AerocatS2A
Hmm I've thought long and hard about this and , yep you are right, I am mixing air and ground speed. I stand corrected. As for jetstreams, well since sitting in a jetstream will shorten a flight by increasing groundspeed for a given airspeed, that will equate to a lower fuel burn and therefor more economic flight (or am I wrong about that?)
Mad (Flt) Scientis
I think the mixing of air and ground speed answers explains my confused message too. Again I stand corrected