Descent restrictions

[stinker]

Descending on arrival into UK airport. Told to be FL 200 at x miles from xyz. Then cleared FL 150 to be x miles from xyz. Was under the impression that this cancels the FL 200 restriction - other crew member says "it does but air traffic like you to comply with FL 200 restriction anyway for other traffic" - is this true or bluff ?

[identnospeed]

Stinker

This subject is covered on previous threads including :
http://www.pprune.org/ubb/NonCGI/Forum6/HTML/000419.html

and
http://www.pprune.org/ubb/NonCGI/Forum6/HTML/000307.html

regards

INS

[stinker]

identnospeed - question answered amply.
Thanks.

[MUAC_DELTA_ATCO]

Just wanted to add something to this from the other side of the channel.

The new clearance automatically cancels the preious clearance as with all instructions issued in ATC. If we need you to comply with the first restriction for traffic reasons we will specify it.

However, most controllers find that saying 'descend FL150 to be at level at xyz AND to cross point abc FL190 or below' quite a mouthful, not to mention confusing to pilots. This is why at Maastricht UAC controllers generally prefer to issue a calculated descent rate when required for traffic, which in turn means the a/c is automatically FL150 at or before point xyz.

Less r/t, less room for error, more time for us to think about other traffic problems.

[This message has been edited by MUAC_DELTA_ATCO (edited 13 October 2000).]