I'm sure this has been asked before but I keep getting conflicting opinions from pilot colleagues.
Say I'm at FL380 with 20 miles to run to my descent point when I get the following instruction: "Descend FL290, 2000fpm or greater". So this takes me below my ideal descent profile.
As I'm passing FL320, I then receive "Descend FL220" from the same controller. Now, I understand this is a new clearance which replaces the old clearance, so I can descend at, say, 1000fpm, to get back on my profile.
But some would say you should maintain 2000fpm until FL290. Who's correct, and is there a written reference?
Many thanks!
