Poll: Will ADS-B Inevitably lead to user's fees?

[Jay Honeck]

Ok. Let's try this in kid simple speak, since you refuse to read complete sentences.

The only device with anonymous mode is a 978mhz Universal Access Transceiver (UAT) ADS-B Out device. You do not have one of these. You have a Mode-S Transponder, which uses the 1090mhz ES for ADS-B out. This is not a UAT, just like it is not a kangaroo.

Exactly!

The point everyone should take from this is that you can't discuss ADS-B as if it were a single thing. In the brave, bizarro world of the FAA, my compliant ADS-B installation can (and probably will be) completely different than your compliant ADS-B installation. (And my installation cannot be "anonymous".)

Now that we've established that, can anyone explain why ADS-B is essentially two different systems on two different frequencies? Why not one, or the other?

 

[docmirror]

Yes, I can explain it.

 

[ClimbnSink]

Now that we've established that, can anyone explain why ADS-B is essentially two different systems on two different frequencies? Why not one, or the other?

Equal bribes from the companies bidding to build it

 

[Henning]

Exactly!

The point everyone should take from this is that you can't discuss ADS-B as if it were a single thing. In the brave, bizarro world of the FAA, my compliant ADS-B installation can (and probably will be) completely different than your compliant ADS-B installation. (And my installation cannot be "anonymous".)

Now that we've established that, can anyone explain why ADS-B is essentially two different systems on two different frequencies? Why not one, or the other?

Because UAT presented a lower cost alternative that gave something back up to the planes of value. 1090 is the international standard. UAT is a freaking gift to GA.

 

[Pedals2Paddles]

Two reasons, both of which are good ones.

The first and biggest issues is frequency congestion. You can only squeeze so many transmitters onto a frequency at once. 1090mhz is the transponder Mode A/C/S air-to-ground and air-to-air frequency. Literally every transponder in the sky is pinging away on it. It is pretty packed, but it works because each response is short and sweet. And they only speak when spoken too (secondary radar hits or active TCAS).

With ADS-B in full swing, the duration of each transmission increases, and quantity of transmissions increase. The transmission includes way more data, so it takes longer. And the transmissions are constant, not just in response to being pinged. There is no way to fit every aircraft in the United States, plus international traffic, on 1090ES once ADS-B is in full swing. It would just be one huge blah.

The 978Mhz UAT gives us little guys a second option. We can have ADS-B in/out box on a different frequency. We don't need to buy a new transponder. So it takes a load of the 1090ES system. The ground towers manage cross-patching between the two without overloading one or the other. It also much cheaper than a mode s transponder with integration to the panel. A plus for us little guys. It is only for use below 18,000ft and in the United States, which is a reasonable trade off for the lower cost for us little guys.

(If you require flight above 18,000 or internationally, you are required to use a Mode-S 1090ES transponder for the ADS-B out portion.)

The second issue wasn't so much of a problem, but a reason. The FIS-B and TIS-B data services were desired. In-flight weather and briefing type data, and live traffic for your cockpit display of choice. Putting that on 1090ES was entirely impossible for the reasons outlined above. So a second frequency was needed to handle this broadcast data. So it was integrated into the 978mhz UAT system on the ground towers. These services also are presented as an incentive to migrate to ADS-B sooner. A second plus for us little guys.

Of course, for those of you who don't care about weather data, traffic data, or having the latest gizmo, you won't care about these reasons. That's fine. You don't have to. As long as you stay out of Class A/B/C airspace and below 10,000ft, you can continue to not care even after 2020 and not do it.

 

[MooneyDriver78]

Still trying to figure out where the "anonymous mode" switch is in our new panel. Must've forgot to install it.

Ain't no "anonymous mode" on the Trig TT-22, at least not one that is readily accessible.

There is on the GDL-88, you can hook a switch to enable it. So go mode C with GDL-88, if you have mode S then it must be disabled, otherwise you will have 2 identifiers.

 

[John Collins]

Two reasons, both of which are good ones.

The first and biggest issues is frequency congestion. You can only squeeze so many transmitters onto a frequency at once. 1090mhz is the transponder Mode A/C/S air-to-ground and air-to-air frequency. Literally every transponder in the sky is pinging away on it. It is pretty packed, but it works because each response is short and sweet. And they only speak when spoken too (secondary radar hits or active TCAS).

With ADS-B in full swing, the duration of each transmission increases, and quantity of transmissions increase. The transmission includes way more data, so it takes longer. And the transmissions are constant, not just in response to being pinged. There is no way to fit every aircraft in the United States, plus international traffic, on 1090ES once ADS-B is in full swing. It would just be one huge blah.

The 978Mhz UAT gives us little guys a second option. We can have ADS-B in/out box on a different frequency. We don't need to buy a new transponder. So it takes a load of the 1090ES system. The ground towers manage cross-patching between the two without overloading one or the other. It also much cheaper than a mode s transponder with integration to the panel. A plus for us little guys.

The second issue wasn't so much of a problem, but a reason. The FIS-B and TIS-B data services were desired. In-flight weather and briefing type data, and live traffic for your cockpit display of choice. Putting that on 1090ES was entirely impossible for the reasons outlined above. So a second frequency was needed to handle this broadcast data. So it was integrated into the 978mhz UAT system on the ground towers. These services also are presented as an incentive to migrate to ADS-B sooner. A second plus for us little guys.

Of course, for those of you who don't care about weather data, traffic data, or having the latest gizmo, you won't care about these reasons. That's fine. You don't have to. As long as you stay out of Class A/B/C airspace and below 10,000ft, you can continue to not care even after 2020 and not do it.

Great answer.