Yea I did
az_gila said:
George's previous comments about the ELT location are not quite strong enough. It's not a "manufacture's recommendation" it's actually a FAR.
George said to be honest with the tax man in another thread.. be honest with the FARs too...
gil in Tucson
Thanks for keeping me honest and agree with you but I have a different interpretation. I think I covered my bases. We are talking about antennas right? FAR's especially part 91 does not really address installation in detail. In fact it only makes a few wishy washy references, I highlight below.
As far as FAR's, my previous bullets are right on, even tough I did not refrence the FAR directly. However I do think the real devil is in the details, and those are in installation instructions for the TSO'ed ELT.
If an AP installs an ELT in a factory plane they will follow the FAR's but will follow the manufactures recommendations which are TSO'ed and much more detailed and are really binding. You MUST follow the instructions for a TSO installation in a factory plane. Do we (RV'ers) need to meet the TSO? OK lets say we do.
Now for the CLOUDY FAR's:
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The only significant par about the antenna is:
"(4) The presence of a sufficient signal radiated from its antenna."
(says nothing about where or how to mount it)
The second Par of significance regards the ELT Tx'er location not the antenna:
"(2)(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 kind of word is practicable, only in the FAR's )
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However who is to say what is practicable? (feasible, possible, Usable for a specified purpose).
Hey if your CG calls for all equip mounted forward of wing spar than under the panel is OK. It looks pretty safe there? Why not? Are there other areas in the plane that provide "probability of damage to the transmitter in the event of crash impact (to be) minimized"? Sure. How aft does that need to be?
From the above we MUST mount the ELT practicable aft, usually the tail cone. Sure why not. It is probably the best place from common sense.
More specifically you will follow the ELT manufactures recommendation.
Why is my ELT in the baggage compartment not the tail cone? One thing it is as far aft as practicable and unlikely to be damaged in a crash!!
EBC makes an ELT (TSO'ed FAA approved) with an integral antenna for in cockpit mounting, right. It has to mounted in the cockpit and so that is as far aft as practicable.
http://www.wingsandwheels.com/page13.htm
My theory is I want the ELT antenna with a window view to the outside world thru the plexi canopy (just like you get with an EBC unit). To keep the coax short and still provide protection to the ELT transmitter, the baggage compartment is as FAR AFT AS PRACTICABLE!
It works for me.
Mounting the ELT on the floor, protecting it from being hit with a cover and mount the antenna nearby, as I show in the flipped RV-6 picture, I think meets my installation instructions and intent of the FAR's.
My ELT's generic "TSO'ed" instructions, recommend a typical ELT location aft of the baggage compartment but must be able to access it (to remove after accident) and antenna be near it. The antenna needs to be mounted external, top and vertical. My cockpit mounted ELT antenna is on "top side of the fuselage", external (at least electrically thru the plexi) and vertical? That's my story and I am sticking to it. Since EBC has the same antenna location for their ELT's, if it works for them.........
I am playing a game with you, but builders do mount ELT stuff any old goofy way that may not meet the spirit of the Regs or installation instruction. Why? To hide it and gain 1/3 mph.
People also get philosophical about ELT's, like if I crash I am dead and if not, I'll get out and use my Cell phone or other rationals. I don't feel that way. I want to give it a good "practicable" chance and attempt to meet the spirit of the rule and Regs.
Does an ELT under the panel meet the Regs? I guess you could make a case for it. What about antennas burred horizontal under fairings, cowls or wingtips. Uhaaaaa probably does not meet standard antenna installation instructions like: external, vertical, top of fuselage, close to the transmitter. So I agree with you, but think I meet FAR 91 and TSO'ed instructions. Again that's my story and I am sticking to it.
George