If you have an airspeed of 65kts and a 10kt headwind, you don't have a "55kt engine component and a 10kt wind component" that would suggest that your engine does not need to put out the same power to maintain that airspeed, this is false. Your engine is pulling you through the airmass and is giving you 65kts airspeed. The air happens to be travelling at 10kts across the GROUND in the opposite direction. Your 65kt airspeed translates to a 55kt ground speed.
AerocatS2A: thanks for your correction. But I am unclear about the above.
Do you mean if a 65kts airspeed should be maintained, the engine output should be the same nomatter how strong is the wind? if this is right, am I correct to say that the airspeed is totally unrelated to the wind speed (I think this is not true, right)? I am wondering if we can "suspended" an airplane airborne without thrust (maybe done by a expelling an airmass downward, like a heli?), while the headwind is 10kts, what will the airspeed be?
I am still pondering the issue of airspeed/groundspeed and windsheer. May I PM you for clarification of something
phnuff: can you also forward the messages to me?
Tinstaafl: I like your idea of slidewalk. That helps my understanding. So the change of momentum/inertia when you first stepped on the slidewalk can be treated as the change of airspeed once you experience the head/tailwind of a windshear, right?