Engine Misfire at Altitude.

[n86121]

That’s right

Basic mode a/c a mode A/c transponder without ads b out.

Mode S can be selectively interrogated by radar.
Rather than just interrogating everything in sight.
But even mode S doesn’t have ads b out.

Only mode S extended squitter (ES) replaces w ads vector info.

What I’m hearing is once you get away from major metropolitan airspace,
a lot of smaller aircraft not equipping w ads b

If they don’t go into the airspace that requires it,
they don’t have to get it.

It’s a mixed blessing. Great where everyone has it,
but no guarantee one is seeing everyone else.