I don't think they understand that changing the SPEED changes the PROFILE of the descent.
A "near-idle" descent at 300 knots will be steeper and be initiated from cruise later than a "near-idle" descent at 250 knots. So, when ATC gives us a slower speed, that immediately puts us HIGH on the NEW "near-idle" descent gradient.
Add to that concept the fact that different pilots in different airframes deal with the same speed changes differently, and chaos ensues.
If I ever get to fly an RNAV arrival into Memphis AS PUBLISHED, I'll probably have a heart attack.
You know, we could establish 4 Gateways and assign everyone an RTA so we could begin planning our spacing and adjusting our speed from Top of Climb. That would save too much Jet A and make too much sense.
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