First confirmation I've found so far on this exact question: "XB-1 is supersonic! (No boom audible here, as expected)" - Jon Ostrower https://bsky.app/profile/jonostrower.com/post/3lgsvea6zbs2x

Raises more questions though, because there were two other chase planes. Did the other planes stay below the sound barrier at all times?

Edit to add: Was no audible boom expected because of the planes themselves or because of where the people were watching from?

With planes being long enough away from the demonstrator, and speed of sound relatively low (about 330 m/s), the booms of all three planes should be separate enough, e.g. a good 100 ms away from one another, even if all three went supersonic and were dragging their respective shock waves.

The distance between the planes appeared to be around 30-50 m at the supersonic transition time, as much as I can estimate the size of the planes. A sound recording made under the flight path should allow to measure how many dB was the demonstrator's boom.

I don't see the problem? I was just saying that "not noticeable" is a really high bar to set for a supersonic flight.

But your first sentence reads like a direct answer to the question:

> Was the sonic boom noticeable?

> Noticeable is certainly a way of putting it.

As in, "Yes it was noticeable, and then some." At least, that's how I read it.

That's not even close to what I intended.