Overspeed at different altitudes (a320n FBW)

[CaptainRude91]

I think that might be a different unrelated problem, the OPs question is clearly regarding the overspeed limit reducing with increasing altitude:

@KarmaWhiskas

What I don’t understand, why is the overspeed limit lower on the higher altitudes? On FL350 you can’t go above ~280knots in a A320 neo and on low altitudes you can easily go to approximately 340 knots. Since the airspeed indicates how much air particles we hit, why does this speed change?