Practically, the best thing to do (in a radar environment), is to make your RTF call:. .. .'Pan Pan Pan, London Control, Bloggsways 123, emergency descent, descending FL100, we can fly radar headings'.. .. .This will enable the controller to shift you away from the thirty aircraft under you, rather than the thirty aircraft away from under where you're going. Especially important where those aircraft are under control of another sector.. .. .Also, in an SSR environment, squawking 7700 will 'force' your datablock through onto the displays of the controllers working airspace under you, who have height filters on to display only their traffic (and a bit more, vertically speaking), thus enabling them to see you coming before you plummet into 'their bit' (technical ATC term) at 6000fpm plus.. .. .Perhaps a couple of current ATCOs could back this up and add to (or even subtract from) it? (eyeinthesky, where are you when I need you?). . . . <small>[ 16 March 2002, 23:08: Message edited by: NorthernSky ]</small>