Is 978 UAT monitoring worth while?


I have seen a few older subjects on 978 MHz UAT monitoring. Has anything improved since the last post in 2016? I ran my dongle on HDSDR at 978 MHZ and I dont see any signlas but that doesnt mean much. Any ideas?


Where abouts are you located? My understanding is that this is only relevant in the US.


United States, Texas.


It’s a matter of opinion. There are aircraft there that you can track that are not trackable via 1090ES. You’ll probably see more in larger cities with more general aviation traffic. It will be (generally) smaller aircraft that don’t fly above 18,000 feet. There are some helicopters there and, if you’re near an airport, ground vehicles.


There is a major aircraft gathering in the USA generally known as Oshkosh. There are generally over ten thousand light general aviation aircraft that attend. It is underway this week (July 2018)

One of the avionics manufacturers will be showing its just FAA-approved UAT system. It can be installed in less than 1/2 an hour and sells for $(US)1849. Total installed cost should be around $2000. That is about a third of the installed cost of previously available 1090 systems. There will probably be a increase in UAT equipped aircraft as a result.


Even at $2k that’s expensive considering a Raspberry pi or Stratus cost a tenth less than that. Yes they are not as robust or FAA approved but surely the cost can still come down and people stop milking the cow…


If you consider that the $1849 unit must operate “outdoors” and function while transiting from very hot to very cold in a matter of minutes, contains a computer, a precision GPS source, a GPS antenna, a UAT978 antenna, a position strobe, a navigation light, a short-range wireless transceiver, and a power supply for all of the sub-systems, the price is not outrageous. On top of the cost to design and build the units, the cost per unit to amortize the FAA’s very burdensome Technical Standard Order (TSO) process is substantial.

The unit had to demonstrate compliance with the following TSO’s:
UAT Transmitter: TSO-C154c Class B1S
WAAS GPS: TSO-C145d Class B 1
Pressure Altitude Reporting Equipment: TSO-C88b
Position Lighting: TSO-C30c
Anti-Collision Lighting : TSO-C96a

These units, and other manufacturer’s ADS-B equipment, will become the primary means that the FAA uses to keep planes separated starting in 2020. Pilots do not want to trust their lives and the lives of their passengers to some untested/unqualified (not TSO’d) unit.


RPis are great, but far from being reliable enough to be installed on planes. Hopefully never on a commercial plane. Even private planes, if they share the same air ‘lanes’ with commercial traffic.

Lets face it, if one can afford to buy and maintain a plane, a one time $2k expense is nothing.


Awesome response as this is what people need to hear, the reason why the costs are the way they are and the differentiation to cheaper home made solutions.