ADS-B [0] is going to be required equipment in all airplanes by 2020. The problem is there are a LOT of general aviation aircraft out there.
Drive by a GA airport and look at all the planes; many of them are 30, 40, sometimes 50+ years old. Now, this is not a big deal in the aviation world. Airplanes are pretty simple compared to most modern cars. They are also required to be inspected once a year by a mechanic (an "annual"), engines are replaced or rebuilt after a certain time interval has passed (usually around 2000 hours), extensive documentation is required to be kept, etc.
But there are just a LOT of them out there, so refitting all of them takes time. Unlike the car world where, if you make a change in the law, you can reasonably expect in 10-15 years the majority of cars would be compliant just because people buy new cars. In the aviation world that isn't the case. New airplanes can easily run $200k+, so people hold on to airplanes for decades.
It's also expensive. Anything involving airplanes is hellishly expensive. :)
You're looking at probably about $5k for equipment + installation costs (which must be done by a mechanic, pilots generally aren't allowed to work on their own aircraft [1]). And that only broadcasts your position; a separate ADS-B receiver must also be purchased if you want to actually see other airplanes around you. The cheapest one I can find is $500, and that also requires a tablet and software.
So yeah, we're going to get there. But it's going to take some time.
You CAN, and that might be suitable for a ground station that's not moving and just providing interesting information to the Internet.
It's an entirely different matter to take that into an airplane and use it in such a way as that my life depends on the accuracy of the information. Has it been extensively tested in actual airplanes in real-life flying? Does it work with and not interfere with other aircraft systems? Does it work with the software I already use and know well?
Yes, $100 < $500. Now, if I built my own airplane (something I've given some thought to doing), I might be a little more willing to experiment with it. But the majority of pilots are not hardware hackers. They're average, everyday people.
I will happily pay $500 for a tested piece of hardware that is guaranteed to provide accurate information and work in my airplane over something I homebrewed using instructions I found on the Internet. My safety is worth the extra $400.
Drive by a GA airport and look at all the planes; many of them are 30, 40, sometimes 50+ years old. Now, this is not a big deal in the aviation world. Airplanes are pretty simple compared to most modern cars. They are also required to be inspected once a year by a mechanic (an "annual"), engines are replaced or rebuilt after a certain time interval has passed (usually around 2000 hours), extensive documentation is required to be kept, etc.
But there are just a LOT of them out there, so refitting all of them takes time. Unlike the car world where, if you make a change in the law, you can reasonably expect in 10-15 years the majority of cars would be compliant just because people buy new cars. In the aviation world that isn't the case. New airplanes can easily run $200k+, so people hold on to airplanes for decades.
It's also expensive. Anything involving airplanes is hellishly expensive. :)
You're looking at probably about $5k for equipment + installation costs (which must be done by a mechanic, pilots generally aren't allowed to work on their own aircraft [1]). And that only broadcasts your position; a separate ADS-B receiver must also be purchased if you want to actually see other airplanes around you. The cheapest one I can find is $500, and that also requires a tablet and software.
So yeah, we're going to get there. But it's going to take some time.
[0] https://en.wikipedia.org/wiki/Automatic_dependent_surveillan...
[1] Unless you are a mechanic yourself or you are flying a homebuilt experimental airplane that you were the primary builder.
[2] http://www.sportys.com/pilotshop/dual-xgps170-ads-b-receiver...