ELT Antenna Options ?
 

Manufacturers suggest the antenna should go on top of the fuse in front of VS for low wing aircraft. I don't recall photos of an antenna there on an RV. Where have you put yours ??
A blade antenna would be preferred over a whip for aesthetic and drag considerations. A kannad blade is $2,700. Are there affordable blades that will work for an ELT ??
As always, I appreciate your help.

On top of the fuselage in front of the vertical stabilizer!

Under cowl
 

On my RV-3B the builder put it under the horz/vert stab fairing. No Idea how well it works.

In the RV-4 I'm looking at mounting it on the firewall (as ground plane) sticking forward under the cowling. Looking at mounting the ELT in the pilot stick well. Yes, I know, common practice is putting it in the tail, but would rather have it near pilot/passenger.

As for vertical vs horizontal antenna orientation, who knows how the plane ends up.

Finn

Inside....
 

Mine is located inside plane, corner behind pilot, formed by sidewall and baggage bulkhead. I inadvertently jarred it last summer, while on the ground, under the shade hangar, SAR called. YMMV, but it is a radio signal, Omnidirectional.

Mine is on top of the tail cone, in front of the horiz stab, as called for by the ELT mfg. This is on an RV-10.

My understanding is that the regs require you to use the specific antenna called out by the ELT Mfg. (and usually included with the ELT), and that you mount the ELT and antenna as specified. I'm not sure that the regs allow you to deviate from this just because it is being mounted on an experimental aircraft. (But then, how many people follow the regs?)

RV 4 specific question
 

I conclude that the most robust and accessible location for an ELT and Antenna in an RV4 would be integrated with the roll bar. Would the transmission be acceptable through the canopy with the steel roll bar near the antenna.
Still interested in a blade option if you know of Kannad alternate.

DAR
 

You may want to discuss it with your DAR. It would seem that he will have the final say.

I am building a -10 and wanted to mount my ELT antenna beneath the empennage fairing. Ran it by my DAR and he said it needs to be mounted per the radio manufacturer's guidelines...at least if I wanted my certificate.

Soooo, it is on top of the tailbone, forward of the stab...

Three RVs and the ELT antenna is mounted under the empennage fairing on each. While the typical install manual calls for it to be on top, I offer that under the empennage fairing is a far more survivable location. If you really need the ELT, it could well be in a vertical position.

For working, on the RV-10 the new owner inadvertently activated the ELT. The FAA was making calls to his house in a few minutes.

The new RV-8 was signed off a couple of weeks ago. Just like the other two, the inspector did not ask about it.

Carl

Actually, the DAR doesn?t necessarily have a say in it. The ELT isn?t required to get an airworthiness certificate. It IS required for most (but not all) flight operations of course, not arguing that....but just like a transponder cert, it is not a prerequisite for the AWC.

That said, yes - to be a legal installation, the ELT must be installed per the manufacturers instructions/documentation.

And for the RV-3 mentioned above....not required at all....legally....

Paul

I heard the same thing from an EAA Sportair workshop. The ELT is not required for AWC or during Phase1 testing. It may be needed afterward.

I am mounting mine near the pilot rear roll bar so it will provide some structural protection and clear transmission.

Another option which is less expensive and a pretty short antenna is to use the AV-100 antenna (I think this is correct). It is only about 13" long and less than $200.

Two RV's. They are both under the fiberglass empennage fairing. The transmission range may not be quite as good as on top of the fuselage, but in my opinion ELT's are so unreliable that compromising a little on the range is ok.

Question
 

If it isn't required for the AWC, why would the DAR imply that I couldn't get the AWC without a proper, legal installation?

No answer necessary, the FAA is run regionally...

Because your DAR is making up his own rules - I seriously doubt if the FAA inspectors have anything to do with it (unless you are actually having an FAA inspector do your AWC instead of the DAR).

I'm always suspicious of DAR's that make up their own rules.....

yeah, but
 

Got to use someone to get that certificate...

On my RV-10
 

I mounted mine tucked right into the B pillar on the right side. (That's the vertical part of the canopy right behind the door and in front of the rear window.)

Rubber Ducky
 

I mounted a rubber ducky antenna under the canopy right at the edge of the deck just behind the rear passenger seat in my -8. A trimmed piece of aluminum angle has it oriented vertically.

Don

ELT antenna Under the empennage fairing
 

I mounted mine under the empennage fairing on my RV-8. During the special airworthiness inspection, the FAA-actual inspector said "nice installation - that fits well". Then, a year later during paint, the paint shop somehow set off the ELT. I received a call from SAR saying the ELT was active. The airplane was inside a hangar with the fairing installed.

Thus, in my practical experience, the location is satisfactory for a special airworthiness certificate and signal transmission is adequate.

unless...
 

What if you flip over in the accident? Then the antenna would be shadowed by the empennage...




Sorry, couldn't resist...:rolleyes:

When I converted from a 121.5 MHz ELT to the ACK EO4 403 MHz ELT I had to move my antenna from under the vertical stabilizer to on top of the fuselage just behind the rear cargo panel. Why? It wouldn?t otherwise pass its internal system check. It kept giving an error code beep.

In its current location it works fine and doesn?t appear to impact airspeed and doesn?t look bad either. Follow the instructions, you won?t be disappointed. As far as will it work if you?re upside down - well, the antenna is very flexible.

the book says that an ELT antenna is a vertical polarized antenna and should be mounted that way. but, i guess they assume that the wreckage will be horizontal when it stops........

bob burns
RV-4 N82RB