Emergency Descent and 7700
I teach A320 Type rating . Up until now , I have suggested that during an Emergency Descent Pilots might think about setting squawk 7700 pdq if for no other reason than to alert ATC in lower sectors that an aircraft is about to plummet into their airspace (Altitude filter otherwise active ) . Someone has now suggested to me that this is unnecessary as ( in the UK , at least ) (i) ATC Software notices the rapid change in Altitude and alerts everyone accordingly and/or (ii) Upper level controllers can Flag a radar return with an Emergency code , which then makes the aircraft visible to all .
So : some questions for you controllers
1. Has what I have been suggesting ever been the case ( squawk A7700 for lower level conspicuity , or was this a figment of my imagination ?
2. If it ever was a good idea , is it now ( over UK) ?
3. Would the same answer to 2 apply over Maastrict; Rome ;Turkey ? (etc etc)