EFWD Build

[efwd]

Perfect Dave, thank you for the advice. I knew I was going to get input on the unprotected clamps but I was hustling to go to work as I just finished locating the antenna where it is. I was not sure what I was going to use under the clamps so it was helpful to get that info. Thanks again.
Eddie

[Cherrybark]

It is so very useful to have Eddie posting solutions to problems as I trail along a few months behind! Now my ELT mounting question is resolved.

[jrevens]

Eddie,

Yes, as Dave said, you definitely need to "ground" your "ground plane"... it's an important part of the antenna "system".

As far as wooden aircraft (or composite aircraft for that matter) are concerned, a metal ground plane is fabricated and attached to the structure and is then grounded via a wire to the ground system of the airplane.

[jiott]

You might give some thought to mounting your ELT in a more easily accessible spot. It looks to me like your going to have to remove the baggage floor (not real easy to do) to get at the ELT. Remember it has to be completely removed in order to properly test it at EACH annual. Those annuals seem to come around very quickly. Also in case your remote switch wire is damaged in a crash, you want to be able to reach the manual ON switch on the ELT if you are still alive.

I am doing an annual now, and I find I don't need to remove the baggage floor to get at everything. I just undo all the velcro holding the sides up and fold them down onto the floor. This nicely exposes my ELT which is mounted on the outside of the baggage compartment.

[efwd]

Thank You John, very helpful.
Jim, Thanks for the pointers. I had thought of the points you mention with one exception. I sure as heck won't be able to reach the switch on the device itself in the event the panel switch is damaged. As for the location under the baggage floor. I have used nut plates on four of the six attach points to make removing the floor pretty simple actually. I just unscrew the hardware from the inside. The two immediately behind the seat pan are accessible with a wrench when the seat pan is removed. I did that anticipating my need to remove the bag to clean it. I hate dirty interiors. However, to get the ELT out it is actually pretty accessible once the seat pan is removed. Certainly, in an annual, I will be needing to remove the pan to inspect underneath. I can reach in behind the header tank, flip the latch on the retaining strap and it comes right out through the space just beside the header tank.
I considered several other locations but my ELT has to be mounted on ridged structure on a horizontal plane with the face of the device facing forward. The installation guide puts a limit on the amount of flex that the mounting point is allowed so I had to add an angle along the back of it to eliminate the flex.
All the input here is greatly appreciated. Thanks
Eddie

[jiott]

Eddie, sounds like you have thought it thru; that's the main thing. I just thought I would present another way of doing it and why I did it. When you get to this part of the build everyone goes different ways and they all have there little pros and cons.

[efwd]

Well Jim, by all means, continue to offer up the advice. It is very much appreciated and I am pretty sure I speak for Cherrybark too.

[Danzer1]

Ed, don't take all that is written here for hoyle! Do your own research and check with your DAR, FSDO, technical counselor and insurance company.

1) FAR 91.207 (b) states: (b) Each emergency locator transmitter required by paragraph (a) of this section must be attached to the airplane in such a manner that the probability of damage to the transmitter in the event of crash impact is minimized. Fixed and deployable automatic type transmitters must be attached to the airplane as far aft as practicable.

What is "minimized" and "as far aft as practicable" is subject to much interpretation. This is why most certified aircraft have the ELT located in the tail (with access) - certainly all of those are not in arms reach to activate.

2) Having said that, the button on the transmitter is not intended to be there for manual deployment. It is there for testing.

3) Most all ELT manufacturers either require 32" to 36" of separation from other antenna's (ARTEX is one of those). BTW, FAR 43.13 306 g "recommends 36" and refers you back to the the manufacturer for the "required" separation. Whether it works or not is not the point - if not installed per the manufacturers instructions, you could have a legal issue if you were to have an incident (assuming you get it past airworthiness).

4) Most all manufacturers state that unapproved paint or devices shall not be attached or installed on the antenna (whip protector as mentioned prior) (ARTEX is also one of those) for the same reasons as above.

5) Your ELT "annual" does not necessarily coorespond to your "aircraft annual" timeframe. 91.207 (d) states: (d) Each emergency locator transmitter required by paragraph (a) of this section must be inspected within 12 calendar months after the last inspection for......

So if you activated and logged your ELT prior to your airworthiness certificate, the ELT annual must occur withn 12 months of that activation. You can move your aircraft annual up to coincide, but you can't move your ELT annual back.

And of course, lets not forget the requirement to change the battery at half life.

YMMV, Greg

[efwd]

Thanks so much Greg. I just sat down this afternoon before work and read through 52 pages of the ELT installation manual and found everything you mention. Im making the CG issues the argument for keeping it from being installed in the tail. I have not referenced the FAA material yet but the Artex manual states everything you did. I may need to move the antenna a bit to get it away from my VHF antenna. Honestly, anyplace you put an antenna impeads the next ones install location. The airframe is only so big.
Eddie

[jrevens]

...

2) Having said that, the button on the transmitter is not intended to be there for manual deployment. It is there for testing...

Greg

Hi Greg,

My ACK 406 MHZ ELT has 2 little buttons & an LED on its panel-mounted annunciator ... the left one is for "emergency activation", the LED shows you if it is activated, and the right one is for "test & reset".