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ELT location

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trigo(at)mail.telepac.pt
Guest

Posted: Sat Jan 17, 2009 4:29 am Post subject: ELT location

Although this is not a direct Electrical related issue, the RV List is not

so active and there are many RV builders and flyers around this one, so Bob

will forgive me for posting it here.



Van's sells a sub-kit intended for the installation of the AmeriKing ELT on

2-place side-by-side RV's (7 and 9), and its instructions place it in the

tail, right behind the baggage compartment aft bulkhead.



IMHO that is not the best place to install this ELT because its capability

of voice transmission in case one survives a crash is somehow defeated. You

would have to unscrew more than 20 screws to remove that bulkhead corrugated

cover to reach the ELT.

 

Where does the 7 and 9 gang have installed the ELT? 

Inside the baggage compartment, at an easy reach of the pilot?

And how about the ELT's external antenna?



Carlos

nuckolls.bob(at)aeroelect
Guest

Posted: Sat Jan 17, 2009 6:50 am Post subject: ELT location

At 06:27 AM 1/17/2009, you wrote:

 	  Quote: 	
		  

<trigo(at)mail.telepac.pt>



Although this is not a direct Electrical related issue, the RV List is not

so active and there are many RV builders and flyers around this one, so Bob

will forgive me for posting it here.



Van's sells a sub-kit intended for the installation of the AmeriKing ELT on

2-place side-by-side RV's (7 and 9), and its instructions place it in the

tail, right behind the baggage compartment aft bulkhead.



IMHO that is not the best place to install this ELT because its capability

of voice transmission in case one survives a crash is somehow defeated. You

would have to unscrew more than 20 screws to remove that bulkhead corrugated

cover to reach the ELT.



Where does the 7 and 9 gang have installed the ELT?

Inside the baggage compartment, at an easy reach of the pilot?

And how about the ELT's external antenna?


	


     It's an entirely appropriate question . . . to which

     I would offer the following . . .



     The optimized location for ELT installation was

     picked almost 50 years ago as the area of an airplane

     most likely to survive a crash. Rearward in the tailcone

     with the antenna just forward of structure in the

     vertical fin.



     Given that non-gps aided, beacon ELTs are of

     substantive value in only a small percentage of

     rescues, it seem that the "voice transmission" capability

     is of dubious value. If one assumes worst case conditions,

     what ever value the ELT has to offer will be protected

     if the legacy installation protocols are observed.



     After you've wadded your airplane up into a ball,

     the existence of a non-gps aided ELT seems to serve little

     purpose other than to comply with a rule. Anyone

     on board the aircraft is capable of exploiting

     the voice transmission feature would be better off

     using the stuff that should be in everybody's flight

     bag. This equipment is accessible to survivors without

     to disassembly of of the airplane.



http://aeroelectric.com/Pictures/Misc/Vacination_for_Dark_Panel_Syndrom.pdf



     It's interesting to note that the AmeriKing folks

     earned themselves unfavorable noticed by the FCC

     when on several occasions were asked to stop clear

     field emissions to 406 Mhz rescue satellites.



http://www.fcc.gov/eb/Orders/2008/DA-08-402A1.html



     We have no first hand knowledge of how this

     all came about.  It's curious that anyone

     developing new hardware would not be 100.00% sure

     of operational compliance in the screen-room before

     venturing out to do COORDINATED, open air testing

     of any kind. Tweaking the whiskers of the sleeping

     tiger is a risky pastime.

        Bob . . .



        ----------------------------------------)

        ( . . .  a long habit of not thinking   )

        ( a thing wrong, gives it a superficial )

        ( appearance of being right . . .       )

        (                                       )

        (                  -Thomas Paine 1776-  )

        ----------------------------------------

bcollinsmn

Joined: 17 Aug 2008
Posts: 23
Location: St. Paul, MN.

