Yeah when you exceed 300m/s (More or less 1 Mach) then you have broken the sound barrier.

That is why we always first hear the sound of an aircraft before we potentially see it. Because of sound moving ahead of the aircraft.

When you exceed the 300m/s mark you break the sound barrier and are equal or faster then the sound, meaning sound is now behing you.

Sadly FS does not simulate this, sound at 200m/s & sound at 300+m/s sounds the same.

It also does not simulate the occurance of the "compression cloud"  that sometimes happens when one is close to and/or have broken the sound barrier.



The f-18 is well capable of breaking the sound barrier.

Quote:

There's a sonic boom effect for FS9. I'm not sure if it works in FSX. Looks & sounds good but more of a gimmick than anything else. The only way to tell you've exceeded Mach 1 from inside the cockpit is by looking at the Machmeter. [/quote]


Well, there's an effect for FSX, too (or maybe the FS9 one works with FSX) since I use - I think - the F14 from SimV that has this feature of a 'white cloud' and some sort of sound when braking the barrier.


And afik the sound generally (not necessarily faster than the sound) is heard a bit later then the object is seen (made a little graphic) - but maybe I'm wrong: