Tailbeacon with obstruction

Chrisgoesflying

Cleared for Takeoff
Joined
Dec 7, 2018
Messages
1,177
Location
Too far north
Display Name

Display name:
Chrisgoesflying
I already asked this question in another thread but kind of hijacked my own thread there and didn’t get a whole lot of answers, so here it goes again: I may have to fly into US ADS-B airspace more frequently from this fall. Obviously the cheapest and fastest solution is a tailbeacon (i don’t want the skybeacon as i just installed brand new led red and green wing tip lights). My Comanche has two tail lights. One is above the stabilator, the other one below the stabilator. I can’t install the beacon above the stabilator because it would interfere with the stabilator’s travel. so, can i install the tailbeacon below the stabilator or does the unit absolutely need an unobstructed view up for the gps to work?
 
Not an engineer or GPS expert, but I own a PA-24 and just looked at the stabilator area. The lower beacon will experience significant shading from the stabilator. There may be times when there are enough visible satellites to give a valid GPS signal, but I believe that you will not get reliable coverage. I have to think there will be significant amounts of time when there is no valid GPS position. And the system will notice that your ADS-B performance is not up to snuff.
 
It would help if we knew what radios and transponder you currently have in order to make a recommendation for a path to compliance. But without knowing anything, I’d suggest the GDL82.
 
IME, the TailBeacon GPS barely passes the FAA ADS-B performance test under ideal conditions. I had to install filters on the radios, modify the grounding at the tailplane, solder instead of crimp its power line, even replace the switches in my panel, just to get it to pass. After all this work it does pass, but only just. And this is installed at the top of the tail of my 172 without any obstructions. If there were any obstructions I can't see it passing.
 
It would help if we knew what radios and transponder you currently have in order to make a recommendation for a path to compliance. But without knowing anything, I’d suggest the GDL82.

1980s (and older) avionics so nothing that would get me close to compliance.

Transponder is a KT76A and radio is a SL40.
 
1980s (and older) avionics so nothing that would get me close to compliance.

Transponder is a KT76A and radio is a SL40.

What is the latest information on Canadian ADSB compliance and do you intend to comply with their requirements at some point?

With what you’ve got for radios right now I can understand the desire for a simple add on means of compliance. You might be able to find a used GTX335 with built in GPS for cheap enough that it would be worth considering a transponder upgrade/replacement but a used GDL82 would probably offer the cheapest and most solid operation option for compliance.

Both the uAvionix beacon and the GDL82 are UAT compliance options, so another consideration is if you see yourself ever going where 1090 is required.
 
What is the latest information on Canadian ADSB compliance and do you intend to comply with their requirements at some point?

With what you’ve got for radios right now I can understand the desire for a simple add on means of compliance. You might be able to find a used GTX335 with built in GPS for cheap enough that it would be worth considering a transponder upgrade/replacement but a used GDL82 would probably offer the cheapest and most solid operation option for compliance.

Both the uAvionix beacon and the GDL82 are UAT compliance options, so another consideration is if you see yourself ever going where 1090 is required.

I am most likely moving to the US so Canadian compliance is not that important to me. The few times i will have to go to Canada, i’ll avoid ADS-B airspace. Plus, i think the earliest they’ll mandate ADS-B in airspace a GA pilot would typically fly in is 2028. They may change their mind 5 times by then.
 
What is the latest information on Canadian ADSB compliance and do you intend to comply with their requirements at some point?

With what you’ve got for radios right now I can understand the desire for a simple add on means of compliance. You might be able to find a used GTX335 with built in GPS for cheap enough that it would be worth considering a transponder upgrade/replacement but a used GDL82 would probably offer the cheapest and most solid operation option for compliance.

