Mr Optimistic asks:
Originally Posted by Mr Optimistic
How did this thread get to 5 pages
Because there are at least two coherent possible definitions out there, and people are voting one by one for their favorite. Mostly without giving coherent reasons for so doing, unfortunately.
Originally Posted by PPRuNe Pop
its STILL the speed of the aircraft relative to the ground!!
Lots of people have said this. One must ask "what do you mean by that?", because there are at least two coherent interpretations, as we have seen.
Originally Posted by PPRuNe Pop
It is not necessary to add anything more than plus or minus wind speed.
Looks like he votes for Kayton.
Then there is
Originally Posted by Pontius's Copilot
Rate of change of position!
Rate of change of position with respect to what? With respect to the fixed stars?
Best to illustrate with the questioner hisself:
Originally Posted by Mr Optimistic
Two observers on the ground (ie dirt, either geoid, ellipsoid or prolate spheroid), measured distance apart. Aircraft flies directly over the two of them. From observer zenith (straight-up) to observer zenith measure the time taken. A bit of arithmetic and hey presto ground speed !
So he votes against Kayton.
Originally Posted by Mr Optimistic
If aviation has managed to come up with an alternative definition I'll be unsuitably impressed.
I guess he has not yet checked for himself.
And so it goes on!
PBL