So imagine an aircraft flying north at 75kias in no wind. To turn it through 180deg and fly south at 75kias we have to provide an acceleration in a southerly direction capable of changing its velocity by 150knots.
There is no acceleration in order to change the ground speed, because the aircraft is operating with respect to the airmass, not the earth below. A Boeing 777 cruising at Mach .84 at 38,000 has an IAS of 267, have a stall speed of 205 (cruise speed 1.3Vs) and may be flying in a jetstream of 200 knots. What do you think is going to happen if he turned from a headwind into a tailwind in those circumstances. Not that an airliner is going to fly in that sort of headwind.
A reading of how an INS works may give an understanding.