Posted: Sat Jan 17, 2009 7:14 am Post subject: Re: ELT location

We also kicked this around on the RV List in november. I don't have an exact link but I referenced the discussion here:



http://rvbuildershotline.com/archives/2008/20081122.html



The original question I had, however, wasn't so much about the unit, it was about the antenna. Many RVers tuck it around the rollbar, which seemed to preclude a decent ground plane to me (if I understand ground plane correctly).



The general consensus seemed to be, don't worry about it, it's not going to work anyway, which seemed an odd position for people who are so meticulous about the possibility of corrosion rotting  their metal airplanes in record time or any of the other million things with little chance of happening that we obsess over.    



Here's what I ended up doing, by the way. 



http://rvnewsletter.blogspot.com/2008/11/installing-heres-where-my-remains-are.html



I had intended to run the antenna up a bulkhead support as indicated in that latter link and that have the antenna up top just afte of another bulkhead. Since then, i've bought a Dynon D100 and it recommends the remote compass in that same location. So now I'm wondering if the antenna will interfere with the th Dynon magnetometer?

_________________
Bob Collins
St. Paul, Minn.
RV-7A - Running wires
http://rvbuildershotline.com
Day job: http://minnesota.publicradio.org/collections/special/columns/news_cut/

rv9jim(at)juno.com
Guest

Posted: Sat Jan 17, 2009 2:40 pm Post subject: ELT location

Carlos,

        I have a "9" with the slider canopy.  I mounted my "required" ELT

on the frame just behind the pass. seat.  I use a Ameri king  (the redish

colored one) and using the fame as the main mount, I ran the antenna back

through it and mounted it to the top of the cover that encloses the

rudder cable in the baggage compartment.  This lets me remove the whole

unit easily if I need to in the future.   Some day there will be a

reasonable 406 mz unit and I will put it in the tail cone behind the

baggage compartment.  There are lots of problems with antenna placement. 

First, there is a very good chance I will flip over.  This places the

antenna under the airframe.  The rudder will protect the antenna to a

point.  That may break it off.  I placed the antenna inside as my pix

shows.  Not the best but it will work.  The very low power of the

transmitter leaves much to be desired but its there.  I have a PLB that I

carry in my survival vest.  If I can get out or at least put the PLB out

side of the airframe, it has a built in gps so they can find me fairly

quickly.  I hope that gives you some ideas.



Jim Nelson

N15JN

RV9-A

____________________________________________________________

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bicyclop(at)pacbell.net
Guest

Posted: Sat Jan 17, 2009 11:15 pm Post subject: ELT location

trigo(at)mail.telepac.pt
Guest

Posted: Sun Jan 18, 2009 3:00 am Post subject: ELT location

Thank you very much, James.  

That's exactly the kind of answer I needed!!  

   

In a further comment, I am also waiting for decent prices on 406MHz ELT's, but AmeriKing has recently released the AK-451, with and without GPS (It’s funny how they’re already in Aircraft Spruce catalogue but not in AmeriKing website?!).  

Unfortunately, the international (INT) version (I need it for Europe) with GPS seems not yet available, therefore I’ll have to wait a little bit longer.  

   

However, together with 121.5, 243 and 406 MHz frequencies and GPS position transmission, this unit seems to have voice transmission as well, so it looks that, beyond all other location recommendations (structural attachment, directional position, less potential destructive place, etc.), one should install it in an easy reachable position inside the cabin.   

   

Carlos  

   

   

[quote] --

bicyclop(at)pacbell.net
Guest

Posted: Sun Jan 18, 2009 10:39 am Post subject: ELT location

James,



I tried last night but my message came through empty.

The way your ELT is mounted, the 'G' switch is oriented to starboard 

instead of down. I think it would take a pretty unusual crash to 

activate it. Mounted that way, it is unlikely to pass inspection, too. 

You might want to rethink it.



Van's recommends and supplies kits for mounting behind the baggage 

bulkhead to some pretty solid structure. That meets the ELT 

manufacturer's specs and the FAA's as well. I know a guy who mounted his 

to the baggage floor and zip tied the remote switch right too it. His 

passed the DAR's scrutiny, OK.



