Objects in the distance in the Milkman Conspiracy
In the Milkman Conspiracy, from the telephone pole outside the Rainbow Squirts' house. Look out over the next telephone pole and there's a stationary black dot. In first person view it's in the middle of the screen when the top of the next telephone pole is at the bottom of the
It's there before and after Raz defeats the Den Mother, so it's not a helicopter. It can be seen from atop the telephone pole outside the Book Repository, but only if you're looking right at it. It doesn't get much larger if Raz jumps the telephone lines and floats toward it.
There's another, fainter, one to the right and up just a little. After defeating the Den Mother one appears directly overhead as well. None below where they could be floated to.