ADSB help
 

If I have a mode C transponder and install adsb in only, would the only advantage of adding adsb out be that I could fly in B,C, and above 10000' after 2020? ATC would see my transponder and I would see traffic and wx on the in only adsb part linked to a screen. I don't know much about this and am trying to see any advantage of installing in/out over just in. I wish they had made the altitude limit higher, maybe the same as the O2 requirements.

Without ADSB out the traffic information is the air to air signal only. With ADSB out you will also receive ground traffic signal i.e. more better information

Do you ever fly IFR? If so ADSB-In will be required, in addition to the airspaces you noted already.
Also, you will only get traffic if you are near another aircraft that is transmitting ADSB-Out.

Little bit more info
 

Without ADS-B Out come 2020 it's not just the airspace but the area below the airspace also, that is the thing that got me to want it. I have flown to Schaumburg (06C) a few time which is under Chicago O'Hare (KORD) Class B airspace, come 2020 I would not be able to do that without ADS-B out.

Without ADS-B out you do not get all transponder equipped traffic, out allows you to receive transmitted traffic signals from ground transmitters also, not just air to air.

Hope this is making sense, it's really confusing sometimes.

Huh? Do you have a reference for the ADS-B IFR requirement?

Well, I guess if you can always plan flights that avoid flying in or over Class B and C, and stay below 10K, you could get away without. I was thinking more from a practical standpoint. I didn't look to see where his is located.

Technically you are right, not a specific requirement. However, he shows Va as his location. I suspect it will be very difficult to go many places IFR without entering airspace that requires ADSB-Out. It is possible, of course, but I was thinking more from a practical standpoint.

Oh OK -- your post caught me by surprise since you originally didn't qualify the "IFR required" statement like you did above.

I generally concur with your assessment however. Heck we can legally file and fly IFR without a transponder altogether, even after 2020, but that has practical limitations as you noted.

I live near DTW and mostly operate from airports within the 30 mile ring, so I have that mindset I guess. But your're right, should have been more specific on my original post. Good catch!

No worries! I'm based under the Washington DC Class B in the SFRA so my RV-10 was born with ADS-B out from the get go.