I was with a fellow last night who mentioned the pressure control system in a triple 7 is fully automatic. Not sure if the is an override.
There was also a NYtimes article yesterday that recommended that transponders should not be allowed to be turned off and this would have allowed for better tracking. I'd be interested in the comments of cashflyer and the other pros.
http://mobile.nytimes.com/2014/03/18/opinion/out-of-control.html?_r=0&referrer=