Both the uAvionix beacon and the GDL82 are UAT compliance options, so another consideration is if you see yourself ever going where 1090 is required.
I believe NavCanada has softened on the diversity requirement and as long as you can pass a performance report in Canada you're good to go
 
Not an engineer or GPS expert, but I own a PA-24 and just looked at the stabilator area. The lower beacon will experience significant shading from the stabilator. There may be times when there are enough visible satellites to give a valid GPS signal, but I believe that you will not get reliable coverage. I have to think there will be significant amounts of time when there is no valid GPS position. And the system will notice that your ADS-B performance is not up to snuff.
Signal blockage is is pretty much the reason that the SkyBeacon (the one that replaces the strobes) cautions against installing in Comanches with tip tanks.
 
I think I found my solution. I'm looking to install a WAAS GPS soon anyways so when I do that, I'll get the Trig TT31, hook it up to the WAAS of the GPS and I should be ADS-B compliant. The Trig transponder is a direct slide in replacement for the KT76A.
 
I am most likely moving to the US so Canadian compliance is not that important to me. The few times i will have to go to Canada, i’ll avoid ADS-B airspace. Plus, i think the earliest they’ll mandate ADS-B in airspace a GA pilot would typically fly in is 2028. They may change their mind 5 times by then.
Last I read, Canada ADS-B is satellite only, no ground stations, and required for GA only at 12,500' and higher.
 
Last I read, Canada ADS-B is satellite only, no ground stations, and required for GA only at 12,500' and higher.

That’s what they’re saying now. They’re planning to have something implemented for airspace around larger airports akin to the US at some point but nobody, including themselves know what exactly.
 
My Warrior's tailBeacon has been flawless. I installed it, replacing the existing taillight, and ensured the ground connection jumping the rudder gap was good. Installed the app, adjusted the threshold once after the first flight based on the PAPR, and that's been it. Every few flights I request a PAPR. All good. But the unit is NOT shielded from the sky by the stabilator.
 
I think I found my solution. I'm looking to install a WAAS GPS soon anyways so when I do that, I'll get the Trig TT31, hook it up to the WAAS of the GPS and I should be ADS-B compliant. The Trig transponder is a direct slide in replacement for the KT76A.

Kill two birds with one stone - Garmin GNX 375. You'll also get ADSB In as a bonus.
https://www.garmin.com/en-US/p/577174

1721094600571.png
 
Kill two birds with one stone - Garmin GNX 375. You'll also get ADSB In as a bonus.
https://www.garmin.com/en-US/p/577174

View attachment 131368

That would probably be the most cost effective solution! I'm afraid the screen is too small but at the same time, it's right in front of my nose anyways so maybe fine. The only other thing, it doesn't have comm. I wanted to install a WAAS GPS with radio so I have a second radio. Maybe having a second radio isn't really needed?
 
The next larger screen would be the GTN 650xi. I like that size as well, but I'm currently flying with a GNC 355 (GPS with a COM) which is same size as the GNX 375 and it works just fine.

IF you want a second radio you could install PS PAR 200B audio panel. You'll need an audio panel for a second radio anyway, and this one has one built it.

I have one in the plane I just bought and it works great. Unfortunately, I have to take it out in the next few months. I'm adding a GTN 650xi to go with the GNC 355, and the PAR200B is only a two com audio panel.


1721096534570.png
 
I think my current audio panel is the most modern piece of equipment on the plane. I currently have two radios on board but one is so ancient, I can't wait to kick it out. I was thinking to kick out the ancient, gigantic radio and in its place put a larger GPS/Com unit and then replace the xponder with a slide in replacement capable of ADS-B out. However, the GNX 375 does look appealing so maybe the solution is to take out the xponder and install the GNX 375 and then find a slide in replacement for the ancient radio so I'd still have two radios just in case.
 
I think my current audio panel is the most modern piece of equipment on the plane. I currently have two radios on board but one is so ancient, I can't wait to kick it out. I was thinking to kick out the ancient, gigantic radio and in its place put a larger GPS/Com unit and then replace the xponder with a slide in replacement capable of ADS-B out. However, the GNX 375 does look appealing so maybe the solution is to take out the xponder and install the GNX 375 and then find a slide in replacement for the ancient radio so I'd still have two radios just in case.
Between the GNX375 and the GNC355, I prefer the 375:

What's the COM radio you're looking to pull out?
 
Back
Top