It amazes me that some professionals here are trying to lay blame to the controller when the crew did not using the correct (and the most simple) phraseology! "we are declaring an emergency etc etc etc"? if it were medical, a tad embarrassing if the controller put on a full emergency as he hasn't heard properly or missed some of it (on the phone, a colleague talking to them etc) or it would need to controller to clarify the situation by which time the crew are then focused on the problem. As already said many times, MAYDAY or PAN MUST be used if you want to declare. Even MAYDAY x 3 and callsign and nothing else will get the fire vehicles moving! Doesn't take a crew discussion to figure it out, it's instant! Just last week I had an aircraft on frequency, crew said they'd like to return due to a technical issue, nothing declared. Several minutes later I observed the aircraft slowing down and tracking towards nearest landfall, on asking the crew to confirm the issue- "eerm, yeah, pan pan....", THEN we set the wheels in motion for an emergency landing, actually resulted in a forced landing at a disused airfield. If they waited any longer to declare, emergency services would not have been there on arrival. Remember the Avianca near JFK??? Every presentation I've been to where that crops up results in the same 100% agreement between all there, they should have declared an emergency! You need less thinking to say Mayday / Pan, and it works! Anything else may not work.....