??? I misunderstood you to mean the angle between the apparent source of the sound and the apparent source of the reflected light from the jet. Perhaps you could draw it out to explain what you are looking for.
If the jet is flying at your altitude directly at you, it appears as a speck and the speck just gets bigger as it comes closer and closer to you. The sound comes from the speck. There can be no delta.
I guess at the exact instant the jet flies over your head there would be some delta, but at that moment the jet is almost directly on top of you. Sound traveling a few inches from the jet engine to your ears, even as slow as sound is, would happen pretty quickly in comparison to the jet moving (which is slower than sound)
