QUOTE(Piltdown Man @ Mar 27 2008, 11:32 AM) [snapback]126160[/snapback]
Last night, whilst speaking with a jolly nice chap from Swanwick (London Control), he noticed that our new cleared level hadn't yet been selected on the Flight Mode Panel (FMP - the place where you set your speed, heading, nav. mode, cleared level, V/S etc.). Interesting eh? When asked, "Yes" he said "I can now see all of your FMP settings - you can't cheat any more". But he couldn't tell what the cabin crew looked like or where they were. We do have some privacy!
What? That's a new one...though I always thought what Mode S did different than Mode C, never took the action to look it up.
Another mode called Mode S (Selective) is designed to help air traffic control in busy areas and allow automatic collision avoidance. Mode S transponders are compatible with Modes A & C. This is the type of transponder that makes the ACAS II (Airborne Collision Avoidance System) and the ADS-B (Automatic dependent surveillance-broadcast) systems function.
Mode S is mandatory in controlled airspace in many countries. Some countries require that all aircraft be equipped with Mode S, even in uncontrolled airspace. However in the field of general aviation, there have been objections to these moves, because of the cost, size, limited benefit to the users in uncontrolled airspace, and, in the case of balloons and gliders, the power requirements for these aircraft that do not have electrical systems