Question About Sonic Boom And Wind Speed .....

[Gizmonster]

A friend asked me a rather random question the other day:

He read that a plane crossing the Atlantic recently, had a tailwind of approx 200 mph and as such, its speed, relative to the ground, exceeded Mach 1 - approx 800 mph.
However, its speed relative to the air it was travelling in would be much less than Mach 1 - approx 600 mph and we're both in agreement that even though it's ground speed would exceed Mach 1, no sonic boom would be heard, as its speed relative to the plane's immediate surroundings would be less than Mach 1 and wouldn't be able to generate a sonic boom.

This is only our thoughts - anyone care to add their two-penneth??

[Atheist]

I presume that if its airspeed was less than the speed of sound, then there would be no sonic boom.

[THECORBYLOON]

If the airspeed is lower than the local speed of sound, there would be no boom.

[Gizmonster]

I was hoping for a few more replies, but hey ho .... thanks for replying and corroborating what we both think.

I like to award a BA where I can. Both answers are almost identical, so Atheist gets it, just for answering first :)