldn't place my entire faith in being found >and rescued in one of the garden variety ELT's that we are mandated to >carry. My point is that obsessing over antenna ground plane details is >wasted time. > >Nobody knows exactly what attitude their aircraft will be in when it >finishes crashing. The ELT antenna could end up pointing directly down at, >and a few inches from, the surface of the earth. How much difference would a >perfect ground plane, if one could construct one, make in that situation? > >Here is my thinking: > >1) To be legal, buy one of the garden variety ELT's that we are mandated to >carry. Install it securely in the proper location in the proper attitude >with regard to its deceleration sensor. Fasten on the wire antenna that came >with the ELT and don't obsess over ground planes or what the antenna's >attitude will be when you finish crashing. Go fly. > >2) If you want to take some truly effective steps for rescue after crashing >you can, and probably should to the degree that you are concerned and >considering routes of flight, do some or all of the following. > >2A) Always carry a hand held VHF comm radio with a battery supply that you >KNOW to be capable of extended operation. > >2B) Always carry a cell phone with a battery supply that you KNOW to be >capable of extended operation. > >2C) Purchase and carry a PLB http://www.equipped.com/faq_plb/default.asp > >2D) Carry a tough plastic container of water -- size your choice. My >experience with even short time rescued people is that they experienced an >almost mentally debilitating thirst shortly after crashing. > >2E) Carry a knife of enough size and sturdiness to punch through / crack >your plastic windows and canopy. > >I am sure that other posters will add their favorite / essential crash >survival items, but obsessing over these items falls into the same category >of time wasting like obsessing over ground planes. Take what you deem to be >reasonable precautions to be rescued after a survivable crash and then >proceed to fly worry and guilt free (and legal). > >OC > >PS: If you have the bank account to afford one of the new 406 Mhz ELT's, go >for it. > ><< hi all, I have several antennas to install. My elt requires a ground >plane. Tim at b and >c was very helpful with my questions but i question leads to 5 more. Is >there >any way around a ground plane for the elt? If not, any suggestions on how to >make it in my wood/cloth fuselage? At first i thought numerous strips of >thin >copper way the way to go but that looks like just more fasteners. Can a very >thin sheet be laid down in the fuse. bottom? It wouldnt exactly be flat with >all the woodworking to go around.....skip.....Thanks in advance, bob noffs>> > > CONFIDENTIALITY & PRIVILEGE NOTICE W.J.R.Hamilton,Glenalmond Group Companies,Fighter Flights Internet Services and Warbirds.Net. & . This message is intended for and should only be used by the addressee. It is confidential and may contain legally privileged information.If you are not the intended recipient any use distribution,disclosure or copying of this message is strictly prohibited.Confidentiality and legal privilege attached to this communication are not waived or lost by reason of the mistaken delivery to you.If you have received this message in error, please notify us immediately to: Australia 61 (0)408 876 526 Dolores capitis non fero. Eos do.