Stefan wrote:
Greg Arnold schrieb:

When you are cruising at 20,000' to 30,000', doesn't the effect of
altitude cause IAS to be substantially less than ground speed?

Vne goes with TAS, not IAS. But then, as it most probably was a wave
flight, there most probably was a wind.

Yes, but in a closed course, the wind is a net loss, not a benefit.