Pax,



Ed Holyoke



James H Nelson wrote:

 	  Quote: 	
		   Carlos,

         I have a "9" with the slider canopy.  I mounted my "required" ELT

 on the frame just behind the pass. seat.  I use a Ameri king  (the redish

 colored one) and using the fame as the main mount, I ran the antenna back

 through it and mounted it to the top of the cover that encloses the

 rudder cable in the baggage compartment.  This lets me remove the whole

 unit easily if I need to in the future.   Some day there will be a

 reasonable 406 mz unit and I will put it in the tail cone behind the

 baggage compartment.  There are lots of problems with antenna placement. 

 First, there is a very good chance I will flip over.  This places the

 antenna under the airframe.  The rudder will protect the antenna to a

 point.  That may break it off.  I placed the antenna inside as my pix

 shows.  Not the best but it will work.  The very low power of the

 transmitter leaves much to be desired but its there.  I have a PLB that I

 carry in my survival vest.  If I can get out or at least put the PLB out

 side of the airframe, it has a built in gps so they can find me fairly

 quickly.  I hope that gives you some ideas.



 Jim Nelson

 N15JN

 RV9-A

AV8ORJWC

Joined: 13 Jul 2006
Posts: 1149
Location: Aurora, Oregon "Home of VANS"

Posted: Sun Jan 18, 2009 3:27 pm Post subject: ELT location

There is an old Van builder's Tale of the instructions for installation of an "effective" ELT and rigging of the antennae with proper ground plane.  If it annunciates at all, from a few feet away, then it must be compliant.  We check the battery life, confirm it annunciates from a few feet and they fly for another year.

  

 Most builders install the device to comply with a requirement in a written document that one must be onboard.  Most ELTs do not emit a proper signal and few builders care to research why.

  

 I dropped by ARTEX last week to query them on my understanding of RF transmission signals (in the 121 to  406 range) and they confirmed that most ELTs are installed for looks, not for their intended function of timely location.  Maybe that is why the location of downed aircraft receive the response they do. It could be the non-activation of the switch, it could be that cute, hidden antenna.

  

 Ground planes below the skin of the aircraft are one false tale, Installation of an antenna next to a rigid structure is another.  Lets all agree we are doing the installation for compliance, not function and that aethetics plays a big role in not doing it correctly.  I acknowledge that sliders affect the logic of sound antenna placement.  My understanding is that the RF signals don't care one whit about any of that.

  

 Now getting into Canada next month, now that is a meaningful question.

  



  John Cox

 do not archive



 

  From: owner-aeroelectric-list-server(at)matronics.com on behalf of bcollinsmn

Sent: Sat 1/17/2009 7:14 AM

To: aeroelectric-list(at)matronics.com

Subject: Re: ELT location

  

--> AeroElectric-List message posted by: "bcollinsmn" <bob(at)rvbuildershotline.com>



We also kicked this around on the RV List in november. I don't have an exact link but I referenced the discussion here:



http://rvbuildershotline.com/archives/2008/20081122.html



The original question I had, however, wasn't so much about the unit, it was about the antenna. Many RVers tuck it around the rollbar, which seemed to preclude a decent ground plane to me (if I understand ground plane correctly).



The general consensus seemed to be, don't worry about it, it's not going to work anyway, which seemed an odd position for people who are so meticulous about the possibility of corrosion rotting  their metal airplanes in record time or any of the other million things with little chance of happening that we obsess over.  [Laughing] 



Here's what I ended up doing, by the way.



http://rvnewsletter.blogspot.com/2008/11/installing-heres-where-my-remains-are.html



I had intended to run the antenna up a bulkhead support as indicated in that latter link and that have the antenna up top just afte of another bulkhead. Since then, i've bought a Dynon D100 and it recommends the remote compass in that same location. So now I'm wondering if the antenna will interfere with the th Dynon magnetometer?



