Pilot DAR: You might be interested in this observation. Many years ago I would routinely fly into Narita, Japan in B747s. In the winter it was common to have descent tailwinds of in excess of 100kts. The aircraft would usually be operated with the speed mode lockes onto 300kts. The first half of the arrival procedure, down to about 20,000ft. would have the full benefit of the entire tailwind. Next the arrival called for a 90 degree turn which resulted in the loss of the entire tailwind component. The aircraft would continue at 300kts. BUT the VSI rate of descent would increase hugely during, and for a time after the turn was complete, before returning to its usual value. Patently, inertia was at play here as the aircraft had to dive more steeply to recover/maintain the IAS. A rather unusual set of conditions no doubt but the "independent in its own block of air" view did not hold here.