Originally Posted by
ChristiaanJ
henra, you're making a mistaek....
Your aircraft has mass/inertia, so it will not be instantly dragged along by your 100 kts tailwind. Your airspeed will now be 0 kts. Not a healthy situation....
Read up about windshear (not exactly the same, but similar).
That is EXACTLY the point I was trying to make.
It was my point about change of state of the reference system in reply to his remark:
Yeah, suppose the windspeed goes from 100 knots back to zero, does this change the Ekin of the airplane ? If not, then you will need to take the groundspeed as speed reference.
My point being that for the problem of loss of effective Ekin to trade for altitude it makes no difference if you have a headwind of 100kts while flying 100kts, i.e. being at a standstill with regard to the ground and the wind suddenly stopping or
you are flying at 100 kts and are suddenly hit by a 100kts tailwind. In the latter case you have no airspeed left to fly after being hit by the wind either.
Seems my explanation was a bit brief last time..
Edit:
To give another example:
You have a Microlight tied to the ground and the wind is blowing at 70kts. What will happen if you cut the ties?
It will lift off and start to fly backwards with regard to the ground. You have traded speed for altitude at that moment. And it had kinetic energy with regard to the air at that moment although with regard to the ground it didn't. It's all about relevant reference systems....