--------

Bob Collins

St. Paul, Minn.

RV-7A (#&amp;^ fiberglass!)

http://rvbuildershotline.com

Day job:  http://minnesota.publicradio.org/collections/special/columns/news_cut/





Read this topic online here:



http://forums.matronics.com/viewtopic.php?p=225286#225286

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 [quote][b]

rv9jim(at)juno.com
Guest

Posted: Thu Jan 22, 2009 4:25 pm Post subject: ELT location

Hi Ed,

        Shoot, I'll have to look at it.  My last bird mounted it the same

way (switches forward) but it was a different mfg.  I assumed (bad me)

that the orientation would be the same. I don't have a lot of reason to

believe that this unit will be of any help.  Its there for the DAR and

regulations.  That is why I bought a PLB with GPS.  If I'm alive, I will

remove it from my survival vest and turn it on.  Even if I'm upside down,

I will break the canopy and stick my arm outside and run it.  As a note,

I have a survival vest that I got from the U.S. Army during my 32 years

with them flying helicopters.  It has a good survival knife, pocket for a

survival radio (my PLB) and lots of other neat stuff to keep you alive

for a while.  A good fishing vest with pockets all over will do the same

thing. I should weigh it to see what it weighs as I think it is around 7#

 =/-   a pound or two.  

Thanks again for the heads up.



Jim

____________________________________________________________

Click for free info on college degrees.

http://thirdpartyoffers.juno.com/TGL2141/fc/PnY6rw1U6R6KubryOwbqqIvdia8uuNezTxsmslPHQHES9IEeUMJwV/

bicyclop(at)pacbell.net
Guest

Posted: Thu Jan 22, 2009 7:21 pm Post subject: ELT location

Howdy Jim,



Yeah, the switches should be forward, but there is a side (the wide one) 

which is supposed to face down. You're right, it probably won't save 

your life no matter how you mount it, but you do have to get it signed 

off.  Good luck with it.



Pax,



Ed



James H Nelson wrote:

 	  Quote: 	
		   



 Hi Ed,

         Shoot, I'll have to look at it.  My last bird mounted it the same

 way (switches forward) but it was a different mfg.  I assumed (bad me)

 that the orientation would be the same. I don't have a lot of reason to

 believe that this unit will be of any help.  Its there for the DAR and

 regulations.  That is why I bought a PLB with GPS.  If I'm alive, I will

 remove it from my survival vest and turn it on.  Even if I'm upside down,

 I will break the canopy and stick my arm outside and run it.  As a note,

 I have a survival vest that I got from the U.S. Army during my 32 years

 with them flying helicopters.  It has a good survival knife, pocket for a

 survival radio (my PLB) and lots of other neat stuff to keep you alive

 for a while.  A good fishing vest with pockets all over will do the same

 thing. I should weigh it to see what it weighs as I think it is around 7#

  =/-   a pound or two.  

 Thanks again for the heads up.



 Jim

 ____________________________________________________________

 Click for free info on college degrees.

 http://thirdpartyoffers.juno.com/TGL2141/fc/PnY6rw1U6R6KubryOwbqqIvdia8uuNezTxsmslPHQHES9IEeUMJwV/

rv9jim(at)juno.com
Guest

Posted: Fri Jan 23, 2009 6:03 am Post subject: ELT location

Hi Ed,

        Signed off and flying !!!!

Jim

____________________________________________________________

Come clean with a brand new shower. Click now!

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bicyclop(at)pacbell.net
Guest

Posted: Fri Jan 23, 2009 8:50 am Post subject: ELT location

Cool!



Ed



James H Nelson wrote:

 	  Quote: 	
		   



 Hi Ed,

         Signed off and flying !!!!

 Jim

 ____________________________________________________________

 Come clean with a brand new shower. Click now!

 http://thirdpartyoffers.juno.com/TGL2141/fc/PnY6rw1wsgyplM6sWzTdAzPIKtAeZbj06hKJGMTU7MVQ2WL6FeifP/

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