Originally Posted by
PDR1
So you choose a ground-centric reference frame for the velocity vector, but a anthropomorphic reference frame for the maginitude?
Do you apply the same criticism to a Cessna flying on an East heading in an East-to-West wind?
I'll tell you the same thing I told Brercrow: Look at scenario A, and see that everything checks out, as should be common sense to a private pilot. Then see how every element translates to scenario B. I'll even paste it right in here so you don't have to scroll up. Have I made any mistakes in the translations?
Scenario A (Cessna)
final groundspeed minus initial groundspeed
(airspeed + tailwind) - (airspeed - headwind)
(100+10)-(100-10)
110-90
20
Scenario B (Person inside airliner)
final groundspeed minus initial groundspeed
(airspeed + tailwind) - (airspeed - headwind)
or, if you like:
(walk + tailwind) - (walk - headwind)
(1+500)-(1-500)
501-(-499)
1000