Interestingly enough, I have an app on my phone which has radar tracking of aircraft etc, this app also sends an alert when an aircraft in the world squarks emergency codes. Yesterday I received an alert which when the app is opened, takes me to a satellite view with the aircraft superimposed over the top. This aircraft squared 7700 and I could see by the information provided in real time by the app that the altimetre was unwinding pretty rapidly, did not time the decent however remember thinking that it must have been a cabin pressure problem, as the aircraft defended to 11500 feet if I recall and I could see it diverting to Rockhampton. Great little app. I was able to watch my wifes aircraft all the way from Melbourne one time and saw it safely land in Brisbane. I could even see that it landed on 01.