My employer has found it necessary to remind pilots operating in and out of Bristol that ATC has no authority to permit pilots to exceed 250kts below 10,000'. I believe that many pilots are not aware that ATC doesn't have this authority, and when they call inquiring about speed restrictions the 250 kts below 10 is the restriction they are referring to.
At the risk of muddying the water, I have noticed that in controlled airspace, after ATC allows a pilot to maintain high speed during the descent, he tends to maintain high speed all through the approach. It is my understanding that if a pilot has been given an ATC instruction ie "maintain heading ---", this instruction is cancelled on frequency change, unless the pilot is instructed to advise the new controller of the clearance. The same philosophy apples to an instruction to maintain high speed. Is my understanding correct, or am I about to be taught the error of my ways?